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DISCUSSION => Engine + Driveline => Topic started by: bearsbmw on November 14, 2008, 11:02:25 PM

Title: Cold start engine shakes and sputters
Post by: bearsbmw on November 14, 2008, 11:02:25 PM
Ok this problem is driving me bonkers as I have been trying for a month to figure out the problem and I can't seem to get my finger around it ...  basicly on cold start the engine shakes and sort of sputters a bit. Once it clears up, it runs very well after about a min... there is a few thing's that I can do that will clear this problem up befor I start in the morning and that is Unplug AFM or make a small vaccum leak

What the heck is going on !!

Thanks!
Title: Cold start engine shakes and sputters
Post by: AcSchnitzer318is on November 14, 2008, 11:23:27 PM
This problem is driving tons of us up a wall.  Get used to it... I've been dealing with it now for a year +.  ;)
Title: Cold start engine shakes and sputters
Post by: B318M42W on November 14, 2008, 11:38:20 PM
here's my 2 cents... if you need to make a vacuum leak to "fix" the problem, then it means that the engine needs more air to get the "right" air/fuel mixture... so maybe...
- AFM is dirty or dying
- ICV is dirty or dying
- cold start injecter is not well operating
- fuel isn't "atomised" well enough???
- ECU's loop mode

first things to come to mind... hope it gives you an idea!
good luck
Title: Cold start engine shakes and sputters
Post by: bearsbmw on November 14, 2008, 11:41:20 PM
Quote from: AcSchnitzer318is;60768
This problem is driving tons of us up a wall.  Get used to it... I've been dealing with it now for a year +.  ;)


I was hoping someone would shed some new light lol with a new thread was expecting the deal with it part :D
Im too lazy to read the big thread on this same problem but did you replace your fuel regulator and knock sensors?
Title: start trouble
Post by: roundel318 on November 14, 2008, 11:44:26 PM
I like the cold start injector idea.....
Would a wonky O2 sensor cause this?
I wouldn't think so as it would probably cause trouble all the time?
Just thinking out loud.
Title: Cold start engine shakes and sputters
Post by: bearsbmw on November 14, 2008, 11:48:51 PM
M42 does not have a cold start injecter
02 Sensor was replaced 2 x
AFM rueled out with a swap
ICV worked well when I put 12volts to it
Title: Cold start engine shakes and sputters
Post by: bearsbmw on November 14, 2008, 11:50:46 PM
Quote from: AcSchnitzer318is;60768
This problem is driving tons of us up a wall.  Get used to it... I've been dealing with it now for a year +.  ;)


nevermind about the knock sensors ... e30 m42 does not have my bad
Title: Cold start engine shakes and sputters
Post by: roundel318 on November 14, 2008, 11:56:06 PM
How long does it run with your AFM disconnected before you shut it down, reconnect it and start it back up?
Title: Cold start engine shakes and sputters
Post by: bearsbmw on November 14, 2008, 11:58:18 PM
5mins and hovering at 2000rpm ... I plug it back in while the car is runing and she drop's and idles perfectly
Title: Cold start engine shakes and sputters
Post by: roundel318 on November 14, 2008, 11:59:18 PM
Do you have a spare ECU? Tried reseating the connector?
Title: Cold start engine shakes and sputters
Post by: bearsbmw on November 15, 2008, 12:01:05 AM
reseting the connector ?? if you mean the ECU/dme then yes a million times with a battery unhook over night
Title: Cold start engine shakes and sputters
Post by: roundel318 on November 15, 2008, 12:03:06 AM
Hot plugging anything that feeds to the ECU is a BAD idea.....
Just tossing that out there....
Title: Cold start engine shakes and sputters
Post by: roundel318 on November 15, 2008, 12:04:00 AM
Can you run down a spare?
They go for as little as $40 on ebay.
Title: Cold start engine shakes and sputters
Post by: bearsbmw on November 15, 2008, 12:11:54 AM
Quote from: roundel318;60779
Can you run down a spare?
They go for as little as $40 on ebay.


I guess that will be my next step ... would a grounding out signal wire from the O2 sensor mess thing's up? I remember way back when I was installing my wide band guage I touched the signal on the frame inside the car and it stalled the car but it started back up fine
Title: Cold start engine shakes and sputters
Post by: tjts1 on November 15, 2008, 02:05:01 AM
Check the thin vac hose connecting the fuel pressure regulator to the throttle body. If the FPR is leaking or not receiving vacuum, the car will run like crap in open loop.
Title: Cold start engine shakes and sputters
Post by: bearsbmw on November 15, 2008, 09:55:25 AM
can everyone please post all the item's they replaced when trying to fix this problem

Me=

AFM
02 sensor
Coolant Temp Sensor
Spark plugs
Intake gaskets
Alternator
fuel filter
Relays
Fuses
battery
Title: diag notes
Post by: roundel318 on November 15, 2008, 10:38:49 AM
Since I have a good running car, I decided to play around with it this morning during cold start (it was 35.F out this morning).

I disconnected the AFM, cranked once and turned over a few times sputtering trying to start. Cranked again and fired right up to 1200rpm ish hovering smooth.
Shut off car.

Disconnected ICV AND left AFM disconnected.
Started up and idled low ~500-600rpm, vibration is pretty bad, not sure if this is what you are seeing.

Reconnected everything, started back up, ran for 5 seconds around 2000rpm then dropped and almost stalled but my ICV IS dirty so it was a little slow to catch it. Engine returned to normal idle, 700rpm.

Is yours dirty? What if you disconnect the ICV when you start up?

I don't have this problem so I am just providing some perspective :confused:
Title: Cold start engine shakes and sputters
Post by: bearsbmw on November 15, 2008, 11:45:33 AM
Im going to try and disconnect the ICV and note what happens .. good idea ! but yes I have had it out for cleaning a few times & I tested 12 volts on it and it opened fine
Title: notes
Post by: roundel318 on November 15, 2008, 11:56:07 AM
I wish I was a little more familiar with how M1.7 runs, its also worth paying attention to any fuel delivery related issues. There is a prestart pump that primes the system before startup, then the main pump that runs when the engine starts up.
You can hear the prestart pump prime for about 1/2 second when you turn the key to on.
Do you hear this taking place?

Do you own a Bentley manual for this vehicle?
I found a used working ICV off ebay for $20 shipped.
If this goes on and on with so many people, I could even ship you my spare ECU (factory chip) and spare ICV for a week or something if finding good working used parts is out of the question for you.
Just thinking out loud......again
Title: Cold start engine shakes and sputters
Post by: B318M42W on November 15, 2008, 12:36:47 PM
crazy ideas... we know that the problem is during the open loop mode of the ECU... and then the engine is cold. also, the vent from the crankcase goes back into the intake boot, loaded with oil vapor. maybe a vacuum line is obstructed by oil gunk??? and by the time it "warms up", the oil inside heated up and permits "normal" airflow.. (maybe jammed the FPR also???) and just out of curiosity, how many ppl with that problem changed the fuel pump (or strainer), fuel filter, injectors and FPR. and also checking if the return fuel line isn't clogged.

maybe it could be as stupid as a bad wire from a sensor????
just throwing it out there...
Title: ideas
Post by: roundel318 on November 15, 2008, 12:45:29 PM
I was thinking wiring too, but it seems to run correctly he says.
Of course with car wiring anything is possible:)
He says he hot plugged his AFM after it was running with it disconnected.
Hot plugging anything ECU related cannot be good.
Curious what happens when he starts it with no ICV connection.
Can someone explain more about the ECU open loop mode?
I am always down to learn something :)
Title: Cold start engine shakes and sputters
Post by: bearsbmw on November 15, 2008, 12:52:57 PM
ICV disconnect finding are =

disconnected ICV = clean cold idle but holding at 1200rpm untill the coolant temp get's past the blue it will start bouncing the idle

Disconnected ICV & Afm = rough idle with bouncing idle

AFM only dissconect  yields a high idle hold at 2000rpm
Title: ideas
Post by: roundel318 on November 15, 2008, 12:56:09 PM
When it starts bouncing, what rpm range? how fast does it bounce?
Title: Cold start engine shakes and sputters
Post by: bearsbmw on November 15, 2008, 12:57:49 PM
Quote from: roundel318;60810
When it starts bouncing, what rpm range? how fast does it bounce?


1200 range and up and down fairly quickly but only a few hundred rpm
Title: ideas
Post by: roundel318 on November 15, 2008, 01:00:52 PM
go drive around with the ICV disconnected and after the engine has warmed up some more, does the idle behaviour change?
Title: Cold start engine shakes and sputters
Post by: bearsbmw on November 15, 2008, 01:05:01 PM
ok I will try that ... Does anybody know if the stock ecu chip is maped for startup or does the ECU board have that built in? .
Title: Cold start engine shakes and sputters
Post by: bearsbmw on November 15, 2008, 01:15:59 PM
Quote from: roundel318;60812
go drive around with the ICV disconnected and after the engine has warmed up some more, does the idle behaviour change?


Did that and got normal driving conditions but when I come to stop the idle is holding at 1200 and jumping to 1500 up and down quickly and the fuel usage meter is going wacko!
Title: ideas
Post by: roundel318 on November 15, 2008, 01:27:11 PM
I did the same, driving around and had a 1200rpm idle, with no flux.
Something is going on outside of your AFM or ICV.
I am curious because I am not 100% if the fuel usage meter is vacuum based or if its based off the ECU. I think you need to find a spare ECU to try out.
How is fuel delivery at WOT?
Title: Cold start engine shakes and sputters
Post by: bearsbmw on November 15, 2008, 01:27:57 PM
I should mention that sometimes I get a CEL when at idle for a while throwing 1222 and Airfuel mix is holding rich... I also get this when Im cruising and if I push the gas it go's as quickly as it came
Title: Cold start engine shakes and sputters
Post by: B318M42W on November 15, 2008, 01:32:39 PM
The ECU will throw you a mixture code if the mixture is unchanged for 10 seconds. as soon as there's a variation, it'll go away but reappear.
Title: ideas
Post by: roundel318 on November 15, 2008, 01:32:57 PM
Interesting, do you have a reset tool?
I had one get logged in mine a while back, even though the engine was running fine. Got it reset and it has not returned. Would be interesting to see if yours comes back.
1222 is Primary O2 sensor lean/rich for more than 10 seconds.
Did you test your voltage regulator? (probably doesnt matter)
Title: Cold start engine shakes and sputters
Post by: bearsbmw on November 15, 2008, 01:38:16 PM
reset it lotz of time's .. Voltage regulator is new and built into the new alternator ... system is charging at 14 volt's
Title: ideas
Post by: roundel318 on November 15, 2008, 01:39:11 PM
just past the AFM, the large rubber air boot has a rubber hose with a 90 degree joint that leads down to the medusa.
The joint that leads to down there has a juntion that connects that, a hose coming from the ICV into the rest of the engine / intake manifold (wherever it goes, not sure exactly off the top of my head)
While it sounds like a hose, it probably isnt :)
Just thinking out loud some more :confused:
Title: Cold start engine shakes and sputters
Post by: bearsbmw on November 15, 2008, 01:41:44 PM
presure and smoke test show's zero leaks at 10 psi
Title: Cold start engine shakes and sputters
Post by: roundel318 on November 15, 2008, 01:43:22 PM
I think the next thing to rule out would be the ECU.
I will send my spare to you for a week or two for $5 + you pay shipping both ways.
You break it, etc, you replace it.
I have paypal, btw.
Title: Cold start engine shakes and sputters
Post by: bearsbmw on November 15, 2008, 01:45:33 PM
I can get a ECU here no problem and I also have another chip I can swap into the ECU and see what happens
Title: Cold start engine shakes and sputters
Post by: roundel318 on November 15, 2008, 01:47:20 PM
Nice, it's great to have another spare :)
How is the fuel pressure situation?
Title: Cold start engine shakes and sputters
Post by: bearsbmw on November 15, 2008, 01:52:35 PM
good fuel hit's 90psi when I hit 8psi of boost

I do have a turbo but because my AFM is befor the Intake manifold on the engine and not befor the turbo I can run all these tests in NA condition by just removing a peice of charge pipe and unhooking the rising rate fuel regulator... this is just for the people that are going to say you need a tune and I know its not a tune issue
Title: ideas
Post by: roundel318 on November 15, 2008, 02:33:29 PM
While it would be good to test it N/A style, I have no experience with a turbo on this motor. :confused:
How long would it take you to do this test?
Title: Cold start engine shakes and sputters
Post by: xwill112x on November 15, 2008, 02:47:15 PM
Quote from: bearsbmw;60792
can everyone please post all the item's they replaced when trying to fix this problem

Me=

AFM
02 sensor
Coolant Temp Sensor
Spark plugs
Intake gaskets
Alternator
fuel filter
Relays
Fuses
battery


Me=

plugs
air filter
02
cleaned the throttle body out
fuel pump
fuel injector cleaner
fuses


mine seems to want to run really lean it seems...

seems like something to deal with the air/fuel mixture.. im not to worried, b/c after its warm, it runs fine.
Title: Cold start engine shakes and sputters
Post by: bearsbmw on November 15, 2008, 02:55:43 PM
Quote from: roundel318;60831
While it would be good to test it N/A style, I have no experience with a turbo on this motor. :confused:
How long would it take you to do this test?


All test's have been and while under NA! :)
Title: Cold start engine shakes and sputters
Post by: bearsbmw on November 15, 2008, 02:57:14 PM
Do any of you have realy bad black water spatter shooting from the exhaust? if I put a white sheet a foot away from the exhaust on cold start the sheet will be black in under 2 mins... runing super rich on start up!!
Title: Cold start engine shakes and sputters
Post by: xwill112x on November 15, 2008, 03:09:31 PM
thinking out loud here...

maybe it's not really a problem..but more of something you have to live with...since our cars are getting older..they may not run perfect at start up and it takes the ecu a while to adjust to 14.7:1 due to the o2 giving a good reading until its warm...while as newer cars have more advanced technology and have phased that out?
Title: Cold start engine shakes and sputters
Post by: bearsbmw on November 15, 2008, 03:20:08 PM
Quote from: xwill112x;60838
thinking out loud here...

maybe it's not really a problem..but more of something you have to live with...since our cars are getting older..they may not run perfect at start up and it takes the ecu a while to adjust to 14.7:1 due to the o2 giving a good reading until its warm...while as newer cars have more advanced technology and have phased that out?


I will have to disagree with above due to the fact that this just started happening full out one day insted of coming on slowly and geting worse and worse
Title: ideas
Post by: roundel318 on November 15, 2008, 03:30:11 PM
While doodling around, I disconnected my TPS and experienced similar behaviour, not sure if someone has had a TPS be wonky when cold and work correctly when it starts to warm up?
Probably not likely, but just tossing it out for others to chew over :confused:
Title: Cold start engine shakes and sputters
Post by: roundel318 on November 15, 2008, 03:40:29 PM
Also, when you mentioned Relays, did that include the O2 sensor heater relay?
Title: Cold start engine shakes and sputters
Post by: bearsbmw on November 15, 2008, 03:41:16 PM
Quote from: roundel318;60843
Also, when you mentioned Relays, did that include the O2 sensor heater relay?


swaped working Horn relay for the 02 heater relay

TPS not connected would not let me start my car
Title: Cold start engine shakes and sputters
Post by: roundel318 on November 15, 2008, 03:46:09 PM
and the electrical from the o2 heater relay to the o2 sensor? (darn automotive wiring)
when I disconnected my TPS, my engine starts, barely, and rumbles and vibrates like yours does.
do you know what the "evaporative purge valve" is for?
Title: Cold start engine shakes and sputters
Post by: bearsbmw on November 15, 2008, 03:53:09 PM
Quote from: roundel318;60845
and the electrical from the o2 heater relay to the o2 sensor? (darn automotive wiring)
when I disconnected my TPS, my engine starts, barely, and rumbles and vibrates like yours does.
do you know what the "evaporative purge valve" is for?


Ya that has something to do with the Evap system for the fuel tank I think anyway.. Im prity sure the ECU has no control over this item but I will check bentley for ref
Title: Cold start engine shakes and sputters
Post by: roundel318 on November 15, 2008, 03:56:51 PM
I was checking the factory wiring documentation here....
Bentley manuals rock :)
The ECU seems to have control over the evap purge unit crap, at least from the diagram in this PDF.
the O2 sensor heater works, is its wiring messed up?
Title: Cold start engine shakes and sputters
Post by: bearsbmw on November 15, 2008, 04:00:39 PM
Quote from: bearsbmw;60846
Ya that has something to do with the Evap system for the fuel tank I think anyway.. Im prity sure the ECU has no control over this item but I will check bentley for ref


I take that back Evap valve is controled by ECU
Title: Cold start engine shakes and sputters
Post by: roundel318 on November 15, 2008, 04:03:39 PM
Agreed per my last post, not sure if it is causing the problem.
Beyond a few other ideas we have come up with, I think the most sensible thing would be to try a spare ECU.
Were you running a custom chip right now? did you try the stock one? I think I remember you saying you had a spare / factory chip.
Perhaps I was dreaming :P
Title: Cold start engine shakes and sputters
Post by: bearsbmw on November 15, 2008, 04:06:45 PM
Ok anyone who has this problem ... remove the onboard computer the one in the dash below the cd and unplug it and start car and see what happens
Title: Cold start engine shakes and sputters
Post by: roundel318 on November 15, 2008, 04:08:39 PM
I am just curious, which OBC is this you are referring to?
below the cd?
Title: Cold start engine shakes and sputters
Post by: bearsbmw on November 15, 2008, 04:10:50 PM
The onboard computer below your cd or tape deck.. remove and unplug
Title: Cold start engine shakes and sputters
Post by: roundel318 on November 15, 2008, 04:11:32 PM
Do you have a E30 or E36?
Title: Cold start engine shakes and sputters
Post by: bearsbmw on November 15, 2008, 04:12:10 PM
e36
Title: Cold start engine shakes and sputters
Post by: bearsbmw on November 15, 2008, 04:13:26 PM
sorry on e30s to right
Title: Cold start engine shakes and sputters
Post by: roundel318 on November 15, 2008, 04:14:47 PM
E30 here, my heat / vent controls are below the cd/radio slot.
Is this the normal multi button OBC you are referring to though?
The E36 probably has a 9 or 12 button or thereabouts?
Most M42 E30 cars have a simple OBC that just has a date/time(mem) and external temp sensor (mounted in the brake duct on the drivers side i believe) that does not have so many functions / tie into other systems.
Title: Cold start engine shakes and sputters
Post by: roundel318 on November 15, 2008, 04:16:52 PM
Your OBC probably takes info to calc mileage, range, etc?
It takes info from a host of other systems if so.
What sort of difference are you having with disconnecting yours?
Do you have a grounding problem?
:P
Title: Cold start engine shakes and sputters
Post by: roundel318 on November 15, 2008, 04:18:17 PM
Also, do you have a M42 or M44?
Title: Cold start engine shakes and sputters
Post by: bearsbmw on November 15, 2008, 04:18:18 PM
M42

the signal for the fuel consumption guage has signal going to my 5 button OBC and cluster on my car ... My OBC is currently not working and has been not working since this problem came about
Title: Cold start engine shakes and sputters
Post by: roundel318 on November 15, 2008, 04:19:17 PM
What functions does your OBC have?
Title: Cold start engine shakes and sputters
Post by: bearsbmw on November 15, 2008, 04:20:21 PM
Quote from: roundel318;60861
What functions does your OBC have?


it's the most basic one but acording to the wiring for my car it see's a signal for the fuel consumption guage
Title: Cold start engine shakes and sputters
Post by: xwill112x on November 15, 2008, 04:20:23 PM
e30 318 has date, temp, time, and memo
Title: Cold start engine shakes and sputters
Post by: roundel318 on November 15, 2008, 04:21:06 PM
What happened when you disconnected yours?
Title: Cold start engine shakes and sputters
Post by: bearsbmw on November 15, 2008, 04:22:15 PM
Quote from: roundel318;60864
What happened when you disconnected yours?


Havent dont it yet while the car is cold ... I wan't someone else to give this a try
Title: ideas
Post by: roundel318 on November 15, 2008, 04:23:31 PM
I have started mine up before cold without it connected, car ran fine.
Title: Cold start engine shakes and sputters
Post by: bearsbmw on November 15, 2008, 04:26:58 PM
yes but your obc is not shorting out and working correctly unlike mine ... It could very well be the OBC shorting out and deliverying voltage to the ECU insted of the ecu sending the signal voltage
Title: Cold start engine shakes and sputters
Post by: roundel318 on November 15, 2008, 04:29:02 PM
What year is your car bearsbmw?
The E36 OBC may only have 5 buttons, but it may be either a 11 or 18 function unit.
Just curious exactly what u got?
Title: Cold start engine shakes and sputters
Post by: bearsbmw on November 15, 2008, 04:29:52 PM
last month of 94 m42 Manual
Title: Cold start engine shakes and sputters
Post by: roundel318 on November 15, 2008, 04:31:10 PM
I agree! Indeed, while that is definately a possible cause, you would think it would happen all the time, not just when you start up your car?
Then again, with wiring problems, the sky is the limit :(
Title: Cold start engine shakes and sputters
Post by: bearsbmw on November 15, 2008, 04:34:38 PM
yup this problem is most puzzleing... hope I figure it out soon
Title: Cold start engine shakes and sputters
Post by: roundel318 on November 15, 2008, 04:44:32 PM
Sorry I don't have more experience with E36 OBC wiring, they are more complex than the ones on the E30.
Does your check engine light come on when you start up with it disconnected?
Title: Cold start engine shakes and sputters
Post by: bearsbmw on November 15, 2008, 04:45:38 PM
Quote from: roundel318;60874
Sorry I don't have more experience with E36 OBC wiring, they are more complex than the ones on the E30.
Does your check engine light come on when you start up with it disconnected?


nope  & e30 m42 only has a few minor diffrences from what I can see
Title: Cold start engine shakes and sputters
Post by: roundel318 on November 15, 2008, 04:48:10 PM
I am not sure if this is effected, but since it has individual ignition coils, it may.
Some BMW's with ECU's in the 0 261 200 4xx range could experience strange ECU failure after a coil failure. Mark D offers a service to repair these.

The E30 318's didnt have a complex OBC, they are just basic, although they have lots of wiring going to and fro, the connector has probably under 35 pins.
The 325's had the better one with range, trip, along with the stuff the basic one offered among other things.
E30 318's can be retro-d with one from a 325, although it is tied in with the cruise control, turn stalks, etc and loosely with the active check control (which i believe has all been combined in the E36 OBC) that checks tail lights, coolant level, oil level, abs, srs, backup lights, rear license plate light, etc.
There were two diff OBC's for E36's as well, this was a option from the factory for a 11 or 18 function, or thereabouts.
Title: Cold start engine shakes and sputters
Post by: roundel318 on November 15, 2008, 05:29:34 PM
Or is your OBC like this?
http://cgi.ebay.com/ebaymotors/BMW-e36-seven-button-OBC-Great-condition_W0QQcmdZViewItemQQ_trkparmsZ72Q3a1205Q7c66Q3a2Q7c65Q3a12Q7c39Q3a1Q7c240Q3a1318QQ_trksidZp3286Q2ec0Q2em14QQhashZitem320317340120QQitemZ320317340120QQptZMotorsQ5fCarQ5fTruckQ5fPartsQ5fAccessories (http://cgi.ebay.com/ebaymotors/BMW-e36-seven-button-OBC-Great-condition_W0QQcmdZViewItemQQ_trkparmsZ72Q3a1205Q7c66Q3a2Q7c65Q3a12Q7c39Q3a1Q7c240Q3a1318QQ_trksidZp3286Q2ec0Q2em14QQhashZitem320317340120QQitemZ320317340120QQptZMotorsQ5fCarQ5fTruckQ5fPartsQ5fAccessories)

It seems there were in fact 3 different OBC's available.
Title: Cold start engine shakes and sputters
Post by: bearsbmw on November 15, 2008, 05:41:34 PM
Quote from: roundel318;60879
Or is your OBC like this?
http://cgi.ebay.com/ebaymotors/BMW-e36-seven-button-OBC-Great-condition_W0QQcmdZViewItemQQ_trkparmsZ72Q3a1205Q7c66Q3a2Q7c65Q3a12Q7c39Q3a1Q7c240Q3a1318QQ_trksidZp3286Q2ec0Q2em14QQhashZitem320317340120QQitemZ320317340120QQptZMotorsQ5fCarQ5fTruckQ5fPartsQ5fAccessories (http://cgi.ebay.com/ebaymotors/BMW-e36-seven-button-OBC-Great-condition_W0QQcmdZViewItemQQ_trkparmsZ72Q3a1205Q7c66Q3a2Q7c65Q3a12Q7c39Q3a1Q7c240Q3a1318QQ_trksidZp3286Q2ec0Q2em14QQhashZitem320317340120QQitemZ320317340120QQptZMotorsQ5fCarQ5fTruckQ5fPartsQ5fAccessories)

It seems there were in fact 3 different OBC's available.


yes that is mine
Title: ideas
Post by: roundel318 on November 15, 2008, 05:56:48 PM
You would think if the MPG guage on the cluster works with the OBC, if the engine runs wonky even when the mpg guage is working correctly, you would think it would be something else. however if it was damanged from previous wiring problems, shorts, etc, we come back to the ECU.
Hope swapping that helps ?
Title: Cold start engine shakes and sputters
Post by: bearsbmw on November 15, 2008, 05:59:48 PM
agreed! hopefully a swap will do the trick ... had other's tryed a swap??
Title: Cold start engine shakes and sputters
Post by: KyleTaylor on November 15, 2008, 08:59:19 PM
I am leaning toward replacing my coolant temp sensor that signals the DME.  My gauge works, but on the e30 there is a separate sensor for the DME...  

Mine idles funny and stumbles at first start and if the coolant temp falls below straight up, which is often as the cooling system works well.  When the engine is normal temp it idles like an electric motor... just as smooth after some hard driving at which point the temp may be a little high on the gauge.

I am thinking the coolant temp sensor is not functioning correctly so the DME is in a default mode for normal parameters.

I plan to order and replace the sensor at the beginning of the week barring that no one else has tried this...
Title: coolant temp sensor
Post by: roundel318 on November 15, 2008, 09:10:32 PM
Bearsbmw has that in his list of things he has swapped trying to fix it. (page 1)
If you have a spare, probably worth trying though?
Title: Cold start engine shakes and sputters
Post by: KyleTaylor on November 15, 2008, 09:27:37 PM
darn, I read it all, but overlooked that....  He has replaced everything... wonder why these things want to do this so badly?
Title: Cold start engine shakes and sputters
Post by: tjts1 on November 15, 2008, 09:35:22 PM
Rain or shine, hot or cold, my car never does that. It did when I bought it but not anymore. You guys are taking shots in the dark. Start with the cheapest simplest thing and work your way up, vacuum leaks, spark plug wires, sensors, ICV, injectors...
In that order.
Title: Cold start engine shakes and sputters
Post by: KyleTaylor on November 15, 2008, 09:40:23 PM
As far as I know the only two things that have not been replaced are the injectors and the coolant temp sensor.

For your not in the dark shots what did you do?
Title: Cold start engine shakes and sputters
Post by: bearsbmw on November 15, 2008, 09:42:27 PM
Quote from: tjts1;60908
Rain or shine, hot or cold, my car never does that. It did when I bought it but not anymore. You guys are taking shots in the dark. Start with the cheapest simplest thing and work your way up, vacuum leaks, spark plug wires, sensors, ICV, injectors...
In that order.


those are all thing's that have been looked over if you read abover ^:D
Title: diag notes
Post by: roundel318 on November 15, 2008, 09:46:19 PM
we have been racking up pages of back and fourth just today ;)
Title: Cold start engine shakes and sputters
Post by: bearsbmw on November 15, 2008, 09:52:45 PM
to check for injector leaks just run the car to full temp and then pull the fuel pump fuse and let the car die and let it sit over night and if the engine has a clean idle on next start up then you know its a leaky injector
Title: Cold start engine shakes and sputters
Post by: roundel318 on November 15, 2008, 09:54:31 PM
Good tip!
Title: Cold start engine shakes and sputters
Post by: KyleTaylor on November 15, 2008, 10:18:19 PM
Quote from: bearsbmw;60914
to check for injector leaks just run the car to full temp and then pull the fuel pump fuse and let the car die and let it sit over night and if the engine has a clean idle on next start up then you know its a leaky injector


So that tests whether or not an injector is leaking while the engine is off... never really thought about that... my idle issue is prevalent at more than just startup, though.
Title: Cold start engine shakes and sputters
Post by: roundel318 on November 15, 2008, 10:25:27 PM
its worth testing, seeing it doesnt cost you much.
Title: Cold start engine shakes and sputters
Post by: bearsbmw on November 15, 2008, 10:34:36 PM
Quote from: KyleTaylor;60919
So that tests whether or not an injector is leaking while the engine is off... never really thought about that... my idle issue is prevalent at more than just startup, though.


yes because your fuel system is spose to hold presure untill next startup and and leaky injector would flood the engine causing these symptoms
Title: Cold start engine shakes and sputters
Post by: AcSchnitzer318is on November 15, 2008, 11:36:37 PM
OK I'll play...

1. ICV (replaced)
2. Vacuum Leaks (did TB heater delete and replaced hoses)
3. o2 Sensor (replaced)
4. Plugs & Wires (replaced as part of maintenance)
5. Fuel Injectors (mustang 19#)
6. Exhaust Header Gasket (had a leak)
7. AFM (replaced)
8. Engine Temp Sensor (replaced)
9. Throttle Position Sensor (replaced)
10. ECU swapped (known good unit)

Also had engine smoke tested (no leaks), fuel pressure tested (40-50psi)... no problems.  I am guessing this problem is completely external to the motor.  Reason for this conclusion is that I swapped in a rebuilt motor (20k miles) that didn't exhibit this behavior in the donor car.  Only after being put into this chassis did it start doing this.  The original motor in this chassis did this as well... so something external to the motor is causing this.  Rules out most sensors, vacuum leaks, or timing.  Any other ideas guys?  I was thinking maybe fuel pump... but fuel pressure tested ok.
Title: Cold start engine shakes and sputters
Post by: roundel318 on November 15, 2008, 11:48:03 PM
good food for thought.....
only thing that comes right to mind is a fuel pressure regulator?
Title: Cold start engine shakes and sputters
Post by: bearsbmw on November 15, 2008, 11:55:22 PM
yes I would like to see if anybody has done the regulator because I think these can get stuck in the high presure postion and not leak fuel beyond the diafram

I'm going to redo my ground straps tomorow and open my fuel tank and look inside and look at the fuel pump
Title: Cold start engine shakes and sputters
Post by: roundel318 on November 16, 2008, 12:02:54 AM
We need a song "process of elimination".
It could be a fat breaks track :)
Title: Cold start engine shakes and sputters
Post by: bearsbmw on November 16, 2008, 12:07:25 AM
I love BMW's and all there problems 'Boom De Ah Dah'  'Boom De Ah Dah'  'Boom De Ah Dah'  'Boom De Ah Dah' !!  :D
Title: Cold start engine shakes and sputters
Post by: roundel318 on November 16, 2008, 12:08:49 AM
I am not sure about others, but here is at least one fuel pressure regulator.
Item 6
http://www.realoem.com/bmw/showparts.do?model=AJ93&mospid=47318&btnr=13_0308&hg=13&fg=15
And it seems like it would come and go with an engine swap.
Perhaps there is another on the car somewhere?
Title: Cold start engine shakes and sputters
Post by: bearsbmw on November 16, 2008, 12:15:20 AM
I remember reading somewhere that the e30 has a check valve at the fuel pump that can fail and cause these symptoms

http://www.m42club.com/forums/showthread.php?t=4688
Title: Cold start engine shakes and sputters
Post by: roundel318 on November 16, 2008, 12:20:15 AM
Good call, dig out the rear seat :)
Title: Cold start engine shakes and sputters
Post by: bearsbmw on November 16, 2008, 12:38:43 AM
fuel pressure regulator could very well be the problem
Title: Cold start engine shakes and sputters
Post by: roundel318 on November 16, 2008, 12:46:52 AM
A Bentley manual should have some simple test procedure to check it out?
Title: Cold start engine shakes and sputters
Post by: bearsbmw on November 16, 2008, 01:02:07 AM
No shrader valve on my fuel rail so Im going to remove the regulator and examine it visualy for corosion and rust I will then submerge the regulator in water and put 10psi to it and look for bubbles and then take my sandblasting gun and use the suction hose while under water on the vac nipple and see if the gun picks up water
Title: Cold start engine shakes and sputters
Post by: bearsbmw on November 16, 2008, 09:17:07 AM
update: removed fuel regulator and there was alot of goldish color residue around the orings... I stuck a small screw driver in the middle hole of the regulator and pushed the spring back and forth and it seemed to be sticking and then started spraying wd40 into the housing and worked the plunger with the very small screw driver up and down and it became alot better ... will let everybody know how car starts on cold start soon
Title: ideas
Post by: roundel318 on November 16, 2008, 09:58:31 AM
It's the AN TI CI PA TION

:D
Title: Cold start engine shakes and sputters
Post by: bearsbmw on November 16, 2008, 10:24:19 AM
did not solve the problem
Title: ideas
Post by: roundel318 on November 16, 2008, 11:26:12 AM
Dang, at least we can put it on the list of things that are checked off.
:rolleyes:
Title: Cold start engine shakes and sputters
Post by: bearsbmw on November 16, 2008, 11:46:05 AM
I take it back it was fuel presure regulator all the way!!! GOD DAMN !!

Problem is fixed! thank everyone so much for the imput and help
Title: ideas
Post by: roundel318 on November 16, 2008, 02:15:56 PM
Nice!
We will have to hit up a few others and have them see if they can replicate the fix!
:D
Title: Cold start engine shakes and sputters
Post by: bearsbmw on November 16, 2008, 03:50:43 PM
Quote from: roundel318;60975
Nice!
We will have to hit up a few others and have them see if they can replicate the fix!
:D


I forgot to reset the ecu after I messed around with the regulator and after I did the reset it was like magic!! I suggest everyone take a look at there's and or replace it
Title: Cold start engine shakes and sputters
Post by: roundel318 on November 16, 2008, 05:59:52 PM
So it was the regulator, you resetting the ECU, or both?
Title: Cold start engine shakes and sputters
Post by: bearsbmw on November 16, 2008, 06:58:56 PM
both !
Title: Cold start engine shakes and sputters
Post by: AcSchnitzer318is on November 17, 2008, 11:11:27 PM
How did you get the regulator off the rail?  I was going to replace mine some time ago but gave up after struggling for a half hour or so.  Damnit this could have been fixed months ago.  Oh well at least you found the cultprit in your case.  I hope it fixes mine as well.

I wonder why it only has an effect on initial start?  I'm all excited now...
Title: fuel reg
Post by: roundel318 on November 17, 2008, 11:45:58 PM
It was the one back at the tank, not the one on the engine.
Title: Cold start engine shakes and sputters
Post by: KyleTaylor on November 18, 2008, 12:09:55 AM
So did you do the retro fitted check valve or replace the factory one... which I assume requires a the entire pump...... or what?
Title: Cold start engine shakes and sputters
Post by: roundel318 on November 18, 2008, 12:14:38 AM
Bearsbmw will have to post, I provided the reference car.
Take your back seat out and take a peek.
Title: Cold start engine shakes and sputters
Post by: bearsbmw on November 18, 2008, 12:47:08 AM
On my car it was the one at the fuel rail but on your e30's it is wise to replace the regulator at the rail and the check valve at the fuel pump under the seat and then reset your ecu...for some reason the ecu would not learn that I fixed the regulator and after the reset it worked like the day I got the car... If my 1995 OEM orginal was sticking I can't imagine what your's is doing
Title: Cold start engine shakes and sputters
Post by: AcSchnitzer318is on November 18, 2008, 07:46:31 PM
I bet mine is the one at the tank... since it did it post engine swap... oooohhhh the excitement grows....

Anyone have a realoem diagram of that tank regulator?  I haven't looked under that seat in awhile and want to know what to look for.
Title: Cold start engine shakes and sputters
Post by: bearsbmw on November 18, 2008, 07:56:51 PM
Quote from: AcSchnitzer318is;61174
I bet mine is the one at the tank... since it did it post engine swap... oooohhhh the excitement grows....

Anyone have a realoem diagram of that tank regulator?  I haven't looked under that seat in awhile and want to know what to look for.


Photo taken from another thread on this site

(http://img.photobucket.com/albums/v355/dark_islight/fuelcheckvalveinstalled_2copy.jpg)
Title: Cold start engine shakes and sputters
Post by: JP 91iS on November 18, 2008, 08:06:39 PM
I can't find one on realoem. :confused:

From the "warm start problems" (http://www.m42club.com/forums/showthread.php?t=4688) thread that dark islight posted, it looks like he added a check valve where there was not one previously.

Maybe the E30 fuel pump has a built in mechanism that is supposed to do what the check valve does: retain pressure on the fuel supply lines when the car is off?



EDIT:  ^yeah thats the one I think he added.  I couldn't find a part on realoem with that PN.
Title: check valve
Post by: roundel318 on November 18, 2008, 08:21:30 PM
that is a good conclusion since the system is supposed to maintain pressure while its off.
or a leaking injector, but the engine swap rules that out.