Author Topic: I need some Serious $#%@#$in Help seriously (Read 26728 times)

fiftytakedowns · « **on:** February 11, 2011, 01:07:50 AM »

IS there any way to isolate whether this is a Fuel issue, a Spark Issue, or an electrical Issue?

Im planning to attack this in a couple ways this weekend:

Here are some Videos of how it runs:

http://www.youtube.com/watch?v=Eu5npniUyl4

http://www.youtube.com/watch?v=NF3NEp_dnX4

the sensors Checked out pretty good CPS had a like 650 ohm reading while the camshaft sensor was like 1300 ohm.

it's acting like its not getting fuel. Im hoping there isnt some fucked Wiring somewhere. and I added and extra ground between the shock tower and the intake plenum.

Any Ideas?

I am getting two different ECU readings

Of my MARK D chip ECU and its spitting out a 1271 code

off the stock ECU no chip Im getting a 1244 code

the Stock ECU has LESs of a problem than the Mark D one, but it still is pretty bad and NOT driveable.

So I do have a SPARE DME.

and its been even more frustrating now, as I am leaning towards fuel problem now.

I'll be driving, the car will be going fine, and after 30 seconds of driving, it will do agressive sputtering, and nearly impossible to drive. my narrowband gauge is going all over the place, but moving to the lean area. I think... But If I take out the ECU and put it back in, it resets and goes back to normal. until 30 seconds are over.

JoeDellio · « **Reply #1 on:** February 11, 2011, 01:18:08 AM »

As far as I see its somethin electrical man, should be an easy sensor fix. When you let go of the clutch it smooths out just because the engine being under load causes the engine to turn, instead of being forced to turn by combustion.

fiftytakedowns · « **Reply #2 on:** February 11, 2011, 03:14:29 AM »

Quote from: JoeDellio;101348

As far as I see its somethin electrical man, should be an easy sensor fix. When you let go of the clutch it smooths out just because the engine being under load causes the engine to turn, instead of being forced to turn by combustion.

Did some sensor Testing:

Coil 1: WAs Sparatically Changing Ohm Levels:
from .03 to .05
Coil 2: .015
Coil 3: .015
Coil 4: .015

These were the coils Off of a Coil on Plug conversion, not sure if that makes a difference.

AFM:
got a consistent reading between pins 3 & 4 to 3.94V through -.06V
Between pins 1 & 2 : 3.8 V

TPS:
At idle between Pins 1 & 2 4.3V
Full throttle: .96V

Between pins 1 & 3 5v
Between pins 2&3 at Idle .62 V
full throttle: 4.0V

I may have done some testing wrong though, I just sort of stuck in the gauge and read values.

DesktopDave · « **Reply #3 on:** February 11, 2011, 07:51:56 AM »

Double check those coils. If you have one off it'll overheat the DME coil drivers & eventually kill the DME.

COP packs are difficult to test, you may have to take them to a shop for testing. I'd attempt to swap that low resistance one out. DVMotorsports had the same trouble with his, it killed the DME. I'll see if I can find the thread after I get the kids on their school bus.

doitover · « **Reply #4 on:** February 11, 2011, 08:36:53 AM »

That sounds like how fuel pumps die.

fiftytakedowns · « **Reply #5 on:** February 11, 2011, 10:55:18 AM »

How doyou know if the DME is dead, They have been spitting out the same codes for quite a while.

I was wondering if a fuel pressure regulator would have anything to doi with these problems

DesktopDave · « **Reply #6 on:** February 11, 2011, 12:10:38 PM »

If the DME dies the car won't run. The trouble with a bad coil pack is that it won't protect the DME's coil drivers. The pack & the driver work as a team. If the pack dies it will eventually take the driver with it...too much current flows through the DME & cooks the driver. I'm not sure what kind of code this would set, if any.

The coil drivers are just four big transistors mounted in the DME case. If this is what's causing your trouble, even if you pull the dying coil pack & swap a known good one in, the driver is damaged & it won't run right until you replace or repair the DME. Those packs use a lot of juice and the drivers will overheat if the coil resistance is out of spec.

I'd start eliminating problems instead of just guessing. Ask if you can borrow a fuel pressure tester to eliminate that whole system. You could buy one too, HF usually has them for <$20. You don't need a pro unit (as long as it can measure pressure over 50psi), something cheap like this will do:

http://www.harborfreight.com/fuel-injection-pump-tester-92699.html

fiftytakedowns · « **Reply #7 on:** February 11, 2011, 03:16:19 PM »

Good news: its not the coils.
got some new ones, and they didnt change anything.

I put some plug wires in, and then had the coils on separate, and then I disconnected the plugs wires, and there was still spark jumpin between the coil pack and the plug wires.

what Is really odd is how if I disconnect the DME and plug it back in again, the problem goes away temporarily.

DesktopDave · « **Reply #8 on:** February 11, 2011, 04:16:01 PM »

Glad it's not the coils, one thing eliminated. So let me ask a few more questions, I'm not 100% on this one.

Does the problem go away only when the DME is cold?
Both DMEs through different codes?
Did you test the O2 sensor?

Makes me think something is way out of whack when the car leaves open loop (the warm-up & WOT cycles). and switches over to closed-loop (normal running with a warm engine). O2 and temp sensors are the culprit on that one...they both might make the car run really rich but should throw a 1213, 1221 or 1222 code. Coolant temp sensors should throw a 1223, but I've never seen nor heard of that happening.

Your O2 sensor is going all over the place, are you sure it's good?

The other opinion I have is that the DME has a bad coil driver as I've mentioned before...if it's overheating the DME may be going. But if you've been swapping two DMEs and having the same symptoms I'd suspect that's not the case.

fiftytakedowns · « **Reply #9 on:** February 11, 2011, 06:00:15 PM »

Quote from: DesktopDave;101372

Glad it's not the coils, one thing eliminated. So let me ask a few more questions, I'm not 100% on this one.

Does the problem go away only when the DME is cold?
Both DMEs through different codes?
Did you test the O2 sensor?

problem is worse when Car is cold
Dme temperature seems to not matter.
Both DMEs throw different codes.
O2 sensor has less than 10,000 miles on it.
when I plugged in the thing up top (hot start plug) it Seemed to help a little, but then problem would come back

Quote from: DesktopDave;101372

Makes me think something is way out of whack when the car leaves open loop (the warm-up & WOT cycles). and switches over to closed-loop (normal running with a warm engine). O2 and temp sensors are the culprit on that one...they both might make the car run really rich but should throw a 1213, 1221 or 1222 code. Coolant temp sensors should throw a 1223, but I've never seen nor heard of that happening.

the CEL doesnt come on!

Quote from: DesktopDave;101372

Your O2 sensor is going all over the place, are you sure it's good?

It's a narrow band so it only gives a general reading.

Quote from: DesktopDave;101372

The other opinion I have is that the DME has a bad coil driver as I've mentioned before...if it's overheating the DME may be going. But if you've been swapping two DMEs and having the same symptoms I'd suspect that's not the case.

I know it's pretty frustrating
[/QUOTE]

Took it to a mechanic, he wasnt giving full attention, but He heard it.

mechanic says its a misfire, where should I check next?

BTW i unplugged the camshaft sensor and it changed nothin, same synptoms.

DesktopDave · « **Reply #10 on:** February 11, 2011, 07:32:11 PM »

I'm stumped myself. You've been all over that engine. Let me think on it for a while.

fiftytakedowns · « **Reply #11 on:** February 11, 2011, 09:51:34 PM »

Quote from: DesktopDave;101381

I'm stumped myself. You've been all over that engine. Let me think on it for a while.

Thanks man, I appreciate your effort, Im getting really Frustrated, and Not to mention it's parked in front of the GF's house, and they want it out!

Once I finish the e30 I can go back to working on my Turbo 2002 which is liek NEARLY done!!

here is the link to my 2002 Turbo Build thread which I will attent to once I finish this e30

http://www.bmw2002faq.com/component/option,com_forum/Itemid,50/page,viewtopic/t,346632/highlight,/

pdxmotorhead · « **Reply #12 on:** February 11, 2011, 09:58:07 PM »

Fuel pressure gauge would tell if its the pump.

I've seen fuel filter cause this exact problem and no matter how new they are it only takes 1 tank of bad gas to wipe one out....

Make sure your head has a ground strap to a good earth. COP kits need good circuits on the ground side to function correctly. The new non metal head gaskets prevent good electrical contact to the block sometimes.

How old are the injectors? THey can get sticky when hot and grungy.

Good Luck

Dave

fiftytakedowns · « **Reply #13 on:** February 12, 2011, 01:35:33 AM »

Quote from: pdxmotorhead;101386

Fuel pressure gauge would tell if its the pump.

I've seen fuel filter cause this exact problem and no matter how new they are it only takes 1 tank of bad gas to wipe one out....

Make sure your head has a ground strap to a good earth. COP kits need good circuits on the ground side to function correctly. The new non metal head gaskets prevent good electrical contact to the block sometimes.

How old are the injectors? THey can get sticky when hot and grungy.

Good Luck

Dave

I was getting a consistent 45 PSI at one of the fuel lines and 55 if I disconnect the FPR . I only tested one, but I figured the return line wouldnt have 45 PSI anyway.

I replaced the ground strap that goes from the Frame to the like engine mount arm thing. I have another ground strap that I attached from the shock tower to the intake throttle body( I figured it would get to the head?). There Is a third ground wire that appears to be coming from the Firewall where the battery would be, and it's grounded at a spot right there (clean contact)

I have a spare stock set of injectors, if all else fails I'll swap them in. as well as the TPS that is on that spare throttle body.

Is it possible that the coils are grounding out to the COP bracket? I cant quitte understand why its throwing a COIL #1 code in one of the DME's and the other DME is throwing a Camshaft Sensor Code.

I also did a smoke test and found NO vacuum leaks or any smoke protruding.

The car did sit for about a month while I did the Timing chain job.I just filled up the tank yesterday. But what Is extremely weird Is why would the problem go away temporarily If I unplug the DME and plug it back in again?

pdxmotorhead · « **Reply #14 on:** February 12, 2011, 01:59:17 PM »

When you unplug the DME it resets to a standard map, then as the engine runs it attempts to compensate for what it perceives as the optimum settings.

The newer pump gas SUCKs for storage, If the tank was below 1/2 its very possible the fuel went bad. The fuel should have a light sharp smell not a heavy varnish smell, often the exhaust will smell real odd if the fuel is dodgy...

It sounds absolutely crazy but If the head itself is not really grounded directly to the battery neg You can have weird ground paths in the motor. I've had a handfull of race cars where 2" of ground strap grounding the head to the block has fixed weird ignition problems, as well as bad DME grounds... Its the reason the rice tuners have the ground spiders under the hood of their turbo cars, makes up for the shoddy factory wiring...

You could also have a thermal issue as someone pointed out, crank sensor or cam sensor that is freeking out when warm. probably tests good when cold.

Good Luck.

Dave