Author Topic: New Car: BIG cold start problems (Read 27358 times)

92BMW318is · « **Reply #60 on:** December 23, 2009, 07:18:33 AM »

you can spray carb cleaner on your hoses to test for vacum leaks if there is a leak then your car will rev up, but

i bet its somthing simple, my engine was bogging and sputtering because i accidently mixed up 2 spark wires, took me 4 days to figure out thats what did it and before i figured it out i ended up replacing like 6 diffrent parts ha...

fiftytakedowns · « **Reply #61 on:** December 23, 2009, 08:11:24 PM »

I'll try swapping the 4, and 1 coils, see if that does it.

What confuses me is that It runs perfect when warm though..

fiftytakedowns · « **Reply #62 on:** December 24, 2009, 02:24:54 PM »

NOT the Idle control Valve. just tested, and have a good working one.

timc1018 · « **Reply #63 on:** December 24, 2009, 10:23:57 PM »

hey guys, same problem here (I FEEL YOUR PAIN!!! IT SUCKS!!). engine boggs is sluggish and unresponsive when outside temp is 60F or below and until the temp needle is out of the blue, although it idles on it's own alright unless its in the 40s outside, but even then it holds it's own. all my resources (mostly you guys) have led us to believe its the AFM, however the O2 sensor and coilpacks seem like a high possibility. We've gone through the same motions as well, replaced all the coolant hoses, coolant temp sensors, camshaft pos sensor, intake bellows. TPS seems to be working as per multimeter specs, and ICV killed engine when we unplugged it (although no audible 'buzzing'), so it's assumed that it's working as well. Haven't tried testing the AFM (trying to find one that won't break the bank) or seeing if the O2 sensor is too bad to work. Have you tried those fifty?

fiftytakedowns · « **Reply #64 on:** December 25, 2009, 12:55:57 AM »

My AFM's are good.
No idea on the 02 sensor

my thoughts are:
-bad comp/ grounding wire in harness. (I have two computers I have been using to test)
-Vacuum leak that is out of intake area.
-crank position sensor
-02 sensor

today I really really really serached for a vacuum leak. and I have all the symptoms but no dice. I went with propane, Brake clean, carb cleaner to try and find some problem. The car putters when it is idling, then comes out, smooths, then putters for about 5 secs on 5 secs off. Otherwise it bogs agressively, at 1.5K rpm until warm and misfires, hesitates at 3.5k when almost warm, and nothing when completely warm.

fiftytakedowns · « **Reply #65 on:** December 27, 2009, 09:38:26 PM »

It seems as if when the car is bogging the Fuel is completely shutting off, or the spark is completely stopping.

car makes popping/ minor backfire noises if I hold throttle open when it is bogging down.

fiftytakedowns · « **Reply #66 on:** December 28, 2009, 10:40:35 PM »

LEts assume I just encountered this problem, What series of tests would you conduct to try and pinpoint the problem, being fuel, or spark related?

worst comes to worst I may put in a resistor in the coolant temp sensor.

fiftytakedowns · « **Reply #67 on:** January 05, 2010, 03:32:43 PM »

not sure if this helps, but SOMETIMES if it starts bogging down, and I floor it, the car Violently jerks between bogging, and actual ignition, like Sputtering of working and non-working.

richbarn2 · « **Reply #68 on:** January 05, 2010, 04:35:42 PM »

Have you taken a really, really good look at your intake bellows yet. I see you have been fighting this for almost a year. If there are any cracks at all it will cause similar symptoms. 30 bucks for a new one to remove it from the suspect list, unless you have already done so.

I bought an AFM after my codes were read only to find a crack in my bellows, which was in fact the root of the problem.

Only trying to help, if you already replaced it or are 100% sure yours is good disregard my post.

fiftytakedowns · « **Reply #69 on:** January 05, 2010, 07:46:20 PM »

Quote from: richbarn2;84087

Have you taken a really, really good look at your intake bellows yet. I see you have been fighting this for almost a year. If there are any cracks at all it will cause similar symptoms. 30 bucks for a new one to remove it from the suspect list, unless you have already done so.

I bought an AFM after my codes were read only to find a crack in my bellows, which was in fact the root of the problem.

Only trying to help, if you already replaced it or are 100% sure yours is good disregard my post.

I took it out, and examined it very carefully. no internal cracks at all. There was a minor crack on the top(outside), which I put carb cleaner on, and testing to see if it went through, with water, etc.. sprayed while running, sprayed all over. no change. Thats what I did to take it off the list.

Still dont know if my TPS is within specs with 1.9-5v range, and my cps testing at 512 ohms.

raisbeck · « **Reply #70 on:** January 10, 2010, 04:32:39 PM »

I've been dealing with the same problem for a little over a year. Normally, it doesn't take more than a couple of minutes to get the car warm enough that the problem goes away, but it is aggravating.

I won't go into the list of things that I've tried, unless someone wants me to, but...

Did you ever get it to work? How?

DesktopDave · « **Reply #71 on:** January 10, 2010, 05:45:59 PM »

I'm still wondering too. Here's some hunches:

I'll bet the Dinan has a bad transistor on the coil circuit that's flagging the error. I'm thinking that the AFM temp sensor (not the mixture flap) might be a culprit too, or the O2 heater isn't functional. Those both can modify the mixture in more for open loop warm running but not so much when the engine is fully warmed up in closed loop.

fiftytakedowns · « **Reply #72 on:** January 10, 2010, 08:22:03 PM »

Today i tried flooring it when it was bogging, and it seemed to be able to maintain a speed, but with violent jerks of ACtual igniting. like someone was turning on and off the spark/fuel

fiftytakedowns · « **Reply #73 on:** January 10, 2010, 08:22:55 PM »

Quote from: DesktopDave;84363

I'm still wondering too. Here's some hunches:

I'll bet the Dinan has a bad transistor on the coil circuit that's flagging the error. I'm thinking that the AFM temp sensor (not the mixture flap) might be a culprit too, or the O2 heater isn't functional. Those both can modify the mixture in more for open loop warm running but not so much when the engine is fully warmed up in closed loop.

can you replace the afm temp sensor?
hmmm, what do you think I should do then/ how should I tackle this.

DesktopDave · « **Reply #74 on:** January 10, 2010, 08:59:16 PM »

The sensor can be tested, let me see if I can find that somewhere. I should really print up a copy of the manual to have on hand for reference.

I'll bet the thermistor can be replaced too, likely it's a $5 part at DigiKey or a domestic cross-ref exists. I'd like to remove mine...it's right in the middle of the airflow into the engine & I'll bet it impedes flow.