Car starts fine then stumbles and dies

[BlackE30]

Hey guys

I have posted about this before but still have not figured out what the cause is....

I have a 97m3 engine with obd1 swapped into my e30. I purchased the car with the swap done two years ago but have yet to figure out why my car has starting issues "only sometimes."

Usually when the car has been running for a bit, then turned off for 5-20 minutes(could be less could be more) or so- when I got to start it, it fires right up but then stumbles and dies within about 5 seconds. if I startit again right after it starts up and idles/runs fine.

What could be causing this?

I cant find any vacuum leaks and the only thing I feel like I havent replaced is the FPR. Usually the FPR though will make it hard to start which is not the case.

It was throwing a code for the MAF last week, I replaced it and it continued to show the code but has since gone away. It now is showing a code for the o2 sensor as of this morning. It could have been that I was messing with the intake side and it went to a lean/rich condition when I pulled a vacuum line though.

Any help would be great.

Jeff

[Mako18]

Deff not the O2. My car ran fine without one at all for a short period of time.

When you replaced the maf was it installed correctly? it happens.

ICV could be the problem? Does it idle at all? I would also check all grounds make sure they have a good connection. Check the c101 for corrosion or bad connections.

[e30s50dan]

fuel ?!

[MattM]

im betting a fuel issue, either pump, or an air leak somewhere.

[BlackE30]

But why would it start fine when cold if it were one of those issues?

To make it clear- the car has no problems when cruising around, this issue is only when I try to hot start and will be fine after the second hot start.

I just checked for vacuum issues, found none. Also checked all of my injectors to see if they were leaking, nothing.

Car has a fuel filter with less than 3k on it.

What should I check now?

Mako - the car has been doing this for 2 years, I've never been able to find the problem.

[BlackE30]

Just captured this event on camera for you to see. Nothing special but maybe someone will notice something.

http://www.youtube.com/watch?v=YFf0yZ5V8a0

[lennon]

maybe its all those loose wires

[416stroker]

maybe its all those loose wires

+1Your haness is a joke. Id start there

[BlackE30]

I had to move everything to get to one of the vacuum lines that I was working on earlier, the harness is fine and is usually concealed in an m3 cover.

Car uses the treehouse racing adapter.

Jeff

[lennon]

i was just kidding, no clue why it died.

check fuel pressure/watch it before the motor dies?

[416stroker]

I dont think it would be fuel related he should have a hesitation when underload some place in the powerband. have you tried a differnt DME. have you cleared the codes?

[lennon]

yea i was thinking he should try another ecu too. youre right it probably isnt the fuel if its only at startup/idle and only sometimes. its just one thing to clear up/know whats going on.

[lennon]

man the more i watch that video the nastier that sounds haha

[BlackE30]

Here's something interesting- I dont know if its a fluke or not. The last two times I have had the car scanned at the bimmer shop, the car would have the hot start issue but would save itself before it died. I dont know why that happened? Last time it got scanned they said nothing was there so I had no codes and yet the car saved itself anyways?


I do want to try another DME but havent gotten around to it yet. Was hoping I could borrow someones locally instead of having to shell out 100+ to buy another one. I guess its time to man up and get one.

Thanks for the advice.

[lennon]

no, find someone local to let you try their DME in your car. its not worth buying one when you dont even know thats the problem. theres gotta be an m3 around.