PDA

View Full Version : Rough idle/stalling/fuel puddle in intake manifold?



Boone.Msi
10-26-2006, 09:27 PM
To start off i bought my 1995 BMW 530ia from a dealership. they said it had been at the dealership for over a year due to them taking it in as a trade in for too little of a cost.

I bought it in august and it ran perfectly for over a month. then it started to idle rough as it got colder. I then have done the following up untill now:
New Bosch platinum 2 spark plugs
New Bosch OEM o2 sensors
Cleaned Idle control valve with carb cleaner
Cleaned entire MAF
New valve cover gaskets(small puddles of oil)


The car used to only idle rough when i first started it, then it began to idle rough everytime i am stopped for over a minute. It then stalls if i do not put it in neutral and give it gas. it got so bad that i have parked it in my parents garage (i live in an apartment) and let it sit there while i carpool with my friend to work and school.

I finally got enough time to take a better look at it so i started it up and listened. it sounds like not all cylinders are firing a big wobbling chug-a-chug idle. it idles so bad that the lights dim and the serpentine belt squeels a little. i started disasembling the intake manifold to put in my new gaskets and PCV plate, when we took a look through the throttle body and noticed that there is a puddle of fuel inside. It looked almost spotless, no oil or crud just puddles of fuel. im thinking maybe a couple cylinders were flooded with fuel causing it to not run on all 8 cylinders. also the new spark plugs i bought less than a month ago are covered in black. I suspect this is from it running rich.

what should i expect to be replacing now? fuel injectors? or could a sensor have thrown the DME off causing it to run rich? if so what sensors and where should be checked.

please help, ive ran out of money and its hard to commute 30 miles to class and 15 miles to work without my car.

one last thing is that my car will still run if i keep the rpm's above 1000. when i drive, it sounds and feels fine, no powerloss. almost like nothing is wrong, its only when i stop do i have this problem

bmw540
10-26-2006, 11:53 PM
first remove back seat and charge battery.
second when cold check for air leaks using carb cleaner when engine temp is cold.

otherwise check coil resistance.

my gut feeling is the first as mine did the same. solution is to change the alternator bushes and charge rate module. Note I have charged my battery and lasts about 3-4 weeks before it starts again. Have not had any time to fix the alternator.

BillionPa
10-28-2006, 12:12 AM
charge rate module? where the hell is that?


.... anyway, sounds like you have a fuel injector problem. may not be the actual injectors, but the o-rings and clips. they are cheap to fix. your fuel pressure regulator may be toast, so get a fuel pressure test. injectors can get damaged from bad fuel line filters, when were they last changed?

definately check the coil resistance, and if they turn out ok, get new coil to plug boots, as they can go bad and not allow enough current to the plug, which allows unburned fuel to get into the CAT and back into the intake manifold.