idle issue. Kind of odd one. 318is m42

[rallyegolf]

I dont drive the car much, and when I started it up the other day, it had a rough start. No big deal, I ran it and it cleared up.

Today on the way to work I pull up to a stop light and it sputters, shakes and dies. I tried to start it and it would fire up, but then die again. In a panic to get out of the intersection, I turned it over, gave it some gas, and it runs fine.

I continued to work, and pulled into my parking spot where I let it idle, and every 5 or so seconds, my MPG gauge shoots all the way up and the rpm's drop. The car almost dies at that point, then corrects itself. In another 5 seconds it does it again.

Ohh and when the car is cruising down the road, I have no problems at all.

maybe a bad injector? maybe a vaccume leak?

I guess I need a list of things to check so I can solve this issue. Thanks for any suggestions in advance.

[James Crivellone]

I'd start checking that rats nest under the upper intake manifold and see what you find.. I fixed 99% of my roomates idle issues on his M42 just by replacing a few cracked hoses under there.

[rallyegolf]

I started reading some old posts and I think that is what I will do after work today. I may eliminate all that crap and see if that helps. anyone have a good post on the removal of all that crap?

[Teaguer]

Yeah I second the maze of vacuum lines under the intake .

Check out m42club.com for a few threads on eliminating that crap, if you are feeling adventurous go ahead and eliminate the throttle body heater set-up while you are at it .

[rallyegolf]

Well a little update:

I decided to take the car home on my lunch break and just ride my Motorcycle back to work. I got all the way into my garage, and it died again. There was a whole lot of shaking and clunking around, and now it will turn over but not start. I think something internally is out of wak. I did have time to look at the hoses under the intake manifold and everything looked pretty good.

How can I test spark on a motor that wont start? Also I need to get my hands on a repair guide. What is the best one out there?

thanks

[rallyegolf]

New update:

I got home from work and tried to turn it over to see what was going on and when i try to turn it over it goes.
turn,turn,turn,turn,turn,turn,turn,turn,turn, clunk
I think my motor is jacked. i am going to have to pull off the timing cover and see whats going on in there first. What a pain in the ass.
if anyone is looking for a deal on a clean non-running 318is. let me know.

[RedHoodRidah]

Alot of crank but no start threads lately. If you look at a few of the other threads for the crank but no start issue you should look into them. Did you check fuel pressure?

Did you have a loud fuel pump prior to this issue starting? It can be a few other things.

[gearheadE30]

I think your engine is probably fine. As a wild guess without seeing the car it might be crank or cam sensor, a bad ground, something shorted in the injector harness, etc. If the MPG gauge is moving, it is injector related. To check for spark, pull the leads off one at a time and use a spare spark plug. You will be able to see the spark when the motor is cranked. Be very very verrrryyyy careful with this though; that is pretty high-voltage stuff.

[rallyegolf]

I think your engine is probably fine. As a wild guess without seeing the car it might be crank or cam sensor, a bad ground, something shorted in the injector harness, etc. If the MPG gauge is moving, it is injector related. To check for spark, pull the leads off one at a time and use a spare spark plug. You will be able to see the spark when the motor is cranked. Be very very verrrryyyy careful with this though; that is pretty high-voltage stuff.

This makes me feel a little better about it. I really didn't want to tear down the motor. I will go through the electrical and see if I can find the problem.

thanks again.

[rallyegolf]

Dang, those sensors are kind of pricey.