idle problem/sputter...help?

[roriii]

I have a 1990 325is. The car has 46000 miles, and the main problem is that the idle is rough, the car sputters occasionally when pulling away from a stop (especially when the car has been sitting), and it hesitates a little at 4000-5000 rpm. The only modifications are a high flow filter, mark d chip (17-19), 19lb. ford injectors, and a stromung exhaust. The car idled rough from the beginning with the mark d chip and injectors, but seemed to get better after a couple days. A couple weeks later, I noticed that the car was sputtering and hesitating a little when pulling away from idle, I thought it was bad fuel. I had it taken in for alignment and got a valve adjustment and new valve cover gasket the same day. The car came back with even worse, shakey idle and a hesitation in the mid-high rpms as well. A lot of the intake rubber components are new, and the fpr was just replaced. I chekced the voltage on the icv and it was within factory specs. I'm 99% sure its not a vacum leak, I suppose there is a chance I could be wrong though. The chip says 17 on it, but I think there is only one mark d chip for 17-19lb. injectors. I feel like the car is a little rich at idle. Any thoughts? Does it sound like over-sized injectors, faulty software, a vacum leak, a weird valve adjustment, or something else? I've been considering a mchenry chip with m50 pre vanos injectors as an alternative. Thanks for the help
Richard

[jlevie]

I'd smoke test the intake to make sure that there aren't any intake leaks and fix any that are found. If the rough idle persists, I'd next check fuel pressure at the rail and if okay swap back in the 17lb injectors. After that, the CTS of AFM would be my next suspects.

And if it has 100k or more on it, I'd swap the O2 sensor for a new one.

Unless you've significantly increased the mass flow through the engine (think head porting and cams), there's no advantage to be gained from larger injectors. The stock injectors have plenty of head room on a stock engine if the fuel system is operating properly.

[93325]

finally got my e30 and having similar problems but worse....

my car takes at least 10 seconds to turn over before it finally starts up, when i leave it sit for less than 30 minutes it will start fine but after that its a pain. Then when it does start it revs to 3k rpm for another 10 seconds before idle calms down, it still sputters and jumps from 1k to 1.5k rpm. my hosings are tight and no leaks, ive tried cleaning the icv, and that helped but only for a couple hours of driving, any input is appreciated...thanks!

[DMF]

I've had the same issues mentioned by rorii since december and haven't been driving my '87 325is since. My friend and I had diagnosed that i was the headgasket as I have been burning some coolant. I just took it out for a rinse and quick little run and did not see white smoke coming from the exhaust.. but it might just be because of the hot humid weather right now.

I'm going to try and run a compression/leakdown test later today

[E30_fiend]

three letters

A. . .F. . .M

the air flow meter is most definitely the problem with the sputtering. Now your long cranking problem could be a few different things. You fuel filter is dirty, your fuel pressure regulator is clogged or faulty or it could also possibly be you injectors. Did you clean the injectors before installing them?



hope that helps a bit






Taylor

[roriii]

three letters

A. . .F. . .M

the air flow meter is most definitely the problem with the sputtering. Now your long cranking problem could be a few different things. You fuel filter is dirty, your fuel pressure regulator is clogged or faulty or it could also possibly be you injectors. Did you clean the injectors before installing them?



hope that helps a bit






Taylor

I have an m20 afm from a previous e30 that I'm going to try. It seems like with low mileage it shouldn't be bad but maybe it is. I just replaced the FPR and the fuel filter about five hundred miles ago and the injectors were new. I think I might have a cracked distributor cap, or rotor or something. It makes a clanking noise and that would be causing missed sparks, leading to unburned fuel and a rough idle.