::HELP PLEASE:: 316i warm idling issues

Post Mon Jan 28, 2013 6:33 pm

Hello all

This is my first forum post ever so please forgive me if i am doing it wrong.

I have a 1994 BMW 316i Touring and i am having idling issues once the engine has warmed.

I start the engine cold and it runs fine for 2 or 3 Mins then it starts running really rough and dies when the given any throttle.

You can rev through it past 2000 rpm and from there up it seems to run fine.

I have been trying to find the problem methodically and i have replaced the whole distributed, plugs, HT leads, and the blue coolant sensor/sender as i have read these can be problematic and cause such behavior. But none of these seemed to be the problem as it is as bad as ever.

I was wondering if any of you guys could help please and advise or if any of you have had the same problem.

Many thanks in advance

Ant

Post Mon Jan 28, 2013 7:50 pm

How long have you had the car? Has it always behaved this way, does it improve when it's up to the normal op temp (about midway on the gauge)?

So does it misfire/stutter before 2000rpm, does it not do this at all before 2/3 minutes?

Post Mon Jan 28, 2013 8:50 pm

Hello i have had the car for well over a year now. It has never done anything like this before. This problem has only occurred in the past two days.

Its runs normally and smooth during the 2-3 mins and then starts to run lumpy. It seems like it is running lean.

it stutters untill you have managed to work the throttle past 2000RPM and its fine there on up. i managed to drive it home not letting the revs drop below that. but as soon as the revs dropped below 2000 it died when the accelerating and nearly stalling.

Cheers. any advice is welcome.

Post Mon Jan 28, 2013 11:13 pm

After removing the ICV and giving it a good clean out with brake cleaner. i stated and ran the car for a while. i started and left it at tick over a few times.

I read somewhere that the ECU needed time to learn and adjust the reading from the new senser so i thought id try it. and it progresivly got better and it now seems to be running fine.

i think it was the coolant temp sender that was faulty. bably never been changed and its on185K

Post Tue Jan 29, 2013 7:51 am

Great, so did you change the temp sensor and clean the ICV?

Good news!

Post Tue Jan 29, 2013 12:51 pm

I have replaced the coolant temperature sender (blue one) and cleaned the IVC.

after testing the sensor i now know that it wasnt even faulty.

i also forgot to mention that i have ?reset? the ECU by disconecting the battery for about an hour.

The problem seems to have gone away for now. I have no idea how tho.

Any ideas what else it could be? faulty ECU? anything to do with the fuel?

Post Tue Jan 29, 2013 12:57 pm

It sounds like it was justthe ICV...keep us posted if it rears it's head again!

Post Tue Jan 29, 2013 9:01 pm

i will do. cheers man

Post Mon Feb 11, 2013 10:50 pm

Hello again, The problem arose again.

pulling out of a very dodgy T junction the car decided to cough and splutter and crawl forward putting me in the middle of a main road with a car the refused to move. could of died if there were actualy any cars around and it was 12.30 lastnight

any way. last time i fixed this i swapped out almost every ancilery and finaly when i reset the ECU and cleaned out the ICV bingo it worked fine and idled better than ever.

this time i went straight for the ECU and left it disconected for 30 mins and then we were running fine again.

does anyone know exactly what could be wrong here? whats causing the fault or have i just got a dodgy ECU? when i bought the car just over a year ago i fitted a good 2nd hand one because the original had poped a chip and burnt out. could this be linked?

thanks for any replys guys

Post Tue Feb 12, 2013 6:11 am

You replaced the blue temp sensor but did you test the wiring by doing a continuity check to the ECU pins? If there's a break in the wire then the car will run rich from cold, leading to flooding after 2-3 mins

Post Tue Feb 12, 2013 8:49 am

Grrrmachine wrote:You replaced the blue temp sensor but did you test the wiring by doing a continuity check to the ECU pins? If there's a break in the wire then the car will run rich from cold, leading to flooding after 2-3 mins

I Have not, i will give this a go tonight.
i have found a diagram showing me which pins to test.

When i replaced the blue plug i did check the wires on the plug for cracking and wear visualy as ive read they can fail there.

Cheers