Author Topic: Rough Start (Read 5126 times)

EN318isPDX · « **on:** October 16, 2007, 01:00:46 PM »

Where in the world is the cold start on the M42? Is there even one? When i start up the car its rough about 50% of them time. Warm or Cold! (makes me think idle control) It seems if i rev it, it starts to go away but sometimes it will just shut me off from giving fuel to the engine.. foot to the floor i get less than idle then the car dies! Half the time when i rev it the problems goes away and i can drive away no problem, i can restart the car and it seems to be ok.

vitesse · « **Reply #1 on:** October 16, 2007, 01:26:43 PM »

No cold start valve on the 42s. Idle control valve is only working when the car is idling, once you give it gas that system turns off. Could be the Throttle position sensor, possibly the air flow meter.

EN318isPDX · « **Reply #2 on:** October 16, 2007, 02:02:05 PM »

Quote from: vitesse;35840

No cold start valve on the 42s. Idle control valve is only working when the car is idling, once you give it gas that system turns off. Could be the Throttle position sensor, possibly the air flow meter.

Throttle position will be next to be replaced but i am missing a clip on the thottle cable (doubt thats it). Dont understand why it would only happen when i first start out and not ever again until i shut the car off and it doesn't always happen after i start it up again.

AcSchnitzer318is · « **Reply #3 on:** February 01, 2008, 12:30:17 PM »

I have this exact issue. I thought it was related to the cams I'm running though. I just recently bought a 91 318is with a blown head gasket. So I replaced the motor with a VERY low mileage motor that had regrind cams (schrick specs). I have start issues exactly as described above for about 2-3 minutes then all is fine and dandy. Engine temp has no effect on the problem, just turning off the ignition and leaving it for more than a couple of minutes will trigger it.

I thought I needed a custom chip for the car to fix the issue, but maybe the problem is something else. Any help would be awesome, it's kind of annoying having to wait for the car to start idling properly before driving.

Nomadic · « **Reply #4 on:** February 08, 2008, 02:37:46 AM »

Could be a long-shot... but I've heard that a fuel pump on its way out can cause starting/ intial idle problems. Can anyone confirm this? I'd consider putting a fuel pressure gauge on it if you run out of options...

Ruger · « **Reply #5 on:** February 11, 2008, 09:09:17 AM »

I had this problem
Cold start it was difficult to start and when it did i had to sit and let it idle for at least 30 seconds before i moved off.
If the car was warm, switch it on and it would start missing and idling rough for a while, a bit of throttle and the revs drop and the car hesitates. Foot to the floor it would stutter but eventually bring up rpm....

turned out to be o2 sensor.

DRtothE · « **Reply #6 on:** March 17, 2008, 04:32:17 AM »

Quote from: EN318isPDX;35837

Where in the world is the cold start on the M42? Is there even one? When i start up the car its rough about 50% of them time. Warm or Cold! (makes me think idle control) It seems if i rev it, it starts to go away but sometimes it will just shut me off from giving fuel to the engine.. foot to the floor i get less than idle then the car dies! Half the time when i rev it the problems goes away and i can drive away no problem, i can restart the car and it seems to be ok.

I would check the fuse box, make sure i didn't have a short between the fuse and the fuel pump, and i'd get under that back seat and make sure my pump is pumping :cool:. When i bought my 318is somone had used a hydraulic lift underneath my gas tank and obliterated my pump. I'm not mentioning any names but (John's Auto Sales‎ - 5001 S Westshore Blvd, Tampa, FL)