Hi, hope someone can help me with some more ideas. I have a MY95 UK car with a strange problem. When starting the car from cold the revs are initially at about 500, then after 4-5 secs they increase to norm 1400. if you press the throttle before the revs have risen the car will cough and almost stall, feels like it's running lean to drive until it's warmed up a little i.e. hesitant at low revs when throttle is applied. Ive checked everything, no fault codes, temp sensor 3k when cold 300 ohm when warm, MAF 1.4v cold 0.97v warm (idle). it's not dependent on air temp either just when the car engine is cold. To add to the problem the car also holds back at around 3500 rpm, just after full boost comes in, not a missfire or hesitation, almost like boost or timing is being pulled. car spec is as follows.

New plugs 0.7mm
New coil packs x 4
Green filter
Dawes at 0.9 BAR
Z4 ECU

problem is there with Z4 or standard ECU fitted and Dawes or boost solenoid connected, the only time i didn't get the car holding back was when i ran in safe mode at 0.5 BAR.

It did the starting problem for a while in late Nov but cured itself, now it's back again, the only thing i have done is switched to tesco 99??

Does anybody have any ideas, or is it time to warm up the plastic friend.
Thanks.

 

BTT for new readers, getting desperate now.

I checked the Idle control valve out tonight, i think there is a problem with the water heated side of it, to get the ECU voltage in limits for idle i'm having to turn the elec solenoid on top all the way to the stops when the car is warm, so i took off the valve to have a look but couldn't see anything in the way of cold start or bi-metalic mechanism, however running boiling water through the pipes for ages didn't add any restriction to the airflow passage so i'm guessing it's knacked. Does anybody think this could cause cold starting problems? although the valve seems to be stuck in the cold start position and not closing down when warm. Idle when warm is stall a perfect 900.

 

same thing happens with mine too!

 

only difference is my fan kicks in before i fire it over