I am coming to you all for expertise on this. The good news is the weather in Missouri has allowed me to enjoy driving the beast all winter (most of the winter) instead of leaving it parked in the garage covered.

The bad news is yesterday I took it out to enjoy. Started fine, backed it out of the garage and as I let the clutch out it stumbled, wanted to die, but I kept the RPM's up so it would not (did not know if it would not start back, leaving me looking for a way to get it back in the garage with an uphill driveway). Bascially everytime I gave it trottle and let the clutch out to move the vehicle is would stumble and fall on it's face. I managed to get it back in the garage under its own power, let it idle to normal opearting temps. Then I tried to move it out again as it seemed fine letting the clutch out slowly again. The check engine light was on I should mention during this phase (upon the cold start).

Drove it the rest of the day w/o issue and no check engine light, however it never sat long enough at the couple of stops I made to get real cold.

Again, this happened with a cold start, in open loop. It was fine when warmed up in closed loop operation. Now, I am not running an EGR valve (miniram equipped), and I have no airpump and the attachments to it. Could this be an o2 sensor?, MAF sensor?, I don't know as I have a mechanic (GM technician and GM performance guy) that I trust who has performed all of my modifcations, repairs, maintenance, etc. but have not contacted him yet (maybe I don't need to yet). The car since I have owned it (since April, 2001) has been professionally wrenched, well maintained, etc. so there are no defferred maintenace issues on this car as most things have been replaced with improvements, updated, etc. This is by no means a low budget C4.

See my signature below for the details of the car, 1985 6speed ZF equipped.

Thanks for your all's help! and let me know what details I left out

 

You need more cold enrichment in your tune. And probably more specifically, more cold acceleration enrichment.

 

Another possibility is the temp sensor. If the ECM thinks it's warmer than it really it, you won't get the necessary open-loop enrichment.

BTW...if 85 is the same as 89, the ECM's sensor isn't the same as your display. Two different sensors, two different readings. You need a scan to see what the other sensor is doing.

 

Brought it back from the shop today after they called to let me know they found the problem. Turns out it was giving a code for the MAF. This would make sense since it is one of the few items I have not replaced on this car and I believe it to be the original. The shop installed a new MAF sensor and they reported no problems. I picked it up, no check engine light anymore and seemed fine. Although, I did notice is it searching for a good idle speed and is idling a little lower than before (like around 600RPM and then levels up to around 800RPM). It actually died once right after I left the shop. I went back to let them know. They thought it would be a good idea to drive it around a little first. I am hoping the idle eventually levels out if the ECM can make changes. The PROM is custom from TPIS with the mods the car has, so.......

 

If they put in a rebuilt MAF sensor you may want to do a datalog and see if your Air/Fuel is where it belongs.. I tried 3 rebuilt MAF sensors and still didn't find one that was calibrated correctly. If Mick Stevens hadn't noticed the car running extremely lean when he was doing my tune it could have caused engine damage.. On one of the rebuilt MAF sensors the specs were so far off my Vette wouldn't even start. If its not a new maf sensor this could be the problem...WW

 

Thanks for thie info!

I will keep that info close incase I continue to have driveability issues......overall however on the drive home which was roughly 15 miles, it ran very, very, well when driving down the road, shifting gear to gear, and under acceleration.......it just seems to be at idle.....

 

Mine drove very well also, the problem was the BLMs were at 150 which would have damaged my motor in a short while..I always check my motor with a scanner anytime I add a part that can change my Air/Fuel mixture....Always...The point I am trying to make is, if they used a rebuilt MAF sensor ,alot of these are known to be way off spec and you should check to make sure your tune has not changed because of it..Even if it appears to be running fine, because not checking can be disastrous.....WW