As a test, you can try 2 things. One is unplug the MAF sensor. There is a default table that the car will be drivable, but rich if you are not at sea level. That will test for a bad MAF.

When the car is running, put your hand over the exhaust and then smell it. Does it smell rich like unburned fuel, or acrid like it's lean? If rich, try unplugging the coolant sensor and bridge the terminals on the wiring harness connector with an unbent paperclip. That will tell the ECU that the engine is fully hot and see if the drivability is better. If you leave the connector unplugged the ECU thinks it is -40C and will go to full enrichment.

Other thought, since you were pulling coils, did you mix up the #5 and #6 wires/connectors to the coils? That's easy to do.

For plugs, these cars are very fussy about what sparkplugs they use, they like Champions the best. Don't use platinum plugs, just regular copper ones.

 

Just watched your video. I noticed as the engine was rocking on it's mounts as you revved it, the rubber bellows on the air intake didn't seem to move. It's right under your thumb in the video. I would check that the bellows is firmly attached to the throttle body, and the hose clamp that holds it on is in the right place.

I'm suspecting your bellows is not seated all the way around on the throttle body and you have an air leak. It's air the MAF can't read, and it's leaning out. The bellows can be difficult to get on the aluminium throttle body, especially on the bottom.

 

Unplugging maf stall the car instantly. And I measured it's output voltage and seemed fine.

Also my coolant sensor show good data on my scanner. And I don't think the exhaust smell anything

I'll check the intake rubber attentively

 

You did flush out the fuel with some known fresh fuel? You would be surprised what even a little water in the tank can do, leaving aside the effects of ethanol based fuel breaking down. Colour isn't always a tell tale.

 

Yes I did. And Friday I decided to try the crank sensor since so many people recommended it. And that was my issue. The engine go much better now!! Thanks everyone

 

Excellent !

 

CHRIST..............at last....Was it the Crank Position Sensor!!!!!!!!

 

Just been speaking with my mechanic about this, we have both never seen a crank position sensor fail like this, and we have a fair few years between us...they either work or they don't.

These X300 CPS also exhibit the opposite of a typical normal failure in that they fail cold (OK after a run then will not start when left) where most will start and fail when hot, but I have seen GM ones fail like this on the odd occasion.

I'm wondering if I should change my CPS due to my cold start problems, even thought it goes against normal logic

 

Stupid question. Do you have oil in the coil wells?