Problems on start Built Engine
 

been having issues recently after getting my car back after building the engine.

IAG stage 2 short block 10:1 Comp SBD 500x Turbo

The engine is fully broken in and runs perfectly fine besides when i start it.
Occasionally has misfires but hasent had that problem in a couple weeks or so.
is really choppy and wants to stumble or stalls the first minute or so when i start after that it clears out and is fine.

ive checked for vacuum leaks and have found none, spark plugs are brand new, i have new injectors.

recently cleaned the throttle body but with no luck. car is tuned by bill @Delicoustunning and hes just as confused as me. ive sent him over 10 start up logs and nothing can fix this. as i said ive checked everything i know of that would be causeing this issue and browsed multiple forums trying to fix it. also my pi and di scaling is all correct so thats not causing the issue and as i stated it only happens on cold starts and start ups other then that it runs perfect.

if anyone else was having this problem and knows how to fix it please let me know.

I have the same issue. I still have yet to figure it out after 2 seasons of driving it and pulling the motor apart multiple times. I've swapped numerous sensors and parts from my original engine and never was able to figure it out.

Try putting the stock MAP sensor back in and see what happens. Maybe Bill forgot the MAP scaling somehow?

I had similar issues. i replaced my MAF sensor ($270) which helped a little, then I switched tuners to Zach at counterspace... no issues since.

While Zach is great(I am tuned with him) bill is just as good. Bill will get him sorted.

Sent from my GM1915 using Tapatalk

Tried using IAG? I'm always happy with the work they do for me.