Alright so ran through the checks again and it holds steady at 40psi when just in the on position when i turned it off the pressure started to drop but was not rapid at all very gradual. Plugged the vaccum and it held about 43.3 ish psi. Drove the car around when cold and then heated up and never fell past 41 psi. I was was told to unplug the maf and check the fuel pressure and that was the same which idk why that would make a difference in pressure if that is plugged in or not. But what leaning more too is shouldnt the car run worse when the maf is unplugged? Because the car still runs the same if i hook the scanner up what should the reading of the maf be at?

Thanks for all the help

 

So I took my car to the dealer and told me its not missing and there are no dtcs. The said that there was a recall on the air pump. So they changed it and this is the read out at idle after I got it back
Its still running ruff but not as bad is there anything I can check here is the read out of the o2s at idle

 

What does "hot" mean? is it when it goes into closed loop?

Based on your pics it is not running lean.

the spark changing by that much at idle is completely normal.

do you have a real datalogger that shows graphs and ALL data from the PCM?

go into very detailed explanation of what happens and when it does. "it missfires every 3 seconds after the coolant reaches XXX"

 

They fixed the lean condition which was they air pump. The fuel is not pouring into the motor anymore. And hot meaning operating temp. When i start it when its cold it runs fine but as soon as it gets up to operating temp it starts to run rough. Gm said that when they hooked it up to the computer they found nothing wrong with it and said that the car had been tuned which i did not know. They said that the tune is with in specs and could not find out anything wrong with it.

I do not have a data logger only thing i have is that scanner. Gm said that all of the cylinders are firing properly. But im thinking it could be the icm getting heat soak. The car will miss every couple of seconds. Im thinking about doing a fuel treatment and seafoam it would that be a wise choice? Im also going to clean the maf again.

 

It is not your MAF. Don't clean again.

Nothing wrong with cleaning injectors but if it was injectors, your fueling would be off constantly. Your fueling is not off.

It is probably not your ICM.

I would check your plug wires for burnt areas. This could cause intermittent misses that the PCM will not compensate for if long enough between misfires. Plug wires must be good to go and not burnt, stiff, cracked, brittle anywhere or it could cause this. You must not only look but "feel" for plug wire issues.

After that, I would go opti.

Also, what is the car doing at cruise and WOT? stressing a ignition system will generally show other symptoms and help diagnose. Can't just look at idle hence why I spoke on datalogging.

 

Ok thanks guys i think i figured it out. What im guessing is a clogged injector because i seafoamed the car and put an octane boost in it and now it runs smooth. I just dont see how the dealership couldn't spot it when it was hooked up to the computer. Thanks guys for all of the help.

 

If it's not giving a miss-fire code, the only way to find it, assuming it idles rough enough, would be to deactivate each cylinder. But then pulling the fuel rail up only involved a couple of screws and 10 minutes time.