Code 42. Engine stalling.

Ruddell

Member
Hey guys. I need help please. I took my Ty out for the first time this year and came into a stalling issue. I put 10k miles on this thing in two years and its never skipped a beat.

It's all stock other then new fuel pump/sending unit, fuel filter, cap/rotor, plugs all done last year prior to putting on 5k Miles.

I was given code 42. I replaced the ICM with a AcDelco, wire brushed the already clean mounting bolts.

This did not help. When i start it, it runs for three seconds and then stalls. Code 42.

If I held the throttle it would stay running. I went ahead and cleaned the IAC, and this did keep it idling after. But it would stall after giving it some throttle. Code 42.

I replaced the IAC with a AcDelco and started it up and it ran and idled great. It appeared fixed. So put the IC back on, about to go for a drive, and we are back where I started.

Runs for 3-5 seconds max and then stalls. With code 42.

I feel pretty lost at this point. I'm not sure where to start.

Thank you for reading.
 

Ruddell

Member
No I didn't. I have since been told that it's the knock sensor causing this. I am not sure how the heck I'm going to access it.
 

Poconojoe

Donating Member
All the knock sensor can do is retard the timing, so take a timing light and watch the timing, but I doubt, its a knock sensor issue, you could just unplug it also, since the motor will run without it
 

Sy2622

Member
Do you have the ability to see what your IAC counts, open / closed loop. These will help with troubleshooting.
 

Ruddell

Member
I checked the timing with the tan wire disconnected when it was still running it was off...
I don't have data master and it dosnt run for more then 3 seconds. I can try unplugging the knock sensor and see if it runs without it...
 
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Ruddell

Member
Update. I replaced the knock sensor and the code 42 went away. Great. But my non idle or starting issue remained. I ended up buying another new IAC and put it in and it's been fixed ever since. The first new Gm Genuine # 17112193 i got did absolutely nothing. It was faulty!!! Ugh.
 
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