Bad Day in the GN...What gives?

[Mountain GN]

Took it out today, drove the **** out of it and nothing. No codes, no stumbles, no problems. Even ran it up to 18 PSI and it pulled smooth and clean. Of course, it was only mid-90's toady and not 110, so that may have made a difference.

 

[motorhead]

It's your fuel pump overheating/wearing out.

Put the car on the same death march as you did when it failed and your situation will return.

 

[boots g]

These last few weeks my car has done similar things. It would ride fine for a little while and then all of a sudden the stuttering, missing, check engine light flashing simultaneously(No codes)would occur. Let it cool, then take a few 22lbs hits without problems then the symptoms would gradually show up again. Saturday morning I found that one of the pins on the ignition module was bent and didn't appear to be lined up with its slot. I straightened this out then the problem went away. So I'd vote to take a look at the ignition module as well. I also tried changing the ecm with a known good one before finding the pin bent, but this didn't help so I dug a lil deeper.

 

[Drewster]

low O2s and a 5 yr old fuel filter?..... i would change the fuel filter just because its a spring cleaning thing.
I had a TPS that would cause sputtering when hot. couldnt figure it out till I caught it reading 0.2mv on the scanmaster.
Good possibility something electronic under the hood overheating since it went away on a cooler day. The coil pack is the most obvious and subject to engine heat. If its still stumbling after swapping the module and coils, see if you can get the motor hot and stumbly again and check out the scanmaster readings. Maybe you can see the tps,iac,maf going crazy. if the stumble is gone then move onto the cooling system to prevent future overheatings. reving the motor a little in park is a good way to get the motor hot again.