I have a 2000 Jimmy 2wd automatic with a 4.3 vortec.
I got the car about a month ago and ever since I got it it's had an odd problem. It runs like a champ at 1/2 throttle or less, but if you give it much more than that it starts sputtering and loses all power. It didn't turn on the check engine light at first, so I cleaned the airflow sensor, replaced the spark plugs & wires, checked the air filter (looked new) and replaced the fuel filter. I put some heet in the tank because I thought there may be water in the fuel (several tanks ago) all with no results. Finally I was driving it one day and the check engine light came on. I took it to auto zone, they plugged it in and it wouldn't power up the scanner. Took it to my dad's house to try his scanner and the same thing happened. All of the wiring to the obdII port that was visible looked fine, I was going to try to ring out the port wiring, but the stupid haynes book doesn't have that wiring diagram. Also, no fuses are blown.

Any ideas are appreciated

Also, I don't imagine that it's related, but just in case, the air conditioning isn't working.

 

On the OBD2 port, check the CIG fuse in the instrument panel fuse box located on the driver side of the dash accessible with the driver door open and the cover removed.

Let us know what the code is and we'll try to help from there.

 

Checked all of the fuses, they're all fine and dandy.

 

Have you checked for constant power at pin 16 and switched power on pin 2 on the DLC? How about good ground to pins 4 & 5?

 

ok, so apparently I lied and you were totally right, that fuse was blown. I replaced it and the spare fuse also blew, so I've got something funky going on somewhere. Is this a common problem (hopefully with a common solution)?
Thanks for your help, you've already saved me headaches.

 

Is there something down in the cigarette lighter socket?