Get this. I started blowing the fuse for the ECM. It would go mayby .5 mile at the best. I thought it was going to be a short some wheres or the ecm. I looked at the schmatic and it fed the ecm, oil pressure switch, and lift pump, among other things. This pickup had symptoms of a bad lift pump, but it was 6 months old and AC Delco. Well I decided to unhook the lift pump to start out. I replaced the fuse and it has not burnt out yet. I put in the new pump, but I still have the same problems with drivability. IT jerks in light throttle and will smooth with more pedal. Filters at less than 2500 miles on them. Go figure.

If you get a bad batch of fuel your filter will plug up quick, you might try changing it just to make sure. How many miles on your truck? Where in Montana?

Sidney area. I will change the filter if I get a chance. It has about 106,000 miles. The pump is suppose to be the original pump. The prev. owner had it from 45,000 till I bought it last year. He didn't touch anything on it. It ran soo sweet when I bought it I couldn't pass it up, 6.5 and 1/2 ton is such a nice combination. I would love to see that come back, a turned down duramax and 1/2 ton.

there are rumors of a v-6 duramax in half-tons and suburbans

smart move by the General

Glad to hear you solved it, that was a real strange one.


BTW...there is a duramax 7.8L 6cyl inline...but not for ½tons, medium duty trucks. Edited by: Texas Diesel Guy

yeah i have read a little about these motors


i think i would have to lean towards the cat though if i was gonna get a 6500 or 7500.