Engine Mechanical problem
1996 GMC C3500 V8 Four Wheel Drive Automatic 117000 miles
Still love my old dog dually GMC. I'm not a diesel man, so I'm keeping my 96 7.4L vortec. I pull a 13k trailer with it, and lately when I'm going up hills the service engine soon light comes on. It also smells like it's running very rich. (you can smell the raw gas).
I took it to a shop and they said the code was the timing was off. They re-timed it. The very next time I towed with it going up hill again the service engine soon light came on. The light went off before I could take it to a shop and have it tested. (about the 3rd time I drove it with out the trailer). It still smells like it's running rich, and gas mileage is about 8 mpg.
Truck is total stock, and all original (but I have replaced spark plug wires, cap, rotor and so on). I have two questions 1. What will cause the rich smell, and the service engine soon light to come on while towing up hill, and then go off once I'm not towing..
And 2.. What kind of no B.S performance upgrades can I do. Exhaust, TBI spacer, computer chip?? (I do NOT WANT to put headers on this truck). I just want this truck to run another awesome 117k miles for me.
have the same problem?
Saturday, January 30th, 2010 AT 8:17 AM