I've got a friends 90 chev, 4x4, 3/4 T, 5.7 std shift trk. The problem is when you hit the throttle it boggs. Setting still you can roll into it easy and the rpm will go up, on the road you have to barely give it gas and get into high gear as quick as possible and try not to put into any extra load to get any speed up. It has a new tank, lines, FP, and rebuilt throttle body from a problem 2 mths ago. I've cked map, FP press, ECM, Dist, grds, and you name it. It had a O2 circ code and wouldn't go into closed loop, fixed that and installed new plugs, they were fouled, and put a new gm cap and rotor. Tried a good coil I had here also. No codes now and everything on data list looks good. Starts and idles great, hit the throttle, setting still, and it starts to rpm and then just boggs or flattens out. Adding or taking away fuel doesn't help. Has anyone got any ideas because I'm out.
04-08-2013 06:05 PM
Drop the exhaust system right from the manifolds. The cats may be plugged. If Dropping the pipes clears it up, then the exhaust is plugged.
04-08-2013 07:02 PM
No cats and the exh was just put on. Went over it with a temp gun. But that is the way it acts.