I have a 1998 5.7 vortec, came out of a 1998 Tahoe with approx 145,000 miles, it ran good 4 years ago. I pulled it out of the Tahoe and put it in a K2500 Cheyenne automatic. I have replaced the fuel pump (ac delco) it misses. When on the scanning tool (when it's cold) it misses on # 1 - #5 - & #7, then when it's warm it misses on #2 - #3 -& #4. It seems like it just jumps all over the place. The following is what I have already replaced/changed: the ECM - new spark plugs, wires, distributor cap - rotor, coil and ignition driver, fuel injectors, map sensor, the TPS - crankshaft position sensor,
I've done a compression test and every cylender has 190 to 195 psi. If any of you can help me I'll be glad to send you a check for $100.00 asap as I need to get this truck up and going for work!