help with chevy truck

[buzzinhalfdozen]

Sound like Tod Lane hit it, I'd look at The Catalytic convertor. Still sounds as if you have a base timing issue after that is resolved if it still has no power remove the frt, o2 sensor and adapt a pressur gage to the hole start engine should not see more than 1-3 psi at 1500 RPM

[Lew Silverman]

The engine still should run with the brown wire disconnected. The initial timing should be enough to at least let the motor idle. Whatever the label says to set the timing, say 4-degrees before TDC, with the brown wire disconnected, should set the MIL light and a code in the ECM, so you'll have to clear both after you're done with the timing.

Did you have any codes stored in the ECM after the motor started to exhibit the stumble? OBD ll vehicles are usually (but not always) easier to diagnose because of the codes they throw. It might pay to have someone hook a scanner to it, if you haven't done so already. I had a neighbor who's Firebird had a terrible stumble off idle, hooked the scanner up and found the ignition system wasn't advancing the timing at all! No hair pulling necessary!

Just a few ideas...............

Lew

[Ed Wright]

If somebody previously set the timing without unplugging the tan/black wire it will be too retarded when it is unplugged. Most of those should show 12 to 16 deg BTDC with the wire plugged in. Might check it that way. If it's on zero, give the dist a twist so it will stay running when unplugged.

[Jim Woods]

Thank you so much to everyone that responded to help me out. I finally went to the junkyard and bought a distributor out of a running truck, put it in and BINGO the truck fired and runs like new . So now I will fix it properly. Since I changed everything else while chasing the problem it should run well for a long time, Again , thank you very much. It was driving me crazy LOL