TBI fun

[78SWB]

My ‘88 K5 will sometimes fall on its face when the engine is cold, starting from a stop. It also feels under powered. It will sometimes miss fire then randomly come out of it and run great for a few seconds then goes back to running okay. Once it’s warm it usually runs okay but seems like it’s under powered compared to my ‘87 V20. I’ve replaced the fuel filter, plugs, wires, and egr valve. Anyone have any ideas?

 

[jekquistk5]

My ‘88 K5 will sometimes fall on its face when the engine is cold, starting from a stop. It also feels under powered. It will sometimes miss fire then randomly come out of it and run great for a few seconds then goes back to running okay. Once it’s warm it usually runs okay but seems like it’s under powered compared to my ‘87 V20. I’ve replaced the fuel filter, plugs, wires, and egr valve. Anyone have any ideas?

tunerprort and odb cable. Log and you will find what the issue is. Unless you have lost some compression.

 

[GWeakland620]

Yeah logging will tell you if you are having a map sensor issue or whatever.

 

[86454K30]

I'd bet it has a bad distributor.

 

[78SWB]

Seems to be running noticeably better now after replacing the cap and rotor. Not 100% though. Rotor was stuck on so bad it broke coming off.

 

[skunked]

the cap has some funny wear marks on it too.

 

[78SWB]

the cap has some funny wear marks on it too.

Yeah definitely. I believe they were original. They both said delco-remy on them.

 

[78SWB]

Changed the coolant temp sensor. Fixed the issue of cold engine falling on its face and is running pretty good in open loop now. Runs great in closed loop.

 

[78SWB]

Also there were no trouble codes stored on this truck.