1987 Chevy with 350 TBI. NO A/C . posted an 87 here because ya'll are more familiar with TBI engines. Just did a head gasket job on this. truck ran fine before doing gasket job other than the sweet smell in exhuast. Everything is hooked up as it should be and the timing is set about 4* advanced from where it should be at 0*. moved it both ways with brown/black wire disconnected and connected and it made no difference in running. the truck starts now, but runs like crap. It lopes and has HEAVY fuel smell from the exhaust like it is running 'full rich'. The injectors even look like they are putting too much fuel in. I remember what it looked like when it was running good and it appears to be dumping in lots more fuel now. The 'CHECK ENGINE' light is working, but I am not getting any codes. I disconnected the battery for a long period several times to let it reset but it did not change anything. should I do the jumper between A &B to see if i am getting any coeds anyway? thanx for any help, DAVE

go ahead and and check codes you should atleast get a 12 out of it.
is there good vacum going to the map sensor?

Crossy, assuming your 87 is same as later tbi trucks and if you haven't already replaced this, I'd say maybe your coolant temp sensor is bad or has a bad connection. Sometimes when they go bad it will cause it to dump large amounts of fuel in the engine. Some will run bad until fully warmed up and be fine also. They don't cost much. This CTS is mounted beside the thermo housing. Maybe that will get it back going for ya.

Crossy, assuming your 87 is same as later tbi trucks and if you haven't already replaced this, I'd say maybe your coolant temp sensor is bad or has a bad connection. Sometimes when they go bad it will cause it to dump large amounts of fuel in the engine. Some will run bad until fully warmed up and be fine also. They don't cost much. This CTS is mounted beside the thermo housing. Maybe that will get it back going for ya.

:agree: For a quick test, just unplug the sensor and see how it runs. If it runs better you have to replace a $6 sensor ;)

Mike

I found my problem this morning. the line coming off the back of the TBI unit that runs directly to the MAP sensor was cracked bad enough that the MAP was not receiving the proper vacuum. I was tipped off by a Chevy tech that i needed to check the MAP sensor and i did so ASAP starting with that vacuum line. I looked at all my lines good(I thought) before re-installation, but it must have split while i was putting it back on.
hope that helps you too. DAVE

vaccum to map sensor maybe, my prob was similar and the ignition coil was on its way out, changed that and it ran fine

Ign colis and the pickup in the dist. are commor to go out,The dist pickup coil fires the speed of injectors...Common problem..on TBI motors