Hi guys,

I've looked at those who've had the same problem as myself, but it seems that they all have the newer CPI injection... so hopefully I'm not kicking a dead horse. 91 4.3 TBI Tahoe edition here with 200k miles here.

Basically, my car runs very well except once I get to a red light at an intersection. The car starts idling very rough, the entire car shakes, the dummy light comes on, and I've experienced it die. Anyway, I don't know what dummy light comes on... and I'm not exactly sure how to check for fuel pressure/vacuum leaks, but I am more than willing to learn as this is my daily driver.

I've read elsewhere that it could be a weak fuel pump, build up in the cat, bad egr, vacuum leak, or bad plugs. Unfortunately for the troubleshooting... I believe I've had my fuel pump replaced in the last 5 years (done to fix this same problem), my car was replaced when I got a new exhaust (mine was rusted out), my egr has been replaced twice, my plugs have been changed out twice after two tune ups in the last 5 years of ownership, but vacuum leaks.... not sure.

In order for the car not to die, I've had to shift it into neutral and kill the ac (my temporary fix at a long light); however, reengaging the transmission into OD makes the car buck harder than when I was just sitting at the light (but goes away once I've hit the accelerator). I've noticed 9 out of 10 times this happens, my oil pressure gauge plummits, but I've been told this has nothing to do with my issue. So 2 problems, I suppose.

Any insight would be a massive help. Thanks fellas!

 

I've noticed 9 out of 10 times this happens, my oil pressure gauge plummits, but I've been told this has nothing to do with my issue.

Have you tried replaceing the oil pump? Also the MAF could have something to do with your rough idle also maybe distributor and rotor. My car would barly move out of its own way and it turned out to be the distributors.