89 Silverado Dually, 454 TBI - New to me truck. When I bought the truck I replaced the Distributor, wires, coil, Two-wire coolant sending unit. I rebuilt the TBI and replaced all associated gaskets. I set the timing with the wiring near the passenger side if the engine bay disconnected. I set it at 4* BTDC (ended up being 5* after distributor tightening). It ran, idled, and drove great for about 100 miles. Today I started it up, it is cold outside, it started fine. I put the chains on while it was warming up. I noticed the exhaust was rich smelling. Very rich. A few minutes later the truck died when trying to back up. Now it will start if I give it throttle but dies when I let it idle. Smells rich. I checked all wires, vacuum hoses, etc and did not see anything broken, cracked or disconnected. I can't move the truck or it dies even when feathering the throttle. IDEAS?
Update: I replaced the MAP sensor - someone suggested it. It did not help.
Final update: In the end, it was the fuel pump. The original pump worked for a while, then didn't, then kind of worked, then it only worked when I would feather the throttle. I initially used a friends fuel pressure gauge that he had made. I later found it was not working correctly. I bought an inexpensive pressure gauge and it showed my fuel pressure was only at 3 psi. I installed a new fuel pump assembly and got 15 psi. I have also installed an adjustable aftermarket fuel pressure regulator. Read through this to find a lot of useful diagnostic information.
Update: I replaced the MAP sensor - someone suggested it. It did not help.
Final update: In the end, it was the fuel pump. The original pump worked for a while, then didn't, then kind of worked, then it only worked when I would feather the throttle. I initially used a friends fuel pressure gauge that he had made. I later found it was not working correctly. I bought an inexpensive pressure gauge and it showed my fuel pressure was only at 3 psi. I installed a new fuel pump assembly and got 15 psi. I have also installed an adjustable aftermarket fuel pressure regulator. Read through this to find a lot of useful diagnostic information.
