1994 Chevrolet 3/4 Ton Truck – Throttle Body Dumping Fuel

Reader Question: My fiancé’ bought a 1994 Chevrolet 3/4 ton truck (4×4, 5.7L, V8). The throttle body is dumping fuel into the motor. He changed the plugs, wires, distributor, cap, rotor, fuel1 filter, and computer. He checked the timing and it is good.

However, all this was done with no result. He also bought a book on this truck and had a mechanic look at it.

He only bought the truck 3 days before this happened. He was driving home from work and it just stopped.

Do you have any ideas? He is spending all my money and his time trying to fix this and it is not working.

I would greatly appreciate any help you could offer!

Thank you,

Holly

Hello Holly,

The best thing to do is start from scratch here. He has to be missing one of the main ingredients to start the engine, spark to the spark plugs, proper fuel pressure and ignition timing and compression.

If he can see visible fuel coming down the throttle body, my only concern would be is it at the proper pressure. He can rent a fuel pressure gauge from the auto parts store, screw it on to the engine, and crank the engine over to test fuel pressure. You can also bang on the bottom of the fuel tank AS someone cranks the engine over, this can jump-start a weak fuel pump.

If he is sure he has proper fuel pressure, the next thing to do is check for spark at each spark plug. If there is no spark, check the ignition coil and the ignition module and distributor for spark.

If he has spark and fuel, then this might be a compression or timing chain issue. Sometimes the engine will spin over faster and sound funny when the timing chain breaks or there is internal engine damage.

Before he spends any more money on this I would highly recommend he tow it to a qualified mechanic and have them diagnose the problem. He can do the work himself once he knows what the problem is.

Blessings,
Austin Davis