My Symptoms:
- When starting, engine fires right up then stumbles and either stops or I'm able to feather the gas and catch the RPM going from 1000 -> 0 in the middle and get it to run.
- When driving (sometimes) stumbles and hesitates, loss of power then surges back. Evident when driving around at part or even full throttle. Less frequent to start, now more frequent. Seemed like the engine was struggling from lack of fuel.
I went down through the list fixes in the service manual while checking known issues in this forum, I checked all over for vacuum leaks, replaced spark plugs, wires, air filter, adjusted timing (was way off, truck has much more punch now) replaced a number of vacuum hoses while looking for a leak. I replaced the fuel pulsation damper, tested the fuel pressure (47 PSI at the cold start injector) and the pulsation damper definitely made a difference, idle seemed better, but I still felt the hesitation. Replaced (and adjusted) the TPS sensor, and wow! It works. The TPS sensor was the problem.
Still having issues with the fuel charcoal canister and fuel tank not breathing properly, but that is for another day. Trucks running better now. Idle still feels rough so I'm going to adjust valve timing next.
- When starting, engine fires right up then stumbles and either stops or I'm able to feather the gas and catch the RPM going from 1000 -> 0 in the middle and get it to run.
- When driving (sometimes) stumbles and hesitates, loss of power then surges back. Evident when driving around at part or even full throttle. Less frequent to start, now more frequent. Seemed like the engine was struggling from lack of fuel.
I went down through the list fixes in the service manual while checking known issues in this forum, I checked all over for vacuum leaks, replaced spark plugs, wires, air filter, adjusted timing (was way off, truck has much more punch now) replaced a number of vacuum hoses while looking for a leak. I replaced the fuel pulsation damper, tested the fuel pressure (47 PSI at the cold start injector) and the pulsation damper definitely made a difference, idle seemed better, but I still felt the hesitation. Replaced (and adjusted) the TPS sensor, and wow! It works. The TPS sensor was the problem.
Still having issues with the fuel charcoal canister and fuel tank not breathing properly, but that is for another day. Trucks running better now. Idle still feels rough so I'm going to adjust valve timing next.
