I have a 93 d150 with a remaned 318. First start of the day, it will fire right up and idle fine but will smoke alot. I'm able to drive it for not even a mile and it dies on me. Then it won't fire back up unless I hold my foot to the floor. Even then it doesn't stay running. The truck has a new fuel pump and i did a fuel pressure test. When turning over it has about 39 lbs then it slowly looses pressure. It also has a new distributor. I pulled the plugs to see if i am getting spark and i am. I noticed that the plugs are jet black. The throttle body was also just cleaned. Does anyone have any idea what this could be? Also my temperature gauge no longer works. Can anyone tell me what sensor controls That?

 

Hello

I'd say it's definitely getting too much fuel. I've no experience with fuel injection set ups but, I have some ideas.

Check for vacuum leaks. Leaks will through off the computer making it richen the fuel mixture.

You said the fuel pressure bleeds down? Try this. Disable the ignition system, take off the air cleaner and check for a leaking or stuck open injectors.
I could be wrong but, your shouldn't have to crank the engine to pressurize the fuel system, the pump should prime every time the key is turned to the ON position.

You could also check injector spray pattern with a timing light while the engine is running.

As for the gauge not working. I believe these have two temperature sending units. One for the temp gauge and one for the engine computer.
The one for the gauge should be a one terminal sender. If you take the wire off it and ground it out the temp gauge should peg out on HOT. This will at least tell you the gauge itself is working.
Don't do this to the ECU sender wires.

If the ECU sender is bad and reporting cold readings to the ECU. The engine will run fine at startup and get worse as it warms up because the fuel mixture will stay rich.

You said it has a reman 318? Is this the size same engine the truck originally had? If not was the ECU swapped or reprogrammed for the current engine?


Thats all I can think of at the moment.

 

Yes truck did come with a 318 from factory. When I bought the truck it had a blown motor. I then bought a motor from my local auto parts store that is considered restored I guess. But to me it also seems more like a fuel problem. I'll look for vacuum lines that aren't connected. If I can find any I'll have look further into the fuel rail and injectors.