I purchased a truck that I had in the past and sold to a friend. He blew the motor up in it so we built a new engine for it and it never got installed. Sat on the engine stand in my shop for almost two years. I bought the truck back from him and got it back together. I have it running but it runs like crap and skips and pops when you try and rev it up. I have drained out as much of the old gas as I can and replaced it with new 93 octane fuel (6 gallons) I replaced the fuel filter, which has clear gas comeout of the old one. How can I tell if the Air Idle Circuit or the Throttle Position Sensor is bad. Timing is very close. I need to get this thing up and usable, I have already spent to much on it as is. Any help would be appreciated.

 

Sounds like you have spark plug wires mixed up. Check your firing order.

 

X2 on spark plug wires. Could you elaborate on "Rebuilt"..
Flat tappet cam, roller cam, heads...
That will help us.

 

Thanks guys for the responces. I didnt even think to check the wires. I will do that. As far as rebuilt, everything new inside engine. Stock rebuild. All machine work done, Heads, crank, block. Distributor is a stock electronic ignition. Cam is hydraulic non-roller style.

 

Be sure the firing order matches the cam.

 

+1 on the firing order. Make sure you have the right firing order, then check the wires. The spec sheet from the cam will tell you the firing order.

 

Cam should be a stock cam with standard firing order for the 5.8. Everything was bought for the 89 5.8, the engine we built came out of an 89 Ford Bronco 5.8 4x4. I dont have the stuff that came with the cam. It was bought with the kit and everything came from the local machine shop that did all the machine work.

 

OK, ran the wires and they are wired correct for a stock 5.8. I did notice however that the battery light is on. I dont think the altenator is charging. Will a weak or non-charging altenator cause problems like I described?