1993 ford f250 5.8 won't start it will crank and buck and fire and run for a little bit then shut right back off the plugs and wires are new the fuel filters new the fuel pump is new the ignition control is fine the crash switch is fine its just started doing this last weekend I just put the new fuel pump in still wouldn't start so I put starting fluid down the intake got it to start reved it to 3500 4000 rpm so it would shut back off then I let it come back down to ideal and I switched it to the back tank to see if the was the problem that. That fuel pump was bad then the truck die so I put it back to the front tank with the new pump and it wouldn't start again any ideas on what my problem is would be a big help the only thing I haven't checked is spark but it starts and bucks and fire so you'd think spark is fine right?

 

Put a fuel pressure gauge on it and see what's going on

 

It's getting just under 40 psi

 

Hmm, yes I would assume it's getting spark from how describe what happened, now that you know you have fuel you should still test and make sure it has spark. Does it have any vacuum leaks?

I'm a little confused from how you worded things in your first post, so truck died when you switched to back tank and now won't start at all? Or it starts but is bucking and missing?

 

Some times it does nothing at all or some times its bucks and fires and sometimes it starts will run for a good ten fifteen mins then I'll shut it off and try to start it again then nothing

 

For the fuel pressure...put your gauge on the rail and start the motor, check the pressure. Turn off motor, pull the vacuum line from the fuel pressure regulator and start the motor. Did the pressure go up?

 

I had the same issue with mine by what it sounds like.....Throttle Position Sensor.....I would check the voltage on it.....Or just check for codes...

 

Its not getting spark like it will and then it will drop back out

 

Check the TFI module, they can go bad after getting warm

 

I have two of them I got one from a friend that he said came out of a running truck I put it in and there has been no change the truck still does the same thing so I put the original one back in

 

I re-read the post and based on what you have tried, I would suggest check the timing and/or the idle adjustment screw on the throttle body. Check the screw first...adjust the screw in so it opens the TB more, try cranking. Any difference?

 

His 93 engine won't have a distributor thick film module he should have the fender mounted ignition control module

Also don't mess with the screw on the throttle body, it actually is not an idle adjustment

So what exactly did you get from your friend and install? unless this engine is a earlier model year swap 87-91 it should not have tfi

 

I have the fender well ignition control and that's what my friend gave me to sawp out to see if it was it and nothing changed when I did so I put the original one back in the motor is also the original motor

 

What color was the ICM? Grey or Black? You need the Grey ICM.

Try pulling the SPOUT connector out, and then see what it does. If that fails, then I'm guess that the PIP/Stator is failing in the distributor.

"Eric the car guy", Google that or check YouTube for Scanner Danner. There is a video that shows you exactly how to check for spark on Ford's, with TFI ignition and its a good video.

 

Its the gray one