I've got a 88 with a 7.3l idi, this truck cranked and ran a year ago when we parked it decided to get it back on the road. The manual fuel pump went out so we changed it with a electrical pump and worked great. Now after sitting it will not crank on its own. I've replaced glow plugs, alternator, voltage regulator, battery's and cables, and starter. I'm able to pull start the truck I let it run for a couple hours thinking it had air in the fuel lines went back outside turned it off and tried cranking it on its own and it wouldn't. I'm completely stumped on this . Any and all help will be greatly appreciated .

 

Have you tried jumping the starter relay? Jump from the large terminal that's connected to the +battery to the small terminal (make sure it's in neutral). If it cranks, then check that the wire to the small terminal gets power when the key is turned to start. Possibly the clutch interlock... If it doesn't crank, jump across the 2 large terminals with something substantial. If it cranks now, the relay is bad...

 

It turns over fine just won't start

 

Have you tried giving the batteries a good charge since you put them in? You would think they'd be fine being new but I've heard before that if there's not enough juice to the starter these engines especially will crank and crank but just not turn over fast enough to start even though it appears to be cranking fine... That's all I can think of and its pretty easy to try, good luck.

 

Yes I have but thanks for asking

 

i just want to clarify as your posts are confusing as one post states it is not cranking and the next states it is?

 

so the engine turns over, but will not start?
when you bump started it, how did it run?
any smoke from the exhaust? if so, what color?
does the wait to start light come on? how long does it stay on for?
is the electric fuel pump working? if it is,m what is the fuel pressure at the filter head?

 

White smoke comes out the exhaust , haven't checked actually fuel pressure but the electric pump is pumping slot of fuel to the filter, the wait to start light doesn't come due to the timer bring out and we hooked it up to a push button ... Engine just turns over but will not crank and runs good when we bump start it

 

Cranking means the engine is being turned by the starter, that's what is causing some confusion. So your truck cranks but won't start, right? It sounds like you are getting white smoke out of the exhaust while cranking, correct? If so that means you are getting fuel through the injectors but it is not igniting. Most likely causes would be glow plugs not working or engine isn't cranking fast enough.

 

white smoke out of the exhaust and no wait to start light tells me the glow plugs are not working. what type glow plugs did you put in it? anything other than motorcraft ZD-9's, i bet they are burned out already.