Help truck won't start!

[James670X]

Help truck won't start!(updated)

It's a 1988 V30 (SFA, old body style) with the 454EFI and it's not starting (doesn't even crank over), however the headlights still work and when the key is turned voltage drops a little. This is frustrating the hell out of me because it will do this periodically (most of the time it will start when I want to try and diagnose the problem). I've tried hammering the starter, boosting it and these do nothing.
Any ideas/suggestions???????
Edit: So far I've replaced the spark plugs, plug wires, pcv, air cleaner, crankcase filter, 02 sensor, fuel filter, distributor, rotor, timing has been adjusted (tune-up items), the relay switch for the two tanks has been replaced, fuel pressure regulator has been replaced, fuel switching mechanism has been replaced, the ignition switch on the column has been replaced, the fuses (inside the cab) have been checked.
Your response will be appreciated
Thanks
James

 

[big83chevy4x4]

Re: Help truck won\'t start!

if its not cranking, then id look at the starter, wireing for the starter, and solenoid.

what i would do is pull the starter off and get some pumper cables and a good battery and test the starter. just hook the ground to the nose cone or the stud on the back, and the positive on the big terminal on the starter and jump it to the inside little one. if that doesn't work, try hooking the positive it on the terminal that goes from the solenoid to the main body of the starter. the starter should spin here no matter what. if not, the brushes inside are shot.

if the first test doesn't work but the second test does, the solenoid needs replacing. if they both work then the starter is most likely not the problem.

 

[bigblock44k5]

Re: Help truck won\'t start!

Check your battery cables first of all. when you turn the key to crank, are you here the solonoid clicking? hook your booster pack to the starter directly and see if it turns over.

 

[James670X]

Turns out that it is a fuel delivery issue not a spark issue. Does anyone have any ideas as to what could be causing this problem?
Edit: All fuses have been checked, the fuel pressure regulator is new, the fuel pump makes noise (pumping), the fuel filter has been replaced, and the throttle body has been taken apart and cleaned.

 

[rooferbret]

Could be a clogged fuel pump sock in the tank.

 

[dyeager535]

Are the injectors firing when the engine is cranking?

I don't understand how no cranking turns into a fuel delivery or spark problem though?

 

[James670X]

Oh sorry about that the first post was another problem that I had with the truck, I've fixed this problem since then (replaced the fuel pressure regulator), this is a completely new problem whereby the motor cranks over fine, but won't start due to fuel delivery issues (it sputters to life on ether).
Dyeager535 the injectors are not firing.

 

[dyeager535]

Is the distributor new or known good? If the ECM doesn't see that the engine is cranking, then that could be an issue.

However, it is probably more likely that the coolant temp sensor for the ECM is screwed up.

This is all speculation though, I guarantee there are more things that can cause a no-injector pulse condition. Beg borrow or steal a scanner, it will at least save you from replacing the coolant temp sensor. If it doesn't read within about 10* of ambient air temp, it's bad. I hate replacing things that might be working fine, there is no guarantee the new piece is any better in this day and age.