Starting Issue

Hi all, I am new to this site but I heard good things. I am having an issue with my '96 F250 7.3L. If I leave it for more than 5 hours or so and the temp drops to normal I have a hell of a time getting it started (it's spring here and is not dropping below 40 degrees even at night) . Lately I have been unable to start it at all (even if it's 80 degrees out) and yet if I plug in the block heater for a bit, it starts right up right away like it was brand new. Any ideas?

I have read the forums a bit and have an idea of a few likely solutions but unfortunately I'm a poor college student and I would like to try my best to fix the problem on the first try. Any input would be great, thanks.

-Snake

Hey Snake!

If it starts right up when you've used the block heater, that's indicative of the glow plug system not working. I am a little surprised it won't start in 80 degree weather though, I'd think a disel would lite off in the 80's w/o any assist???

The most likely culprit is the glowplug relay. The easiest way to diagnose that is on a cold start, take single clamp from a set of jumper cables and bridge the two large posts on the glowplug relay (this replicates what a good relay would do when activated). Make sure none of the other ends of the jumper cables are touching the truck or each other.
Do this and wait about 30 seconds (key on or off, doesn't matter) then turn the ignition on and try to start the motor. If it fires up, replace the relay and you are golden.

Try that first, its the more likely issue. If that doesn't work you'll want to start checking individual glow plugs and under valvecover harnesses.

We can explain the g/p testing process if jumping the relay does cure your problem.

God bless,

TC

Oh, the glowplug relay is located on top of the motor just inboard of the passenger side valve cover between the alternator and fuel filter housing. It looks like a starter relay that Ford normally mounts on the inner fender. It has two lager terminal posts on it and two smaller terminals. The small ones are low current wires used to activate the solenoid and the large ones carry the high current to the g/plugs. If one of the large posts still has a rubber boot over you'll need to peel it back. That one is the hot from the battery and the other large post is where the "Hot" is connected to when a working solenoid is activated.

TC

Hi all, I am new to this site but I heard good things. I am having an issue with my '96 F250 7.3L. If I leave it for more than 5 hours or so and the temp drops to normal I have a hell of a time getting it started (it's spring here and is not dropping below 40 degrees even at night) . Lately I have been unable to start it at all (even if it's 80 degrees out) and yet if I plug in the block heater for a bit, it starts right up right away like it was brand new. Any ideas?

I have read the forums a bit and have an idea of a few likely solutions but unfortunately I'm a poor college student and I would like to try my best to fix the problem on the first try. Any input would be great, thanks.

-Snake
Last time you changed the oil?

Thank you guys for all the great help! Tim, we're gonna test the relay asap. BV, I changed the oil a few months ago but don't drive it much while at school. Mile wise it's just about due for a change, I'll be doing that this weekend.

Thanks again, I'll keep ya posted.
-Snake

Hey guys, I just wanted to thank you for the help. I tested the GPR using a digital voltimeter and it was indeed shot. I replaced it and the truck now starts great. Thanks again! -Snake

Good to hear you got it fixed.

The beauty of these sites is that you can benefit from what others have been through. When I was new to PSDs, another site like this saved my bacon a number of times!!!

TC