its my old man's 99 powerstroke. we've got a no start condition here. just cranks and cranks. we've got fuel cause we got smoke. and if you crank on it, sometimes it will try to fire a little bit but that's it, just a little stumble. and recently he had new batteries installed and had the cam position sensor replaced on recall, all done at the dealership. he said after he had all that done, he made about a 100 mile trip, it sat for about 2 days, and then the next time he tried to run it, no start!

so what kinda theories we got here? i've got a few of my own but i won't mention them cause i don't wanna pursuade anyone

 

plug fuse?

 

bad sam sensor, right out of the box. Have had it happen a few times so far. Even had a bad one from cummins last year. it happens.

I can see some guru goofing up a wire somewhere, but I would go with the CPS first

 

well i was thinking of just replacing it for him this time, can you guys tell me how difficult it is and the position of it on the engine?

 

How cold is it where you are when you tried to start it?

Tim

 

Cam position sensor, a friends on mine has a 7.3 and got a new one under recall, like a week and half later it crapped out, his orginal one had like 100k before it craped out.

 

oh about 40-45*F

 

Ok, a CMP will very rarley, (almost never) cause a no start condition on a 7.3 psd after cold soaking, esspecially after sitting a couple days. It will however cause stalling and lack of power and delayed/no starting after initial start and run for a while, (almost to operating temp). I think you have a glow plug issue, there could be several issues with the glow plug system. The white smoke is the key here.

Take a volt meter and check for 12v across the g/p relay, set the meter up then have someone else turn the key to the on position so the wait to start light comes on, you should have 12v across both side of the relay, if you only have power on one side then susupect a faulty relay, power on both sides then on to step two, post what you find on the relay.

Tim

 

Just plug it in for a couple hours and see if it starts. If it does then you have a GP issue. Also if the CPS causes a no start then the Tach most likely wont be moving while cranking.

 

Whats your oil pressure gauge do when you try and crank it?

 

Several items to check. Already mentioned is the CPS and the glow plugs and relay.
Also check the injector harness. Ford has had issues with chaffing with the harness.

MikeyB

 

i'll try that tim and let you know tonight

we do have oil pressure, that's one thing i did think of

big bully, i'm thinking that the tach was not moving while cranking, just FYI

 

The tach usually does not move very much untill the engine fires, you might see a small amount of needle bounce but not enough for a diagnosis, a scanner will read the cranking rpm.

As BigBully stated, plugging it in for a while and then starting it is a good way to isolate it to a glow plug circuit issue.

700-800 oil psi needed to fire and idle that engine, around 3000 oil psi at 2,500 rpm for wot operation.

Good luck and keep us posted,

Tim

 

I had a 96 250 and I was in Chicago when the glow plug relay went south on it, did the same thing that your dads truck is doing now. Almost possitive that it is the relay look under the cover towards the front find the relay and see if the terminals are loose if they are it's crapped on you. Also like posted earlier if you plug it in you should be able to crank it. If you don't feel like replacing it right now you just have to plug it in if it's going to sit and the engine cool off

 

ok everyone, i plugged it in while i went to work, when i got off i went over to his house, cranked over the truck, and if fired right off! so, now on to the relay, BUT i cannot figure out which one/where it is! looked in the owner's manual, it don't say crap about a "glow plug relay"

can someone please tell me exactly which one/where it is?