Crank no start (sometimes)

powerjoke4life · Sep 29, 2014

96 7.3 stock motor

The truck will crank but not start, no WTS light (this hasn't come on for a while) no tach movement while cranking, after trying a few times if I go back out there an hour later it'll fire right up. Drive around fine, but may die.

Checked all my fuses for the PCM they all look good.

I think it's the CPS but is there anything else I should check before going to buy a new CPS?

Sent from my iPhone using Tapatalk

Turbtators · Sep 29, 2014

Cps isn't to expensive and its an easy install. Worse case scenario its not the cps then you'll have a spare cps when it does go out. Do you have any check engine lights? Also do you have anyway to check hpop pressure?

powerjoke4life · Sep 29, 2014

Ya thats about what I was thinking, I just know by the time I get the part, get home and put it in Ford will be closed and if I need another part it will have to wait another day. Just wanted to see if there was anything else I could look at before the dealer closed today.

I can check the oil P but it will have to wait till tonight. Would the HPOP go in and out like that? I figured it would either work or not work. If it is sitting why would it start one time but not the next time?

Turbtators · Sep 29, 2014

If you have no tach movement I would think it'd be cps. Only way I would think the hpop would go in and out is if you had a short or bad sensor.

powerjoke4life · Sep 29, 2014

Ok cool, I will get the CPS ordered and try that out. Is there a way to test the CPS?

Im at work so hopefully it starts right up after work and I can get it home to check the HPOP

Turbtators · Sep 29, 2014

Im sure you can check it. I do not know what resistance or voltage would be acceptable hopefully someone can give you that info.

Arisley · Sep 29, 2014

Check the PCM relay.

gnxtc2 · Sep 29, 2014

Also check fuse #22 under the hood, it's for the fuel bowl heater. If it's blown, disconnect the heater.

But sounds like CPS.

Billy T.
[email protected]

jschildm · Sep 29, 2014

Could a no WTS light be IDM fuse? I can't remember what fuse number it is. Perhaps just a short or something in its wiring.

Arisley · Sep 29, 2014

If a fuse was blown, it would not be intermittent.
If a relay is going bad, it will be intermittent.

powerjoke4life · Sep 29, 2014

I checked all the fuses under the hood, I will pull the relay and see if it is still engaging.

powerjoke4life · Sep 29, 2014

Arisley said:
If a fuse was blown, it would not be intermittent.
If a relay is going bad, it will be intermittent.

Good call

Arisley · Sep 29, 2014

Just swap the PCM relay with the blower motor relay.
They are the same in a superduty, I am assuming they are in the OBS.

mandkole · Sep 29, 2014

I used to get a random no start with the OBS. You could start it fine for 50 starts, then on 51 and no matter the situation, it would just crank. You'd stop cranking and rekey it, it would fire right up.