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Discussion Starter · #1 ·
I have recently been working on a 1995 f250 with the 7.3 in it. I just changed the valve cover gasket, but now I get a crank no start. White smoke comes out of the exhaust and it starts for just a second then shuts back off. I also recently replaced gpr. The truck lost quite a bit of oil because of the valve cover leak I have not yet re filled it but plan on changing it later this week.

Thanks
 

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How long are you waiting before cranking it over? Note that the WTS light is just a reminder to wait and does not reflect how long the glowplugs are active (about 1.5 minutes after the key is turned to WTS). Try waiting an extra 30 seconds before cranking. Also get the oil to the correct level. You can do the following tests to check the glowplug /injector wiring:

To check the injector/glowplug wiring: From each valvecover gasket connection's outermost pins (2 per connector) to ground you should get 0.1 to 2 ohms (indicates good plug and wiring). From each valvecover gasket connection's center pin to each immediately adjacent pin, you should get around 3 ohms (indicates good injector solenoid and wiring). You should not get any continuity from any of the outer pins to the 3 inner pins (indicates no shorts between injector and glowplug wiring). You should also get 0 to 1 ohms from each of the external harness connectors outer pins back to the Glowplug Relay's large terminal on the GP side (indicates good wiring from external connections back to the relay).

To check the glowplug relay (GPR), measure the voltage drop across the GPR's large terminals. While the GPR is active (up to 1.5 to 2 minutes after the key is turned to Wait-to-Start) put your meter leads on the large terminals (one lead on one large terminal and the other lead on the other large terminal). This measures how much voltage is being "lost" across the relay. A reading of 0.3V or more indicates a bad relay. Also, check the relay’s control wires (smaller wires) disconnected from the relay for battery voltage at the Red/Light Green striped wire and ground at the Purple/Orange striped wire (check both when the key is turned to Wait-to-Start).

Cheers!
 
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1995 Ford F250 7.3l Powerstroke, Extended Cab LB
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Could be as simple as a failing CPS. Haven't had any no-start issues with my OBS yet but I replaced the CPS anyways because it's one of the 7.3's many achille's heals and if it fails will leave you in a no start situation. It's also only a $15 part and relatively easy to reinstall, so a good place to start. Also a valve-cover gasket leak will likely leave your oil pressure to low on start-up as the HPOP creates a greater amount of pressure upon ignition and if there's a leak that's not only reducing pressure but making a mess it's kind of an obvious place to start no?

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I have recently been working on a 1995 f250 with the 7.3 in it. I just changed the valve cover gasket, but now I get a crank no start. White smoke comes out of the exhaust and it starts for just a second then shuts back off. I also recently replaced gpr. The truck lost quite a bit of oil because of the valve cover leak I have not yet re filled it but plan on changing it later this week.

Thanks
Top off the oil and make sure the fuel bowl and HPOP are full before cranking.
 

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Discussion Starter · #5 ·
Could be as simple as a failing CPS. Haven't had any no-start issues with my OBS yet but I replaced the CPS anyways because it's one of the 7.3's many achille's heals and if it fails will leave you in a no start situation. It's also only a $15 part and relatively easy to reinstall, so a good place to start. Also a valve-cover gasket leak will likely leave your oil pressure to low on start-up as the HPOP creates a greater amount of pressure upon ignition and if there's a leak that's not only reducing pressure but making a mess it's kind of an obvious place to start no?

Regards,
 

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Discussion Starter · #6 ·
I changed the vcg and it hasn’t started since then I think that is what started the problem. I don’t have a chance to work on it until Friday afternoon but when I do I will change oil (fill it up). Can it being 2-3 quarts low cause the truck to not start?
 

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Not sure as I've never let it get that low. My 94 started without issue on12 quarts (2 quarts low). This was when the owner's manual incorrectly stated 12 quarts and they also had the wrong dipstick in it as well. Inspect the fuel bowl wiring harness to make sure no wires are shorting together (fuel leaks turn the insulation to goo). Cheers!
 

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1995 Ford F250 7.3l Powerstroke, Extended Cab LB
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I changed the vcg and it hasn’t started since then I think that is what started the problem. I don’t have a chance to work on it until Friday afternoon but when I do I will change oil (fill it up). Can it being 2-3 quarts low cause the truck to not start?
 

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Discussion Starter · #11 ·
The truck is started after cranking for a long while but I now have a check engine light and little knock. Could this be cause by temps of 15-20 degrees F. Would it have stopped if I let it warm up?
 

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I changed the vcg and it hasn’t started since then I think that is what started the problem. I don’t have a chance to work on it until Friday afternoon but when I do I will change oil (fill it up). Can it being 2-3 quarts low cause the truck to not start?
No, ...the oil pickup is in the bottom of the pan, so 3 or 4 quarts in there would run the engine -- the engine system has no way of knowing how much oil is in the pan.

With that said, running an engine low on oil is bad practice -- the oil is in there mainly for lubrication, but also for cooling -- so, keeping the level up to the mark is recommended
 

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I changed the vcg and it hasn’t started since then I think that is what started the problem. I don’t have a chance to work on it until Friday afternoon but when I do I will change oil (fill it up). Can it being 2-3 quarts low cause the truck to not start?
Measure the ohms like @Patrick Feeley mentioned in post #2 -- and check for harness damage around where you moved the harness -- also disconnect the fuel bowl heater, you do not need this, and it can short out and cause no start problems -- the heater is unnecessary unless you are way up north
 

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Discussion Starter · #14 ·
The truck runs, ur seems like it is misfiring with a check engine light. If I unplug the back vcg harness the check engine light turns off but runs just as bad. I can’t even hit 40mph and power is very very low.

Thanks
 
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