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Discussion Starter #1

Is this normal sounds for a 7.3 powerstroke is it knocking. It has been just dying going down the drive it over and hour never died once. Got in to take a ride it died started right back up.
Drove down the road wait start light came on then when you press the gas nothing happened then it took off but didn't die.
Turn into the driveway and it just died again then started right back up. Any ideas I changed the oil filter, oil,fuel filter, icp sensor, gpr ,cps sensor, new battery terminal cables. It sat the other day and die while idling it does have a fuel leak would that cause it to die . Just need some help.
 

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Sounds pretty normal to me. What's the fuel pressure while cranking (minimum is 25 psi @ minimum crank speed of 100 rpm)? If you can measure it while idling, what the pressure (should be around 50 psi)? With the WTS coming on while driving, it's looks like an electrical problem to me. Was the new CPS a Motorcraft part or an aftermarket part? Cheers!
 

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Sounds like my truck before I replaced the cps (with another OEM). Do you have access to another 7.3 to verify if the existing CPS is okay?

Sent from my Armor X5 using Tapatalk
 

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White '99.5 F250 SD XLT 4x2, 7.3PSD, 6spd, SuperCab, Short Bed - purchased Oct'05
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Sounds like my truck before I replaced the cps (with another OEM). Do you have access to another 7.3 to verify if the existing CPS is okay?

Sent from my Armor X5 using Tapatalk
I used to think that these either worked or they didn't, but I been reading on forums that this may not be the case. Seems that some are acting erratically before complete failure. I've lost two for sure, completely quit, and maybe a third, engine abruptly faltered for just a second while pulling out into traffic. The jury's still out on that, I just replaced it today.

PS: If you own a 7.3 you should have a spare in the truck at all times!

Have you checked the driver's side engine wiring harness as it bends over the valve cover for rubbing? If not just wrap a non conductor around it at that location. Even if not the problem it's good insurance.
 

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Discussion Starter #5
Sounds pretty normal to me. What's the fuel pressure while cranking (minimum is 25 psi @ minimum crank speed of 100 rpm)? If you can measure it while idling, what the pressure (should be around 50 psi)? With the WTS coming on while driving, it's looks like an electrical problem to me. Was the new CPS a Motorcraft part or an aftermarket part? Cheers!
I don't have anything to measure the fuel pressure.
I am about to do a fuel bowl delete on it . The cps is the Motorcraft version c dark gray one
 

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Discussion Starter #6
I used to think that these either worked or they didn't, but I been reading on forums that this may not be the case. Seems that some are acting erratically before complete failure. I've lost two for sure, completely quit, and maybe a third, engine abruptly faltered for just a second while pulling out into traffic. The jury's still out on that, I just replaced it today.

PS: If you own a 7.3 you should have a spare in the truck at all times!

Have you checked the driver's side engine wiring harness as it bends over the valve cover for rubbing? If not just wrap a non conductor around it at that location. Even if not the problem it's good insurance.
I will check the wiring harness because the other day I closed the drivers side door and it shut off.
It has a ts6 tuner in it would be causing issues?
 

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I will check the wiring harness because the other day I closed the drivers side door and it shut off.
It has a ts6 tuner in it would be causing issues?
I can't speak to tuners, no experience, but any loose connection is a problem. Start simple, don't let yourself jump to high dollar fixes. I've read where 80% all issues are wiring. Only 20% are hardware related. Early in my 7.3 ownership I was warned that a leaky windshield is a problem for our truck's computer, especially in the winter when melting snow will cause water to run up hill under the bottom at the dash area, then drip onto inner firewall components.
 

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If it has a chip, physically remove it and see if the problems stop or until the issue is fixed. Cheers!
 

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I agree with Patrick remove the chip been there done that.
 

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Discussion Starter #10
I agree with Patrick remove the chip been there done that.
I know the previous owner ran it on the high idle tune . I put it back to stock tune and that when the problems started would that have anything to do with it?
 

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Chips with bad contact (or even just the chip going bad) can cause all kinds or weirdness. That's why we almost always recommend physically removing the chip as a first course of action when problems arise. That at least gets it out of the equation. Cheers!
 

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I know the previous owner ran it on the high idle tune . I put it back to stock tune and that when the problems started would that have anything to do with it?
Years ago I had a crank no start issue even when I put my bully dog chip back to stock it still would not start. My mechanic told me to physically, unplug the chip and try to start and she fired right up. Chips are electronic and can cause no start or driveability issues when they have a loose connection or go bad which is why I always recommend to physically, remove them until you figure out what is causing the problem.
 

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Discussion Starter #13
I know the previous owner ran it on the high idle tune . I put it back to stock tune and that when the problems started would that have anything to do with it?
Chips with bad contact (or even just the chip going bad) can cause all kinds or weirdness. That's why we almost always recommend physically removing the chip as a first course of action when problems arise. That at least gets it out of the equation. Cheers!
So I started the truck today moved the chip wire and it died .. the chips wire was smashed between the parking brake and the panel. Then I look at the contacts they really need clean
 

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I hope you didn't move the chip while the truck was running. You can easily fry the PCM doing that. The key should be nowhere near the ignition when messing with the chip. Cheers!
 

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Discussion Starter #15
I hope you didn't move the chip while the truck was running. You can easily fry the PCM doing that. The key should be nowhere near the ignition when messing with the chip. Cheers!
I did so if I fried the pcm guess I am buying a new unfortunately. Will find out later today
 

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Hopefully, you didn't fry the PCM. Anytime you are messing with the chip and PCM it is always a good idea to disconnect the batteries. Make sure the wire you found pinched is not broken also, make sure the chips connection is good and clean then see how the truck does if it is still doing the same thing completely remove the chip and see how it does.
 

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Discussion Starter #17
Hopefully, you didn't fry the PCM. Anytime you are messing with the chip and PCM it is always a good idea to disconnect the batteries. Make sure the wire you found pinched is not broken also, make sure the chips connection is good and clean then see how the truck does if it is still doing the same thing completely remove the chip and see how it does.
I took the chip out truck is quieter and runs smoother
 

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