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Discussion Starter #1
Hi everyone. Thanks in advance. I have a question on the effects of shorted out or wired backwards wires on the IPR. I need to know what could have been effected by this if it happened, please. It is a early 1999 F350 7.3. Crank but no start, no smoke. Thank you
 

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If the wires are shorted out, the IPR just won't work. If reversed, it should still work, although possibly not.
The IPR has a hot wire with key on, and the other wire provides the ground path thru the PCM, which pulses the switch to modulate the signal.
If you think the wires are switched, switch them back and give it a try. You should be able to use a pick to remove the terminal from the connector and swap them without having to splice wires.
 

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The IPR will work if wired either way. It is simply a coil that needs to be turned on an off. I have seen many an IPR harness connector replaced and wired backward will no apparent ill effect other than I find it annoying when that is done.
 

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Thanks Keith.
I wasn't sure if it being DC voltage it would make the coil work backwards (swap north for south on the magnetization). Good info.
I would probably be annoyed with it wired backwards as well. ;)
 

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It's a coil. All it does is create a magnetic field and I have never heard of (or seen) its operation being affected by reversed wiring.
 

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Okay. So it will not short the IDM or the PCM?
It shouldn't under normal circumstances. I doubt even applying 12V to the wire going back to the PCM would cause that. The only way it would happen would be if the two wires were shorted together, and I believe the PCM has some protection built in.
There have been reports however of various circuits (such as the GP control) frying on the PCM.
You could check resistance to ground on that wire going back to the PCM to find out, but your best bet would be to put a scan tool on it and see what codes comes up.
While cranking, look at ICP, IPR duty cycle, Injector pulse width, and engine RPM.
You need 500 psi on the ICP, 14% duty cycle on IPR, 6-8mS (IIRC) on injector pulse width, and a minimum of 100 RPM for the engine to start.
 

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Discussion Starter #8
Okay thank you I am waiting for a scan tool. Should get it Tuesday. If the scan tool does not communicate then it might be the PCM then. That's what it did before. Only it ran since then. I believe that was caused by the wrong scan tool. It wasn't the J1850 or whatever. The one that's coming says it will. We shall see. Thanks again.
 

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Discussion Starter #9
Okay thank you I am waiting for a scan tool. Should get it Tuesday. If the scan tool does not communicate then it might be the PCM then. That's what it did before. Only it ran since then. I believe that was caused by the wrong scan tool. It wasn't the J1850 or whatever. The one that's coming says it will. We shall see. Thanks again.
Wow. This scanner communicated just like that. My ipw was .528, rpm 172, duty cycle on the IPR 14.7. Its the oil pressure that's low at 224 psi. So if I disconnect the ICP that might help it start? Otherwise I need to check for oil leaks or what?

Thank you all for your help. I am in serious need right now. :)
 

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If you disconnect the ICP, the PCM will use default info to control the IPR.
The ICP may be biased, sending a false signal to the PCM, or it's possible it's sending the right signal and you have leakage in the HP oil system that drives the injectors.
Did you record any codes that your scanner read?
 

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Discussion Starter #11
There were no codes. Of course I pulled the battery's one at a time to charge them. So the leak can be any one of the connectors or plugs on the heads or the pump? Am I correct? I cleaned the valley, and yes there is an oil leak somewhere. It won't start now so I can not let it run to find the leak. The high pressure oil braided line looks good at the pump, but I am not sure about the end on the valve cover/head. It moves but I am not sure how much it is supposed to. The turbo has been rebuilt and new seals not to many miles ago. What can effect the pressure that much? Is it normal? If so, I will work on replacing prints and such to avoid this. Thank you.
 

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Discussion Starter #12
Oh, and would bad orings on the injectors cause this? While working on the turbo we had a hard time so I was thinking the connector in the head/valve cover could of been hit or something. IDK.
 

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Injector o-rings would cause a loss of HP oil pressure, but that's more evident when the oil is hot. Typically with leaky injector o-rings, you can start just about normally - maybe a little longer crank time when the engine is cold, but won't start when the oil is hot. You'll have to pull the valve covers to check. If you see oil gushing up around the injector, then you need to pull the injectors and re-o-ring them.

If your valve cover harness connector came loose working on the turbo, there would be a code for that, but physically checking everything you might have touched during that job would be good.

If you try and start it and then check for codes again, it may tell you something.
 

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Discussion Starter #14
I tried to start it no codes. And do you suggest only motor craft orings or is there good less expensive ones?
 

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Discussion Starter #16
I am thinking injectors but then there was oil in the valley dripping down the back of the motor. Is there any trick to start it and get the injectors on just to be able to see where the leak is?
 

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Have you checked the oil level? If it's too low, there won't be oil getting to the HPOP. Check the back side of the HPOP as well for leakage. There's a small hex plug that's sealed by an o-ring. If that's leaking, it could cause low HP oil pressure. Pretty easy fix, with a new o-ring and threadlocker.

Injector o-rings should come from Ford, International, or Alliant (the OEM for both Ford and International). Not something you want to cheap out on. IIRC they'll run you about $9-10 per injector.

Dieselorings.com is a good source.
 

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Discussion Starter #19
So what I am learning is just the slighesr leak can cause the oil pressure to drop. Am I right? I am thinking the EBPV and I was going to delete it when I did the turbo too.
So I am changing the prints and deleting the EBPV since I took the butterfly out on rebuild. Do you think a pipe plug will plug the EBPV?
Sorry I think I just need reassurance. Lol
 
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