[briancbk]

Thanks in advance for reading this.

I purchased a non running truck. I have a replacement engine, but I would like to hear the old one run to verify the components that I need to re use are in working order. I have been playing around with it for a while, but now I need to get serious and get it done. The truck makes no attempt to start at all during cranking. The HPOP res runs dry during cranking. It has a new LPOP, cps, starter, and batteries. Fuel filter is new, and filter housing fills with fresh fuel. After cranking the engine and refilling the HPOP res multiple times, I purchased a new IPR. I turned the key to see what would happen and it started and ran immediately, even without filling the HPOP res. It ran very good for 30-45 seconds and then died again. It will not start back up. My thinking is that the new IPR was in a different position than the old one, and it allowed the high pressure oil to flow into the head and fire the injectors. I think this means my HPOP is putting out enough pressure for the engine to run, but the IPR valve is staying closed? What tells the IPR valve to open or close? Would this be the IDM?

The original problem with the engine was a turbo shaft failure probably due to high egt's. It is possible that metal from the turbo grenade has made its way into the intake and oil passages of the pedestal, but it sounded so good for that one minute. I would like to hear it one more time.

I paid a ford tech to come hook his scan tool up to it. It was a waste of 100 bucks. He told me the engine was shot and it needed to be replaced.

Any help is greatly appreciated.

 

[tinman13kup]

If the HPOP reservoir is not filling, you have an issue with the LPOP, the pickup tube, or a massive internal leak. That's assuming you have enough oil in the pan.
The IPR is controlled by the PCM, and is measured in duty cycle. It doesn't stay open or closed, but is cycled open and closed until the desired pressure is reached, which is read by the ICP. You can remove a valve-cover and observe oil pulsing out of the spout on the top of the injectors to see if they are firing.

 

[briancbk]

re

thank you for the reply. Any idea why it would start and run normally for 45 seconds right after the new ipr? There is no oil coming from the injector spouts during cranking, but there was when it was running.

 

[Bill1013]

Disconnect the IPR then try to start, the PCM will take care of the oil pressure. If then it runs, look for chafed wireing in the harness were it could rub, seems to be a common problem. You have to attain 500 psi oil pressure to fire the injectors, also the cranking has to be fast enough, watch your tach when cranking, should be 500 RPM or above. I assume your oil level is OK. These engines pump a hugh volume of oil, if it is real low you could be sucking air.

 

[tinman13kup]

Disconnecting the IPR will ensure a no-start/no-run. I think he meant unplug the ICP, which sometimes can go bad. It is what tells the PCM the pressure, and the PCM adjusts the IPR accordingly. If the ICP is biased, the IPR may not be commanded to build enough pressure.

If it ran for those 45secs then died, you need to look for what ran out. Oil in the HPOP? Fuel pressure? You need to make sure the fuel pressure is above 30psi to start, but it really needs 60 to run right. If the HPOP reservoir is running down, that's the problem.

 

[briancbk]

OK, so the pcm and IDM are not the same thing right? I tried it again with an IPR from a running engine and it did the same thing. It started and ran again for about 30 seconds and then turned off. So something has to be sending the wrong info to the IPR and it lowering the pressure to the injectors. Any way to troubleshoot the pcm, or do you just replace it with a known good one? Tried cranking it again with the ICP unplugged and no change. Just cranks and cranks. the engine is spinning faster than my last 7.3, as it has a new starter and two new batteries. I am not seeing the tach needle move much, just a twitch. It has a new ford CPS in it.
thanks again.

 

[tinman13kup]

It doesn't appear to be an issue with the IDM, PCM, IPR, or ICP. They are working. Is the HPOP reservoir going empty? Do you have fuel pressure? It really sounds like you are either running out of fuel or running out of oil in the HPOP.

 

[briancbk]

The hpop has always run empty during cranking. ( since I have had the truck). overfilling the crankcase and a new melling high flow oil pump did not help.

I dont mind changing the engine to the replacement one I have. I just kind of wanted to make sure the IDM and PCM were good so I am not trying to figure out why the new engine wont start either. I just couldnt understand why it would run for a while even on an empty HPOP res after only changing the IPR.

 

[briancbk]

Just for kicks, how do you test an HPOP? Should I cap the high pressure lines going to the heads one at a time to see if I have a problem in one of them? Can I do a manual pressure test with a gauge somewhere?