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03 7.3 overhaul now hard warm start

2K views 9 replies 3 participants last post by  robdog 
#1 ·
2003 f-550 7.3 I did bearings,rings, reman heads from south Houston engines, 30% over reman on my injectors from diesel injectors so cal. after hard warm start issue I pulled valve covers and had one injector leaking oil from the top oil ring. pulled and noticed the bore was not real smooth so I cleaned up the surface installed new orings the visible leak quit but same start issue. I replaced the icp sensor, rebuilt the injector control pressure regulator the hpop is a reman that was in truck when I bought it used.

Today I unplugged the icp sensor while running and it didnt change anything but gave a check engine light.
Any ideas Im thinking injector orings might be losing oil pressure to the into the fuel end, I am seeing a bit of black and blue smoke when I step on it hard. It does have a ts 6 pos chip. I would rather not have to take it into a shop but thinking I also dont want to just start throwing money at it.

Thanks for any help!!
Rob
 
#2 ·
So, the easiest first step would be to monitor the IC pressure and IPR duty cycle while cranking. If you're having trouble building 500 psi of pressure, then you've got a high-pressure oil problem. O-rings would be a logical place to start if nothing else was changed on the engine.
 
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#3 ·
Ok so I pulled and replaced all injector orings, no nicks cuts or anything. Replaced the hpop with a known good one, rebuilt pressure regulator and still having the same problem. Cold start 700 psi @ 39% Hot start 366 psi @ 65% with no start. Yesterday driving got up to a max of 3418 psi.
I did notice when I pulled passenger side injectors it drained the hpop oil reservoir into cylinders and the driver side didn't do that.
Im lost thinking either a bad rebuilt injector leaking internally or a bad head somehow. Those are the only thing that were changed in the rebuild ( different heads rebuilt my injectors)

Thanks for any help, Rob
 
#4 ·
The engine requires 500 psi to fire the injectors. There is a test to block one side at a time to isolate which bank is responsible. Still would have to narrow down to which injector. No way I can see the head itself being bad.


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#5 ·
I'm going to try unplugging the injectors and crank engine to see if any are dumping oil out the deflector.
Thanks!

From Swamps:Unplug injector connectors at both valve covers
- Crank the engine
- Observe spill spout of the injector and top of injector bore for oil leakage.
(No oil should be coming from the spill spouts or around the injector)
- Replace injector if oil leaks from spill spout or o-rings if leak is from injector bore.
 
#6 ·
I unplugged all injectors 7 of 8 have oil coming out the spill spout with #1 being the worst and that's with the engine cold. So not happy but at least I may have found my problem.
Thanks again,
Rob
 
#7 ·
I unplugged all injectors 7 of 8 have oil coming out the spill spout with #1 being the worst and that's with the engine cold. So not happy but at least I may have found my problem.
Thanks again,
Rob
Sounds like it's time for a discussion with your injector rebuilder about warrantying those injectors. Hopefully they stand by their work.
 
#9 ·
Well they tried to tell me only the worst one was my problem, I gave them 7 and kept the one that didn't leak and told him I didn't want to do it again. Hopefully they go through all of them, tried to tell me some leakage is normal.
 
#10 ·
Ok they repaired one and said the rest were good, so far seems to be starting much better. I'm still not happy that 7 of 8 were leaking but they said it was normal. Time will tell.
Thanks!!
 
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