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Discussion Starter · #1 · (Edited)
:dunno: I recently purchased a 99 f-250 7.3 zf6 speed early 99 built in 4/98, it is my third 7.3 been running these trucks for over ten years. The truck bogged down and shut down on the freeway, it acted like the fuel filter was plugging so I changed it out, added some Diesel 911 supplement (in case of bad fuel) and primed it up with the old trick of automatic transmission fluid in the filter bowl. It started up and ran fine for two more days, then I was teaching my Granddaughter to drive the truck and she shifted from 2nd gear to o/d by mistake and killed the engine. It has never started again. Here is what has been done so far: Ran codes with a Snap-on reader and cam position sensor was bad, no surprise there, he also double checked the CPS with another Snap-on tool that showed it dead. Replaced CPS, replaced ICP (it had oil in connector) wore the batteries out cranking the engine so they were replaced and still no start. Oil in crankcase and HPOP reservoir full. Checked fuel pressure with gauge 65 psi after filter, checked HPOP with 5,000 psi gauge pressure builds up to 3000 psi then backs off to 2200 psi and remains there while cranking. No blown fuses, no bad relays, tach jumps up to 400 rpm while cranking, wait to start light comes on and cycles off like it should as do all other dash warning lights. I am going to check ohms on the UVCVH harnesses tomorrow, and buzz test soon. Am I missing anything? I never had problems like this with my other 7.3 it only needed 2 CSPs and fuel filter changes over ten years.:dis:
 

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As far as I understand the IPR is one thing that can cause no start, even if fuel/oil pressures ok from what I understand if it doesn't work the fuel will not get to the injectors, but I am not super experienced with these things. I have been struggling with my truck for a while and replaced lots of parts, which needed replacing, it has improved but still not to my liking. I hope that this helps. Is there any smoke? If none- doesn't sound like getting fuel which would probably lead me to the IPR (it is on the rear of the HPOP(at least on my 95). Hopefully others will help/ offer advice.
 

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Discussion Starter · #4 ·
Update, I pulled out the IDM and did the injector harness ohm test per the GB tech bulletin #103, readings look bad. #2 24.8 ohms #4 4.8 ohms #6 5.4 ohms # 8 5.7 ohms #1 6.9 ohms #3 6.9 ohms #5 0.0 ohms #7 7.3 ohms. This was done with a cheap Harbor Freight multi-meter, which lowest setting is 200 if that means I can divide all the readings by 2 then there is still a major problem with #2 high reading and #5 no reading. Would the failure of those injectors cause the PCM to prevent starting?
 

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The 7.3 PS will run on 4 cylinders, not very well, but they will run. If your HPOP pressure shows 2200 PSI of pressure, then you have more than enough oil pressure to fire the injectors for start. How many miles on the rig? I pull the valve covers off and make sure the injectors are firing while turning over. You will actually see the oil come out of the oil spouts on each individual injector. If you see oil then the injecotr is okay. Also, a buzz test only makes sure the solenoid on the injector is working, it does not mean the injector is working properly. If you have a badly worn injector then the solenoid will not be able to mechanically operate the injector. If you need your injectors rebuilt call Rosewood Diesel. If you have any other questions feel free to PM me on here.
 

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Yeah, but thats about the lifespan of injectors.
 
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