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2002 7.3 crank no start help

1K views 7 replies 4 participants last post by  ArcticDriver 
#1 ·
A friend of mine was driving down the highway and told me his truck would stutter every once in a while. He said it felt like the engine fell off for just a second then would come back up and run. He drove it to my place, about 25 miles to check it out. Of course on the way here it ran fine and we couldn't see any issues with it. When he was getting ready to leave after letting the truck sit for an hour or two, he started it and let it idle. After it ran at idle for a few minutes it just shut off. It started again right away.
A few weeks ago the truck would idle until the temp hit 190 then it would shut off. He got a new IPR valve but couldn't get the valve out so he just changed the electrical sleeve on the valve. The pickup started and ran fine for a couple of weeks. The other day it died on him, so he changed the ICP sensor. It ran again after that.
After it died the other night at my place I changed the while IPC valve for him with the new valve. I did notice the old valve used a 1 1/8 socket, the new one was 1 1/16. Got the new valve in and went to start the truck. It cranked for probably 10 to 20 seconds then slowly came to life and ran. Let it run a while and shut it off, started it again. Again it cranked for 20 seconds or more and started. Let it run for 5 minutes and shut it off. Now it wont start. Even today after it cooled off it wont start. The engine will start spinning fast like it wants to start but it wont run.
I connected my forscan to check it out. The IPR will get up to 65% but the ICP will only get up to 485. When cranking the ICP will bounce between 300 and 450, then will get up to 485 when it starts spinning faster like it wants to start.
I unplugged the ICP but it still wouldn't start.
So, where do I look next? I don't know where he got the IPR so don't know for sure if it is a good one or not. I'm going to change back to the old one to see if it helps. What do I check next?
 
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#2 · (Edited)
Have you checked the engine oil level? May need to overfill it by a gallon and jack the rear of the truck up to check for a cracked pickup tube. It may just be that you introduced air into the system.


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#3 ·
Yeah, the first thing I checked was the engine oil. It is just a little bit above full on the dipstick. I pulled the allen plug on the reservoir, it is full. Cranked the engine with the plug out and oil came burping out.
Tonight I switched back to the old IPR valve and it started fine. Forscan is showing that while it is running at idle the IPR % is at 12.5 steady. The ICP will bounce from 510 down to 440 regularly, once in a while it will dip to 430. So, at idle what should the ICP be at? I always thought it should stay at or above 500 psi. Is it possible we are chasing a HPOP issue?
 
#4 ·
Your ICP and IPR readings at idle are normal.


It's possible you have wiring issues, temporarily fixed when you mess with the connectors, etc. I would check the wiring. Normally a wiring issue would show codes, but possibly not.


If you're not getting a minimum of 500 psi, you may have leakage in your HP oil system. The HPOP is probably the last thing it would be. They're pretty robust.
 
#5 ·
The wiring issue is a possibility. The owner did say it ran rougher on a rough road.
I don't see any oil leakage visible anywhere on the engine. This engine is very clean all around. No grease dirt or oil in the valley, no dirt or oil anywhere else. I will have him keep a close watch for any oil leaks visible.
Today I started it and ran it up to operating temp. The idle when it first started showed the ICP bouncing between 500 and 600. I wound it up to aboiut 2500 rpms and the pressure went up to around 1800 to 2000. When it warmed up the pressure at idle started bouncing down to 430 and up to 550. Revved to 2500 the pressure did not get over 1500.
It is at least starting and running now, so he is going to pick it up and watch it for a while. This is a service vehicle so he needs it back to earn a living.
I had forgot to add, when he got here the other day he had codes P1280, P0381, P0475, P0603 and P1211. I cleared them and the only one that keeps coming back is the exhaust back pressure code. I suspect that is due to the exhaust. The previous owner put a larger diameter straight pipe on it, so I assume that is throwing the back pressure out of range.
 
#6 ·
Change your CPS- it can mimic a myriad of problems.


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#7 ·
The CPS was my next target. I don't have a lot of experience with diesels, but the only other 7.3 I have worked on in the last few years that was the problem. A shop had already changed the CPS but put in a cheap aftermarket part. His symptoms were similar but only when he turned his wipers on.
When he gets here and I have a driver I want to ride on the highway with forscan running to watch his ICP. If that looks good under load at highway speed I will call that good and see if he wants to bring it back to do the CPS.
 
#8 ·
+1 on new Motorcraft/IH CPS.

Its a $35 part and saves customer from having to get towed or drive back to your shop later.
 
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