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no start 1995 f-250

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i have a 95 f-250 that is giving me a fit.The glow plugs and relay check out ok.The vehicle will start if with a shot of either and runs fine.It however will not start by normal means.The problem is there hot and cold.Icp voltage goes to .54 volts while cranking with a icp breakout harness installed.the resovoir is full.Could this be a internal leak or a weak pump or am i going in the wrong direction.ipr% goes up to 50% while it's cranking.Any ideas would be helpful.fuel pressure is ok cranking. Thanks for any help.

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i have a 95 f-250 that is giving me a fit.The glow plugs and relay check out ok.The vehicle will start if with a shot of either and runs fine.It however will not start by normal means.The problem is there hot and cold.Icp voltage goes to .54 volts while cranking with a icp breakout harness installed.the resovoir is full.Could this be a internal leak or a weak pump or am i going in the wrong direction.ipr% goes up to 50% while it's cranking.Any ideas would be helpful.fuel pressure is ok cranking. Thanks for any help.

.54v cranking won't enable the injectors, which turn on around .8v ICP. What's the IPR command at a hot idle? It should be in the 9-11% range, if it's higher there could be leaks. If you have time, pull the VCs and look for leaks at the top o-ring while idling, they will be very obvious. /forums/images/%%GRAEMLIN_URL%%/laugh.gif Check a fuel sample for oil dilution, which would show the center o-ring leaking.

 

Possibilities:

 

O-ring (top or center) leak (very likely)

Bad IPR

Weak pump (not so likely)

 

If you want to deadhead the HPOP, ground the IPR return while it's idling and see what pressure it builds. It should go to 4100psi or more. (4-4.5v+) This is a very aggressive test though, so don't do it for fun and don't do it for long.

 

Good Luck!

 

 

/forums/images/%%GRAEMLIN_URL%%/grin.gif

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fuel is ok and no signs of oil.ipr% hot idle is 11.33% tried blocking each head's oil line one at a time, still a no start.with the pass side blocked it still showed .54 volts and tried the drivers side but icp was then unhooked so i couldn't tell the pressure but it still was a no start.going to pull the ipr next

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Kevin, your store should have the correct block off tools to enable you to use the ICP to help with diag.... 303-S626 should be the tool number you require...

 

Some shops may not have a decent way of tracking tools in their various boxes... any tool inventory program can be a PITA to set up - but it is something that is vitally important.

 

We use M$ Excel or, your store can try THIS.

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all i can find is the one block off tool and not the one the icp goes in.i found the box ,its just missing, but it still wouldn't start with either side blocked so i guess that leads towards the ipr or pump the best i can figure so far.going back to work tommorow so i will update.

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Cranking RPM's, cranking VPWR, compression test? If the HP pump was dying I would think the IPR% would scroll up higher? Did you try a "test" ICP?

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all i can find is the one block off tool and not the one the icp goes in.i found the box ,its just missing, but it still wouldn't start with either side blocked so i guess that leads towards the ipr or pump the best i can figure so far.going back to work tommorow so i will update.

I remember when i took the 7.3L class, i was told, "if there is a question on the final about a result from a pinpoint test that conclude's either A. replace IPR or B. replace HP pump, and you choose to replace the HP pump B. you will fail this course!!!"

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ipr o-rings fixed truck.thanks for the help.the vehicle would start with either but would not start with the key.i checked the crankcase pressure with a guage hooked to the guage bar earlier in the week.it was ok per specs

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