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Discussion Starter #1
1995 F250 XL ZF5 7.3l PSD. Turns over fine, wait to start light won’t come on, fuse #22 is good, bowl heater unplugged, I think I hear a relay click when key is turned on. It will not start without a sniff of something like a dab of gas on a rag or ether. Once it’s running it sounds healthy but has little to no throttle response and stalls really easy when trying to take off in 1st or reverse. I’m thinking PCM but not sure. Any advice will help. Thanks in advance.
 

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I would check for reference voltage that is supplied by the PCM. You can check for the voltage with key ON, engine OFF (KOEO) at any of the sensors that use it (ICP, EBP, BARO, TPS, MAP, CPS) at the Brown wire with White stripe at any of those sensors. If it's not there, you could have a shorted sensor or a wiring problem in the reference voltage circuit. You could also disconnect each of those sensors one at a time and see if the WTS light comes on when KOEO. For a more thorough check, see the attached. You'll have to either probe through the wiring insulation or get to the pins through the backside of the PCM connector to check if you don't have a breakout box. Cheers!
 

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Discussion Starter #3
I’ll check that out first chance I get. I just bought the truck not running with 152,000 miles on it for super cheap and don’t know it’s history. Thanks for the reply Patrick, I’ll let you know how it goes!
 

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Discussion Starter #4
Wait to start light is now working. IPR and fuel bowl wires were all stuck together and junky rewired it and completely eliminated the fuel heater wires. New batteries, new GPR cranks fast as heck but will not start. Injectors aren’t spitting oil with or without ICP unplugged. Haven’t been able to get a test gauge set up to check HPOP pressure. Reference voltage is all good. Kinda lost now 🏼
 

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Check the HPOP Reservoir level and make sure it is not lower than 1/2" from the top. I would ohm the IPR coil and make sure that it is not open. Check the voltage at the IPR with key on (engine not running). Cheers!
 

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Short answer = yes

Check the voltage at the IPR connector with it disconnected -- if you want take a small size paper clip, straighten out one end, and slip that "probe" alongside the insulation from the rear of the connector -- it should slide in and touch the terminal -- you can then test voltage with the connector hooked up

Helps if you polish(round) the tip of the homemade probe to help it slide in easier and not damage the insulation
 

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Discussion Starter #8
Checked IPR voltage and it’s good, also have a ground when key is on. Pulled one of the 5/8 plugs out of the oil rain and absolutely nothing came out. No pressure? Stuck IPR? Crapped out pump?
 

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Is the CEL illuminated? You may need to get a scanner on it to see what ICP and IPR Duty Cycle are doing while cranking. Do you know if you have good lube oil pressure? Cheers!
 

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If stuck open oil will be directed back to the crankcase. Cheers!
 

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Remove the ICP sensor and crank the engine over -- should squirt oil out, that will let you know if the hpop can pump oil

Fuel pump running?

Need a monitor to see what the PCM is reading -- Torque Pro , Forscan or others
 

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Discussion Starter #15
OBS. Mechanical pump there. I’ll try that with a plug out of the rail. It won’t start or hit at all with ICP unplugged
 
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