Truck Randomly Dies After 20 Min Of Running Wont Re Start For 30 Minutes

[boxathey]

Hello Im working on my uncles 2002 F-250 7.3 zf-6 4x4 , his truck starts right up runs great for about tenty thirty minutes. then it will die. truck will turn over really fast but wont start. about an hour later it will start right up and run perfect starting the cycle all over again. I changed the cps twice asuming that was the problem. It didnt seem to help. (twice because i thought the first one was bad). I plugged my Scan Gauge II in and found when the truck was runnig everything looked perfect. when it would stall out and not start back up this is what I found. IPR = 65 %, ICP = 161 PSI, I know the engine needs 500 PSI to start. I was going to buy both a new IPR and an ICP but i was hoping to get an explanation of what is happening. I think the IPR is some how sticking open when the vehicle gets hot. I dont think thier is a bad o-ring on the ipr because when the truck is running normally i get roughly 7-14% IPR and 750-1500 PSI ICP. at idle/slow driving. At WOT 30-35 % IPR , 2000-2500 PSI ICP. I guess it could be just a bad ICP mis reading when the engine gets hot. and not showing actual. ICP. i havent tried unplugging the ICP yet.

Thanks Guys

 

[79jasper]

You may also try pouring cool water on the HPOP when it stalls out. Could be the HPOP going.
Make sure the tin nut on the IPR is tight.


Sent from my iPhone using Tapatalk

 

[OLDBULL8]

Actually had the same type problem on the 99, but that was the UVCH connector coming loose under the valve cover. Some place I have the IPR and ICP perdels. Will post if I can find them.

 

[OLDBULL8]

See if I can transfer them here. I can't show the EA readouts, but below info may help.
You should get a 1211 code ifor the ICP IPR malfunction.

1. Verify Fuel and Oil Quality
a. Oil should have < 5000 miles
b. Minimum CI-4 rating
c. Level should be within hash marks on dipstick
2. Verify Fuel Pressure
a. 20psi at idle minimum
b. 30-70psi at WOT with full load
i. If in park/neutral at WOT expect 26 – 28 psi
3. Check Oil Level in HPOP reservoir
a. Should be within 1” of the top
b. Hex key plug on right top of reservoir
4. Check ICP Sensor
a. Key On Engine OFF
b. ICP should = 0
i. If not replace ICP
5. Check for Oil Aeration
a. In Park/Neutral Hold vehicle at WOT for 3 minutes
i. If ICP increases above 1250psi change engine oil
6. Check IPR Duty Cycle Under Load
a. Drive Vehicle at WOT under full load
i. Short burst is fine excessive speed is not needed
ii. If IPR Duty Cycle increases above 65% Replace IPR Valve

 

[boxathey]

Thank you, excellent, detailed instructions I'll do all of the above this weekend and post my results .

See if I can transfer them here. I can't show the EA readouts, but below info may help.
You should get a 1211 code ifor the ICP IPR malfunction.

1. Verify Fuel and Oil Quality
a. Oil should have < 5000 miles
b. Minimum CI-4 rating
c. Level should be within hash marks on dipstick
2. Verify Fuel Pressure
a. 20psi at idle minimum
b. 30-70psi at WOT with full load
i. If in park/neutral at WOT expect 26 – 28 psi
3. Check Oil Level in HPOP reservoir
a. Should be within 1” of the top
b. Hex key plug on right top of reservoir
4. Check ICP Sensor
a. Key On Engine OFF
b. ICP should = 0
i. If not replace ICP
5. Check for Oil Aeration
a. In Park/Neutral Hold vehicle at WOT for 3 minutes
i. If ICP increases above 1250psi change engine oil
6. Check IPR Duty Cycle Under Load
a. Drive Vehicle at WOT under full load
i. Short burst is fine excessive speed is not needed
ii. If IPR Duty Cycle increases above 65% Replace IPR Valve