96 super duty hard start cold no start hot
 

Hello new to the forum be easy on me. Bought a truck seller said hpop was bad . Did some reading and not sure I believe him. Here's what's going on. Hpop oil reservoir is always full. Truck sits over night and needs to crank a long time to get it to start 10 or more short crank periods. Once it's running it runs rough for a few minutes then cleans out and all is good. Glow plug wait to start all that's good. Once it starts u can shut it off cold and it will restart just fine right away. Once it gets normal oper temp and shut it off it won't hardly start at all. I sniff of either will get it going but just cranking on it; it's almost like it Ramps up in Rpms like it's trying but won't catch on and start most of the time. I unplugged my icp no difference truck still ran with it plugged in or unplugged. Checked the icp pressure at hot start up it only builds maybe 400 psi max until it starts the. Bumps up around 700 and around 2400 at max so if I'm thinking right hat tells me my hpop and ipr are both good and I have a leak down issue possibly blown out injector o ring causing it to loose prime and when the oil gets hot it can't build 525 psi to activate the injectors just by turning the motor over by starter alone? Any help would be greatly appreciated thanks

Just because the wait to start light comes on does not mean the glow plug system is working correctly. You will need to ohm out the glow plugs to make sure they are good and verify the glow plug relay is working. A quick way is to cross the big terminals with a screw driver and see if it makes any difference. Hold it for 30 seconds then jump in the truck and try to fire it up. If it starts quickly then the relay is likely the cause. The stock style relays are known for not being the most dependable. If it doesn't make any difference then move on to the glow plugs themselves.

The hot start issue may be the IPR o rings. The rebuild kit is pretty cheap from international and it is easy to do. How many miles are on the truck and do you know when the last oil change was?

I figured even cold temp in the 80s it wouldn't take that long to fire even without glow plugs but I Tested the glow plugs this morning have power going out to them and shuts off like it should compared to the light. Last oil change done recently within 1000 miles truck has 180 thousand on it.

Classic IPR oring issue

That's a cheap place to start I sure hope it fixes it thank you :) the guy who I bought it from told me the hpop was bad so I got the truck for a steal on a gamble it wasn't nothing major and working on big Diesel engines all my life it just didn't add up seeing that it still builds desired pressure at wot thank you

Sounds like my parts truck purchase. The valve cover gaskets were leaking, and the seller mentioned that was a sign of bad injectors which is why the price was so low.... I just looked at him, said "is that so?", and paid an outrageously low amount for the truck

Edit - disregard.

Ordered on rings thru ford and also ordered an icp sensor I was checking things over and the plug was covered in oil so figured the sensor was going out too. Will keep my fingers crossed everything works in the morning. Ipr sensors hard to remove??

IPR remove tinnerman nut and then the metal cap thing and coil, then unscrew IPR from HPOP with deep socket

Nope. Just remove the electrical connector, spin off the tin nut, remove the magnet portion, then use a deep well socket to remove the rest. Just be easy with the tin nut

Don't you have to pull the fuel bowl too?

no, there isn't much room but it can be done if patient

Removed fuel bowl removed ipr valve and rebuilt it with ford parts put back together and still having the same issue won't start when hot unless a little sniff of either is used. No check engine light and it don't make any difference if the pressure sensor is disconnected or not. Could my ipr valve be bad?

Were you a ke to shake the IPR. If it dont rattle it could be gummed up.