my truck dose not start if its cold or if it has not started in more than 12hr dose any one have any sugestinons

 

Welcome to the site..

It 'will not' start cold, or hard to start meaning extended cranking time..

 

if it is cold will not start untill i have heated it up with propain heaters
if it has been more than 12hrs then i have to refill the upper oil sump and use starter fluid and be getting a jump start at the same time to support the extended cracking time required were talking like 2 to 3hrs of cranking

 

2-3 hours or cranking!

The PSD's need to have a 'minimum' of 500lbs of high pressure oil to start. Almost sounds like you may have more than one issue though. Does it run good once its fires off? or does it stumble and misfire until it finally stabilizes at idle? If so, how long to correct? The early PSD have problems with the injector Orings bleeding, and the cold makes it worse to try and build to a starting pressure if leaking, more so on the engines with some time on them. Have they every been replaced/resealed? How many miles on the truck?

They are also known to fry the glow relay, glow plug circuits on the UVC (valve cover connections) harnesses connectors, glow pugs, and usually you can see a burn/buldge area on the outer most ends of the connector/s if their bad.


IPR regulator can cause a low high pressure oil problem, a weak HPOP pump, but what really needs to happen is to have the cranking pressure checked/verified either manually with a gauge, or can be checked with a DVOM at the ICP, or best viewed with a scan tool to see what the PCM is seeing. Same with a minimum cranking speed, if its not met, the IDM won't fire the injectors. You might try and unplug the ICP sensor (left front of the valley area near the v/cover) to bump up the cranking oil pressure. Might try the EOT sensor(Low/front of the HPOP) to extend the glow ON time if the system is in fact intact. See if there is any improvement in a start. Last, be carefull using fluid on a start assist, if the glow system 'is' working, it can flash back out of the intake..

But if the HPOP oil level empties after sitting, or if it can't build the minimum start pressure, the reason for the loss needs to be found.

 

I have a 91 7.3 with starting proplems took several changes to solve the problem. New glow plugs, enjector pump, glow plug relay, fuel pump, replacement of all fuel return lines, New batterys, engine heater, starter, etc. The glow plugs and glow plug relay made the most differance in warm weather. The enjector pump made another big differance. Then it was figured out that after setting for several hours that the pressure in fuel line was leaking off so then came the replacement of all fuel return lines and the fuel pump, seems the IH motor does not have a check valve to keep the pressure up, Got that information from the IH dealer, they said that they used the fuel pump to maintain the pressure. Hope some of this helps My truck runs like a million bucks now and each change made a differance in how and what proplems were left to figure out. Good luck with your project.