Hard Start when Warm - Diesel Forum

6_Myles · 11-20-2009, 10:10 PM

I replaced my IPR a little more than a week ago. I was having a slight hit at idle and it cured it for about 3 days. Other than that the truck has ran strong for the last 140k miles. I purchased just the IPR shaft from Dieselsite and I'm using my old solenoid.

It seems that when my truck gets fully up to temperature and heat soaks the engine (especially after parking for a couple of minutes at full temp) it is hard to start, won't hold idle and has a loss of power. Throws a P1211 code off and on too.

Things I've done to try to fix it:
1. Oil is full and clean
2. IPR nut checked
3. IPR connector checked
4. New Gray CPS from Ford
5. Bought Autoenginuity to try and diagnose the issue

What else should I check and what parameters should I monitor with AE to see what might be causing it? Thanks
Myles

6_Myles · 11-21-2009, 12:28 AM

Update with two things:

1. I pulled the IPR out and double checked the O-rings and that the plunger worked. Everything Okay.
2. Noticed a leak coming from my CPS. Pulled it out and the O-ring had been cut off for around 1/3 of the circumference and two of the wires looked to have been pinched and the insulation was cut to the wires. Elec. tapped the wires and replaced the O-ring and everything seems to run now.

Duty cycle on ICP duty cycle didn't go above 40% when cranking or doing about 3/4 throttle runs. ICP Pressure/Duty Cycle/Voltage seemed to track relatively together when displayed in graph mode.

**klhansen** · 11-21-2009, 05:31 PM

With AE, you should check your IPR duty cycle and ICP while idling when cold and then as it gets to full temp. If there's a significant difference, it means that there's a leak somewhere that's getting worse as the oil thins out as it heats up.

Could very likely be injector o-rings. If you can get hold of the adapters to plug off the HPOP hoses going to the heads, you can compare IPR duty cycle with the engine running on each bank (yes, it will do that.) The procedure is to plug off the passenger side hose and check, then replace it and pull off the driver's side hose and install the ICP on the end of it and recheck. A significant difference in IPR duty cycle will tell you which bank is leaking (the one with higher IPR). You can also plug off both hoses and test the IPR/HPOP combination to see if it will put out the required pressure.

Normal idle should be about 650 rpm with around 450 psi ICP and 12% or so IPR duty cycle.

Hope that helps.

6_Myles · 11-21-2009, 10:25 PM

Thanks for the help. Seems to be back to normal all day today while towing the trailer but i'll keep that in mind if it starts to act up again.

A/E is definitely the ticket when it comes to diagnosing problems. It just takes so much of the guess work out of it.

F350_6 · 11-21-2009, 11:00 PM

Did your new IPR from Dieselsite not come with a solenoid? I thought usually the IPR and solenoid were replaced as a set?

6_Myles · 11-22-2009, 08:19 PM

No you can get just the IPR from them. I'm beginning to think it's either the pigtail or the solenoid as it did the same thing on the way home today.

NEWEST ISSUE:
Got the P1211 code again but also P1209. Duty cycle was around 65-70% continuously but the pressure was good. Shut the truck down, immediately fired it back up and everything was back to normal.

I'm beginning to think the new IPR is bad as it was running great w/ none of these issues prior to the new one (except for a small skip/hit at idle only). I already shipped my old back to Bob and was wondering if anyone had any additional advice before I purchased a new one?