Have a problem I'm trying to track down and so far haven't gotten anywhere so here we go.

I have an 05 truck, 140k miles, truck has a long crank, doesn't matter if it's hot, cold, plugged in, etc. It cranks for Several seconds 10-15, before it fires off. Sometimes it'll start then instantly die. The whole time, IPR reads 85% and ICP slowly climbs to 300-400 before it finally runs. Once running, it runs beautifully. No injector stiction, no miss, nothing. Truck drives flawlessly, identical to the truck I drive across the country pulling loads with, no smoke, no miss, nothing. All numbers on the scanner look normal as well.

Truck has brand new batteries and cables, brand new oil, fuel and oil filters (OEM) brand new IPR (OEM).

If I turn the truck off, and start it within a minute, it fires right up in half a key turn, runs perfect. If I let it sit for 5-10 minutes, same story, long crank.

The only thing I have come across- is when I perform a key on engine off test with auto engenuity- I sometimes get all 8 cylinders showing injector circuit codes. FICM voltage always says 48, but I consistently get these codes. To me- this doesn't make much sense as I don't have ICP for awhile while cranking regardless.

If I open the oil filter housing, and depress the valve, the housing fills itself within around 2-3 seconds, low pressure oil seems fine, but until right before the truck starts it shows no oil pressure on the dash.

Something to me feels like I have a low pressure oil drainback issue, starving the high pressure oil system of oil, and it drains back down too quickly until it sits and cranks long enough to overcome the loss of pressure- since it doesn't act like an HPO leak at all.

Any leads on where to go next? I have a fitting on order to air test the HPO system, but curious if anything else stands out as well.

 

Sounds like the oil rails on top injectors are draining off as it sits

Stand pipe and dummy plug usual culprits here with injector top seal leaking not as often but should be checked


any recent work besides oil and fuel filters

 

No idea on recent work, truck was purchased this way from auction as a "gas in fuel" insurance job. Drained gas, added diesel, fired right up and sounded perfect, after a few days of cleaning the interior etc, it developed the long crank.

 

I had a similar problem on my ‘04 X 10 years ago. Same symptoms. My fix was ICP. After I replaced it I took the ICP apart. The internal seals leak. That is probably the reason the pressure builds slowly and the connector is coated with oil. Check the ICP connector for oil. If no oil, probably is plugs/standpipes. I have 150K on my X and have replaced the ICP three times.

Ed

 

No oil in the connector, unplugging it doesn't make it starter any faster, I ordered standpipes and dummy plugs and will pull it apart to see shortly

 

Does this have an OEM oil filter and cap?

 

Yes, brand new OEM filter, cap, and the tube in the center. When I initially changed the oil in the truck I broke the tube, and replaced that as well.

 

Sounds like it's taking a long time to build base pressure......you say the needle won't budge right up until it pops.
Could always check the pressure relief valve down by the LPOP.....not a huge task.
I think DTR has a good video on that one.

 

Oddly enough, it actually builds base oil pressure extremely quickly when I pull the cap and crank it over with the starter, just as fast as my other 3 trucks. It just doesn't show up on the dash until it fires, which is really strange to me.

 

High pressure leak can cause base oil pressure problems

 

Tore the truck down yesterday and reassembled today. Checked all injector orings, and replaced dummy plugs and stand pipes. Oddly enough, 2 were the old 10mm (1 stand pipe, 1 dummy plug, opposite sides) 2 were new. The old ones had signs of wear and abuse but were not split anywhere. One of the new dummy plugs had a chunk missing out of the o-ring, but was not broken. All 4 were replaced with new OEM, batteries recharged, oil topped off.

Obviously the truck took a couple long cranks before firing up. Haven't gotten a chance to drive it yet or watch variables, but it doesn't seem to have much improvement. We'll see if a couple WOT pulls clear anything up or not.

All injector nipple/cups looked good when inspected.

I'll re air test again, pull the relief valve, and go from there.

The most confusing part I'm having with the truck is the low pressure oil indicator on the dash. It still shows zero pressure until the truck fires off, which I've heard may be somewhat normal. I know it has plenty of base pressure, I have it side by side with a truck that runs absolutely perfectly, and they both build low pressure oil/fill the housing exactly the same.

 

sorry i posted on the wrong post

 

It can take up to 20-30 minutes to rid the system of air before the truck starts properly. Having weak O-rings on any of the dummies or stand pipes is going to be an issue now or soon enough. Mine looked like they would still seal but they leaked anyway. New dummies solved the problem. It took a 20 minute drive to get it starting properly. Replacing the IPR with a borrowed or new one will be the next step unless you test with air fitting at the IPR location. If you are going to remove valve covers for anything it is worth doing the air pressure leak test to find any problems early. Just takes a minute or two. Inspect the current IPR for torn screen and problems. Don't forget to check those little plugs on the top of the oil rail too. Isn't the 85 percent IPR while cranking indicating HPO leak if you have sufficient low oil pressure?