My truck has had unusually long cranking time since I purchased it in 09. After sitting all night or all day when its cold it takes about 5-7 secs to turnover. I got a SG II recently and I have been monitoring the ICP and IPR values. Here's what I got.

Key in start position:
ICP = 0
IPR = 14.4

Cranking motor:
ICP = 65
IPR = 77

I run all OEM filters and caps. The batteries are strong and I test them every six months. The alternator was replaced 5 months ago, and the FICM was replaced two years ago. I'm quite sure that I have a HPO system problem, but I'm not sure were to start. Should I replace the IPR and see what that does? Or should I look some where else?

 

69, not sure what you are reading with icp and ipr. You want to look at psi on the icp and duty cycle % on the ipr. I have an early 04 and have been going through this for the past 3 months. So far I have only found a bad pigtail on the ipr. I also had a battery drain that I hope I have found and fixed. Check the voltage on the ficm, check all wiring and connections around the ficm, icp, ipr. You should have at least 400 psi at the icp and 24-27% duty cycle on ipr during cranking. I have found there are many causes. How are your fuel filters? Do you have good pressure on fuel? Last oil change, what is the level. I know much of this is redundent but I have found to look at everything. Everyone will need more info to really give assistance.
God Bless and good luck

 

My '03 won't crank with less than 500 on the ICP.

 

eagleinms,

The values I gave are in PSI for the ICP & % for the IPR. The FICM voltage is always at 47.5 to 48. I have also checked every wire loom i can find for chaffing and loose connections and I didn't find any. The fuel filters where changed 5K miles ago, and I don't have a way to check fuel pressure.(I don't think that the SG can read fuel pressure?) I just changed the oil last week, so the oil level is good. I've had this problem ever since I bought the truck and it has been very frustrating.

Also, I scan for codes periodically and there are never any to retrieve.

 

It looks like you have a HPO leak

IPR% looks good for Key On Engine Off

Cranking IPR% looks good but ICP is way to low ICP needs a Minimum of 500 psi to run My truck Idels at 640 ICP when up to normal temp

Program the SGII for ICP Volts to

from the sound of it the HPO Bleeds off as it sits with the truck Off and It takes longer crank time to fill the HPO system back up


What Year is the truck???

 

I would pull the IPR and check it first. If the screen is good then you're probably "OK". If not then replace the valve and retest. You might also want to pull the ICP sensor wire and crank the truck to see if a biased sensor is causing your start problem.

 

Cranking is the engine turning over. You can crank it no problem, but the injectors won't fire.

 

Blade35,

The truck is a 2006.

 

You have the Good HPOpump so it shouldnt be that

That year is known for STC Fitting standpipe and or dummey plug issues have you changed any of these parts yet

So It runs just takes some extra Crank time right I beleive its got a HPO leak

When its up to Normal temp 190ECT whats your ICP & IPR% at Idel

 

Blade35,

When idling at normal operating temp 188 ECT, the ICP is 580 and the IPR is 22. Is their a kit that I can buy that has a new stand pipe and dummy plugs? Do you know of detailed repair procedure for this fix?

Thanks

 

With those numbers, you don't have a leak, or at least not anything significant. I have heard of a similar symptom caused by a minor air leak, which allows the HPOP to drain out over night when the truck is parked either nose down or nose up (I forget). Anyway, if it's always nose down slightly where you park it, try turning it around and see if it still does it.

 

It doesn't matter if its nose down, nose up, or sitting flat. It always does it. It will fire up quickly like it should if you start 30 minutes after you shut it down. But after about 2 1/2 hrs the crank time starts to get longer.

 

Those numbers are good no majoir leak BUT

So I take it that right when you first start cranking ICP is way Low and after a 5-7 second crank the ICP will shoot up and start sound about right

If so^^^^^^^^^^ sounds like a HPO seal or maybe even an Injector seal shrinks and bleeds off pressure this might be a Hard one to find

you might even have to air test when Cold IDK

 

Stupid question, what does icp and irp stand for

 

That's what I was afraid of. I'm not too comfortable messing with the injectors. If its an injector seal do I just change out the injector?