ICP too high?

bri_grogs · May 20, 2015

I'm working on a hard start and occasional no start only when the engine is hot. Truck is a 2005 with stc fitting, dummy plugs, and stand pipes done 4k miles ago. Injectors are new 4k miles ago as well, they're aftermarket Warren 155/30s.
When the engine is cold the ICP pressure is 35 KOEO and 1000 idling. When the engine is hot ICP pressure is 90 KOEO and 800 when idling at temp. These numbers are from my insight CTS, and seem to be higher than what I read they should be. Is this causing my starting issue, and what would be the recommended course of action short of air pressurizing the hpo system?

bri_grogs · May 25, 2015

Gunna add some more info in the hopes I can get some of your guys' thoughts.
When the engine is hard starting IPR is right where it should be; in the 30's.
In addition to a longer than usual crank when the engine turns over it runs on less rpm's than it should for a few seconds, and you can put the pedal to the floor with no increase in rpm.
For the first time today (it happened twice) while cruising I was able to apply the gas with no immediate increase in rpm or boost, and then several seconds later the power came on all at once as if the truck down shifted, but I don't think the trans actually shifted. I could be wrong about that.
ICP doesn't have any oil on/ in it. I'm going to pull the IPR valve to check for a broken screen later in the week when I have the socket, but IPR values seem fine on my monitor.
When the issue was just on hot starts I was thinking that I need to check the oil system for leaks, but since it now occasionally acts a little funny going down the road should I be looking at something different?

a2elvis · May 28, 2015

Any tuner/programmer on the truck at this time?

swinky · May 28, 2015

Sounds like the ipr is bad. If it's hard starting the ipr should be maxxed out.v

bri_grogs · May 28, 2015

The truck has super panty dropper on it. After I made this post I realized tuners will bump up ICP, but does that explain why ICP is 90 when the engine is hot and off? Shouldn't there be no pressure in the system?

bri_grogs · May 28, 2015

swinky said:
Sounds like the ipr is bad. If it's hard starting the ipr should be maxxed out.v

I thought the opposite, wouldn't the IPR be bad if it was maxed out? Even when the truck is hard starting IPR stays in the 30s. Doesn't this mean the truck is not struggling to build oil pressure?

equalizier · May 28, 2015

that depends which icp sensor you are using.If you are using the 03 icp it will read 20-30 psi higher.I have seen the 04-07 icp register a little but not much and if I'm not mistaken go to zero when the koeo.

bri_grogs · May 28, 2015

KOEO my ICP reads 35 when cold and 90 when hot. I have confirmed this multiple times. The truck is an 05 so I assume the sensor is from an 05, I've never changed it atleast

equalizier · May 28, 2015

Is the sensor black or brown with a metal casing

equalizier · May 28, 2015

What could also be happening is the black"drain back" valve could be bad and not holding oil in the oil res.When the truck starts that hpop is wanting all the oil it can get and if there is no oil in the oil res then your pro longed start begins.You can take oil cap off and hold an extension down on the valve "black" and see if it will hold or does it leak back down.If you are having to fill the oil res time after time there is your pro longed start.

You could also check the ipr to see if there is trash that got through in and behind the spring causing it to barely stick open.You can take ether and clean it real good and push down on the valve in the ipr and clean it with some compressed air.

bri_grogs · Jun 5, 2015

After looking at the IPR someone recommended to me to change the ICP sensor and that was the issue

willholl79 · Jun 5, 2015

bri_grogs said:
After looking at the IPR someone recommended to me to change the ICP sensor and that was the issue

Hmm. Good to know. I have been having occasional crank no starts as well. I replaced IPR, and high pressure oil looks good according to AE. Ficm also checks out. One particular day the truck sat all day and wouldn't start, I unplugged ICP sensor and no change, so I ruled that out.

It has only acted up once since I replaced IPR so I am leaning towards electrical issue. I am also gathering parts to run a temporary fuel pressure gauge to watch that.

Once started, the truck runs fine.