02 hard start when warm

[HaysKSFirefighter]

Alright so my truck has the basic mods, intake, exhaust, cales tunes, srp1, gauges, etc.

For about the last 7k miles I have been getting a weird issue that my truck is hard to start when its warmed up. It will turn over just fine but doesn't seem to catch for a while.

It has a new icp about 20k ago, no oil in it. Fuel pump is good, got a new one in the truck but this is the second pump I've had on it in two days, same issue. Problem happens with stock tuning and stock hpop as well as with cales tunes and the srp1. I have a new ipr core from diesel site that I put on with the srp1 and the ipr solenoid ohmed out just fine, I put a known good one on from a wrecked truck we have, no change.

Batteries are new as of yesterday morning. I'm stumped...anyone have any ideas?

Video

[HaysKSFirefighter]

Bump.... .

[melmount]

Injctor O ings?
is the reservoir full when you try to start it? I assume it is but thats good to know.

[justinmix]

I would agree with injector o-rings. You really need a scan tool to moniter ICP pressures when it's doing this. What can happen is the upper o-ring on the injectors can start to eat away. When you're cranking it the high pressure oil will bleed out thru the o-ring and dump back thru the heads. It's probably a small leak at this time and it just takes awhile cranking for it to build ICP pressure. After it's running the high pressure oil system can overcome this leak for now. The reason it gets worse when warmed up is the oil thins out and pushes out even more.

It will probably get worse and worse though and might even blow out completely causing a no run issue.

Other possibilities would be a biased ICP sensor but I would think you would be having issues cold or warm with that.

Best thing to do is get someone to moniter ICP pressures and verify that's the problem.

[dazdillenger]

Do you have anyway to monitor ICP while cranking? Sounds like either injector o-rings, or a failing hpop.

[HaysKSFirefighter]

Originally Posted by melmount

Injctor O ings?
is the reservoir full when you try to start it? I assume it is but thats good to know.

Resi is about an inch from the top, just checked it when cold. This was from the sensor hole not the inspection hole, the plug was seized on.

Originally Posted by justinmix

I would agree with injector o-rings. You really need a scan tool to moniter ICP pressures when it's doing this. What can happen is the upper o-ring on the injectors can start to eat away. When you're cranking it the high pressure oil will bleed out thru the o-ring and dump back thru the heads. It's probably a small leak at this time and it just takes awhile cranking for it to build ICP pressure. After it's running the high pressure oil system can overcome this leak for now. The reason it gets worse when warmed up is the oil thins out and pushes out even more.

It will probably get worse and worse though and might even blow out completely causing a no run issue.

Other possibilities would be a biased ICP sensor but I would think you would be having issues cold or warm with that.

Best thing to do is get someone to moniter ICP pressures and verify that's the problem.

Ok, I'm getting it on a scanner on Friday, I'll take a video of ICP and IPR and put it on here.

Originally Posted by dazdillenger

Do you have anyway to monitor ICP while cranking? Sounds like either injector o-rings, or a failing hpop.

I will have access to a snapon scanner come Friday. I would bet orings since they have 260k+ on them. HPOP is a SRP1 with around 500 miles on it