Will weak/bad HPOP cause...

David N · Oct 11, 2015

A no start issue only when hot?

Its my truck in my signature. Just got my injectors back from Full Force, which are now 350/200's. It still won't start when hot. Starts up perfectly when cold other than a romp/choppy idle for a few seconds, then clears up.

It has new IPR and ICP sensors, new Mobil 1 5w-40 oil, and the reservoir is always full when the no start issue happens.

According to my AutoEngenuity, cranking while hot, ICP is anywhere from 250-350psi. While duty cycle slowly climbs all the way to 90-95%.

I have no idea on HPOP age, as it was on the truck when I bought it. I do know with my injectors that my ICP drops to 1500psi during WOT runs.

Any ideas?

Vader's Fury · Oct 11, 2015

Yes it can. Sounds like somewhere you have a leak and once the oil thins out it leaks faster than the pump can make pressure.

I would isolate and pressurize each head just to rule them out for a leak then change the pump.

David N · Oct 11, 2015

Vader's Fury said:
Yes it can. Sounds like somewhere you have a leak and once the oil thins out it leaks faster than the pump can make pressure.

I would isolate and pressurize each head just to rule them out for a leak then change the pump.

Yeah its leaking somewhere. What else could be leaking in the heads? Injector orings are new, and it has same symptoms as before I took them out, so I believe there aren't any cut.

Vader's Fury · Oct 11, 2015

Are you losing oil? Level stay consistent?

David N · Oct 11, 2015

It will burn a little bit between 5k mile oil changes, but no significant amount.

Arisley · Oct 11, 2015

How did the o-rings look on the injectors you pulled out?

You did slobber up the new injectors with oil on install, correct?

mandkole · Oct 11, 2015

Vader's Fury said:
Yes it can. Sounds like somewhere you have a leak and once the oil thins out it leaks faster than the pump can make pressure.

I would isolate and pressurize each head just to rule them out for a leak then change the pump.

Agree. you could also cap and gauge the pump. The leak is in the pump or the head (s)

David N · Oct 11, 2015

Arisley said:
How did the o-rings look on the injectors you pulled out?

You did slobber up the new injectors with oil on install, correct?

They were perfect. And yuppppppp. Oiled them up good-fashioned.

lincolnlocker · Oct 11, 2015

David N said:
They were perfect. And yuppppppp. Oiled them up good-fashioned.

i use a gallon oil jug. cut the top off. perfect size to fit all 8 injectors. put injectors in and fill full of oil. works well if you leave the handle on too.. lol

live life full throttle

OBS-Addiction97 · Oct 12, 2015

Check the Oil galley plugs.

David N · Oct 18, 2015

Well I made a setup out of a grease gun to test each head.

Pumped them up to 3000 psi (which was kinda hard to get to) and shut it off. It took 55 seconds to leak down from 2700psi to 1000psi. Then another minute to leak from 1000psi to ~400psi. Which is ironically around all the ICP the truck will build when its hot and wont start.

Does this sound normal? Also, there is a small amount of oil coming from the weep holes on the back of at least 3 of the 4 injectors on the passenger side. I can't see the very back injector. I'd say each is dripping a drop every 2 seconds or so.

mandkole · Oct 18, 2015

David N said:
Well I made a setup out of a grease gun to test each head.

Pumped them up to 3000 psi (which was kinda hard to get to) and shut it off. It took 55 seconds to leak down from 2700psi to 1000psi. Then another minute to leak from 1000psi to ~400psi. Which is ironically around all the ICP the truck will build when its hot and wont start.

Does this sound normal? Also, there is a small amount of oil coming from the weep holes on the back of at least 3 of the 4 injectors on the passenger side. I can't see the very back injector. I'd say each is dripping a drop every 2 seconds or so.

No, not normal-- it should be much more sealed than that and no oil dripping. The poppets are leaking and that is likely where pressure is bleeding, but could have an oring issue also.

thuglike · Oct 18, 2015

A hot no start or idle issue is almost always an injector(s)
mandkole is spot on I believe!!

lincolnlocker · Oct 18, 2015

thuglike@dynoproven said:
A hot no start or idle issue is almost always an injector(s)
mandkole is spot on I believe!!

unless you have a srp pump....

live life full throttle

David N · Oct 18, 2015

I just got these injectors back from full force after getting the go ahead. They might have 20 miles. And I'm certain Orings are good to go. It's doing the same mess it was before I pulled them, and all orings were good then.

What's the next step?

lincolnlocker · Oct 18, 2015

David N said:
I just got these injectors back from full force after getting the go ahead. They might have 20 miles. And I'm certain Orings are good to go. It's doing the same mess it was before I pulled them, and all orings were good then.

What's the next step?

did you isolate each head from the hpop? i assume you plumbed into the port where the hpop line goes to each head. or did you pull a oil rail plug and plumb into it there?

live life full throttle

psduser1 · Oct 18, 2015

lincolnlocker said:
unless you have a srp pump....

live life full throttle

Shut yur piehole.....

lincolnlocker · Oct 18, 2015

psduser1 said:
Shut yur piehole.....

you will see one day

live life full throttle

David N · Oct 18, 2015

lincolnlocker said:
did you isolate each head from the hpop? i assume you plumbed into the port where the hpop line goes to each head. or did you pull a oil rail plug and plumb into it there?

live life full throttle

Yep I took the line off and plumbed straight into the head that way. Only oil passing I could see passing anywhere were out of the weep holes.

lincolnlocker · Oct 18, 2015

David N said:
Yep I took the line off and plumbed straight into the head that way. Only oil passing I could see passing anywhere were out of the weep holes.

with tested injectors that you just had sent in?

live life full throttle