Testing the STC fitting

[01REDSTROKER]

Can you test the STC fitting using AE?
Have a 2006 6.0 warm or cold start it takes twice as long to start as it should.
no codes
GP's check fine with AE

 

[POWER-STRUCK]

command the ipr closed and apply air pressure, listen for leaks

 

[01REDSTROKER]

someone told me that you could command the ipr closed with the truck running and listen for a knocking noise. said it was better so u didnt have to purge the system of air?

wanted to ask you guys before i did it.

 

[Mdub707]

The real way to air test is to apply an outside 12V source to the IPR to fully close it (to my knowledge it cannot be fully commanded closed via software) then air test the system and listen for leaks.

An STC failing usually causes hard warm starts. If you're having problems starting cold or warm, I'd look elsewhere personally.

If you have AE, what are your readings for ICP actual, ICP desired and IPR %? What's your battery voltage? FICM voltage?

 

[01REDSTROKER]

FICM voltage is good 48-49 koeo, starting and runinng
battery's are good.
have not looked at the icp numbers or ipr %

The real way to air test is to apply an outside 12V source to the IPR to fully close it (to my knowledge it cannot be fully commanded closed via software) then air test the system and listen for leaks.

An STC failing usually causes hard warm starts. If you're having problems starting cold or warm, I'd look elsewhere personally.

If you have AE, what are your readings for ICP actual, ICP desired and IPR %? What's your battery voltage? FICM voltage?

 

[Mdub707]

Check those out and see what you're getting when it's cranking.

 

[thirdgenlxi]

The problem with doing the air test with the later models or those that have the newer standpipes, is you apply the air to the right (passenger) side oil rail through the ICP hole, but then the standpipes have check valves that keep the air isolated to that oil rail, and it never makes it back to the STC or the LH oil rail. I've had leaks from STC fittings and never been able to hear a thing, more or less just had to take the valve covers off first and inspect the dummy plug o-rings, and if they were OK then go back to the STC fitting. Unless of course you have one of the old style standpipes without the check valve to throw in there to test with. More times than not it's the dummy plugs, but still very well could be the STC as well

 

[01REDSTROKER]

Thank you for the information. I will be able to look at the truck later this week and will report the findings.

 

[01REDSTROKER]

Ok guys truck died on my brother this morning.
Using AE
Icp 36 psi
Icp desired 1250 psi
Icpr % 84.89

Lpo gauge in the dash does not move while cranking. But removed oil filter and held down the drain and filter spring and it filled with oil.

 

[thirdgenlxi]

Definitely sounds like either the fitting or it blew a hole in the IPR screen..... either will cause low ICP. The o-rings on the oil rail plugs usually isn't enough to make it stall, just hart/no start hot. If you pull the IPR valve out and it looks good, it's likely the STC fitting (though just cuz the IPR 'looks' OK doesn't always necessarily mean it is, but more times than not it'll have a hole in the screen if that's the culprit)

 

[Mdub707]

IPR might be stuck, or your HPOP is shot...

The gauge on the dash takes a few seconds to come up. I think when I was having a no start issue it took a full 6 seconds for my low pressure gauge to come up.

 

[01REDSTROKER]

Is there any way to prove it is the ipr or hpop ?
Going to replace the stc fitting since it will break sometime if it already hasn't.
Thanks.

 

[Mdub707]

The IPR you should be able to pull and just visually inspect, it's just a valve. If it's shoved full of metal shavings, it's likely the HPOP. I would start with the IPR though, if it's stuck it wont let the HPOP build the proper pressure I'd imagine. However, that ICP reading is REALLY low... as in dead HPOP low.

When you're cranking, does IPR start off at 85%, or does it start low and gradually build up to that?

 

[01REDSTROKER]

The ipr starts low and ramps up to 84% in just a few seconds.

 

[Lassie]

I got money its the STC fitting...Dummy plugs with blown orings will still usually allow 250 - 350 psi to build. The STC fitting has probably seperated and you simply cannot build any pressure at the sensor in the rail. I don't think an IPR could relieve pressure fast enough to only reach 30 psi if it wanted to.

Also, to air test, the external IPR power supply is not needed for testing with shop air. Turn the key to your truck to "on" and the IPR will be commanded to 15% duty cycle. The IPR is a regulator, not a gate valve, so you are not opening and closing with your signal, you are setting a relief pressure. 15% DC is more than enough to build a few hundred pounds of pressure in the system. This is plenty to easily find dummy plug leaks, STC fittings, or injector orings. And you don't risk damaging the IPR with full signal for too long. Now, some problems require higher pressures....like split HPO rails....and you will need some way to command the IPR to hold much higher pressures. But for that, you would be using 1000 psi or so nitrogen. So, if you're only using shop air, KOEO will hold fine.

 

[Mdub707]

I got money its the STC fitting...Dummy plugs with blown orings will still usually allow 250 - 350 psi to build. The STC fitting has probably seperated and you simply cannot build any pressure at the sensor in the rail. I don't think an IPR could relieve pressure fast enough to only reach 30 psi if it wanted to.

Also, to air test, the external IPR power supply is not needed for testing with shop air. Turn the key to your truck to "on" and the IPR will be commanded to 15% duty cycle. The IPR is a regulator, not a gate valve, so you are not opening and closing with your signal, you are setting a relief pressure. 15% DC is more than enough to build a few hundred pounds of pressure in the system. This is plenty to easily find dummy plug leaks, STC fittings, or injector orings. And you don't risk damaging the IPR with full signal for too long. Now, some problems require higher pressures....like split HPO rails....and you will need some way to command the IPR to hold much higher pressures. But for that, you would be using 1000 psi or so nitrogen. So, if you're only using shop air, KOEO will hold fine.

Good info.

One thing that still doesn't make sense to me... he loads a different tune on and it fires right up... if the STC was indeed split... I can't imagine it starting on any tune... opcorn:

 

[Lassie]

Good info.

One thing that still doesn't make sense to me... he loads a different tune on and it fires right up... if the STC was indeed split... I can't imagine it starting on any tune... opcorn:

I think you might be crossing threads here....or I'm just blind or can't read!

 

[PowerStrokeEnginuities]

replace stc fitting, rail plgs and stand pipes. check ipr screen, if it has a hole in it, repalced ipr. if it doesnt replace screen with kit that comes with stc fitting. fix it right the first time, unless you want to keep chasing leaks later.

 

[Lassie]

If you isolate to the STC fitting, there is no need to go into valve covers. All of your work will be under the turbo.

I guarantee that you will be back under the oil rails soon enough......owning a 6.0 and all.....and you can upgrade those plugs and pipes then. The STC is the leak source that will leave you stranded.

 

[Mdub707]

I think you might be crossing threads here....or I'm just blind or can't read!

Holy crap, I need to walk away from the computer for a little while LOL


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