find boost leak

[05lly2500hd]

Well I spoke with an autometer tech and he verified that the boost sensor would work for fuel.
So the 4psi is an accurate reading I'm getting. I'm thinking of upgrading to an airdog/mitusa/PPE, just goota make up my mind. I hear more and more of these pumps Kennedy/TTS failing.

Bought a new intercooler from GM, the parts guy even delivered it to me after he got off work, talk about service!
Now to find the time to install and I'll let you guys know how it turns out. Thanks for the help and suggestions.

on edit: I just remembered the gauge was going wacko, so I checked under the hood and the harness was melting to the twin exhuast and I noticed a leak on the metric-SAE threads. So I'll fix that, and replace my WIF before I buy a new pump setup.

 

[05lly2500hd]

I'm not exactly sure where I left off here, but I'm back tackling this again.
Between being laid off and moving, misplacing my EFILive cord, phone and laptop crapping on me..................I could go on, LOL.

So i replaced the intercooler which was a PITA, I haven't been able to get ahold of Nathan for the o-ring on turbo. All local parts stores and Harbor Freight carry nothing even close to this size. I believe I'm building 38 lbs of boost, so I'm hoping the o-ring will fix the boost problem.

What do I look for if I pull the fuel sending unit? I have a 5/8" rubber hose and Trippin pickup. Do I just look for anything out of place or a kinked hose? I remember sometime a LONG time ago about exact measurements of in tank hose being sent out because guys were making them too long. If so what was this measurement? I'd like to have a hose on hand in case this is a prob.
Again, I got weird readings on the autometer gauge for fuel pressure, with either ONE of them unhooked(just one). Maybe their both on their way out.
Airdog II seems nice, but I'm no employed.
So, I'm gonna work on getting the o-ring and possibly pulling the bed off and opening the tank. Then I'll go to replacing lift pumps.
How many guys are running the PPE lift pump vs. the Airdog II?

 

[paint94979]

I'm not exactly sure where I left off here, but I'm back tackling this again.
Between being laid off and moving, misplacing my EFILive cord, phone and laptop crapping on me..................I could go on, LOL.

So i replaced the intercooler which was a PITA, I haven't been able to get ahold of Nathan for the o-ring on turbo. All local parts stores and Harbor Freight carry nothing even close to this size. I believe I'm building 38 lbs of boost, so I'm hoping the o-ring will fix the boost problem.

What do I look for if I pull the fuel sending unit? I have a 5/8" rubber hose and Trippin pickup. Do I just look for anything out of place or a kinked hose? I remember sometime a LONG time ago about exact measurements of in tank hose being sent out because guys were making them too long. If so what was this measurement? I'd like to have a hose on hand in case this is a prob.
Again, I got weird readings on the autometer gauge for fuel pressure, with either ONE of them unhooked(just one). Maybe their both on their way out.
Airdog II seems nice, but I'm no employed.
So, I'm gonna work on getting the o-ring and possibly pulling the bed off and opening the tank. Then I'll go to replacing lift pumps.
How many guys are running the PPE lift pump vs. the Airdog II?

i really like my PPE lift pump... 2 1/2 years it works flawless. Are you sure you have found all of the boost leaks? remind me again how you tested for the leaks?

 

[05lly2500hd]

i really like my PPE lift pump... 2 1/2 years it works flawless. Are you sure you have found all of the boost leaks? remind me again how you tested for the leaks?

I used a small compressor, and pressure checked it, there was a tiny hole in the intercooler, so I replaced intercooler. At the same time I installed a Banks CAC pipe and new boots on both ends. I've checked each turbo for movement, all well.
I do not have an o-ring where the intake elbow meets the stocker turbo, which a member stated the loss of his made a significant boost leak.

The only thing air did not enter while doing the test is the second turbo.



What is the biggest advantage of the Airidog II over the PPE? the air/water filtration?

 

[paint94979]

I used a small compressor, and pressure checked it, there was a tiny hole in the intercooler, so I replaced intercooler. At the same time I installed a Banks CAC pipe and new boots on both ends. I've checked each turbo for movement, all well.
I do not have an o-ring where the intake elbow meets the stocker turbo, which a member stated the loss of his made a significant boost leak.

The only thing air did not enter while doing the test is the second turbo.



What is the biggest advantage of the Airidog II over the PPE? the air/water filtration?
I'm only building 20k where 25k is demanded fuel pressure.

Do what I did, tap into your intake manifold using an 1/8 tap, find a fitting with 2 male 1/8 connections on it, then you can screw your air compressor nozzle right into the truck. I don't remember what the size of the intake inlet is on the small turbo but go to Home Depot and buy a rubber pipe cap (3inch, or 3.5inch) and cap off your turbo. Test up to 30psi+ i guarantee you will have a big boost leak somewhere.

 

[05lly2500hd]

Do what I did, tap into your intake manifold using an 1/8 tap, find a fitting with 2 male 1/8 connections on it, then you can screw your air compressor nozzle right into the truck. I don't remember what the size of the intake inlet is on the small turbo but go to Home Depot and buy a rubber pipe cap (3inch, or 3.5inch) and cap off your turbo. Test up to 30psi+ i guarantee you will have a big boost leak somewhere.

I don't understand. Cap off smaller turbo and tap intake will this not only push air to the bigger turbo?

 

[paint94979]

I don't understand. Cap off smaller turbo and tap intake will this not only push air to the bigger turbo?

you can cap off the big turbo... i would just make it simple, cap the small turbo then if there are NO leaks then reconnect the tube that connects the big turbo to the small turbo, cap the big turbo and go from there. I might not be able to picture this missing Oring but i can't see how that would cause the problem but a pressure test will show it if it is. Does your boost HOLD at 38psi the whole time? I had a big leak and boost bleed off quick

 

[05lly2500hd]

you can cap off the big turbo... i would just make it simple, cap the small turbo then if there are NO leaks then reconnect the tube that connects the big turbo to the small turbo, cap the big turbo and go from there. I might not be able to picture this missing Oring but i can't see how that would cause the problem but a pressure test will show it if it is. Does your boost HOLD at 38psi the whole time? I had a big leak and boost bleed off quick

38psi is a spike, peak.

 

[paint94979]

38psi is a spike, peak.

so describe what your boost does.... 10.. 16...28... then 38

 

[05lly2500hd]

so describe what your boost does.... 10.. 16...28... Then 38

10..15..20..25..30..30..30..30.35.30..30 :d

 

[LarryJewell]

Let me throw something else in the mix that I believe is fuel related....it turns over a bit more than normal before it cranks, and by playing with cranking inj. qty. it gets better

I wonder if air in the system would cause this as well? maybe that's why I have that damned annoying burp idle.


on edit: just went to truck....gauge is definately working, whether it's accurate or not I don't know. But with truck on but not cranked it's showing 2.5 psi, drops to 0psi while cranking and goes up to 4psi while idling.

Fuel pressure related, single cp3 add a little pressure, duel cp3 reduce a little pressure in the base table (in the 600-800 rpm range).

 

[05lly2500hd]

Fuel pressure related, single cp3 add a little pressure, duel cp3 reduce a little pressure in the base table (in the 600-800 rpm range).

how much is a little to start at? (single cp3)

 

[LarryJewell]

how much is a little to start at? (single cp3)

Change the cells from 600-800 rpms and down to 35mm3 to (35), they are probably (30) right now.

 

[05lly2500hd]

Change the cells from 600-800 rpms and down to 35mm3 to (35), they are probably (30) right now.

ill give it a shot thanks.

 

[05lly2500hd]

well i think i got the boost fixed, it was either the intercooler, driver's side CAC pipe or the turbo o-ring, OR the fact that my damned autometer boost gauge and sensor are inaccurate.

 

[JoshH]

Jeromy, after reading all your fuel pressure related problems, I think you either have a high fuel leak on the high pressure side (would probably be an FPRV seeping fuel) or an injector with a very high return rate. Have you done a bottle test?

 

[05lly2500hd]

Jeromy, after reading all your fuel pressure related problems, I think you either have a high fuel leak on the high pressure side (would probably be an FPRV seeping fuel) or an injector with a very high return rate. Have you done a bottle test?

yes did a bottle test, no fuel in bottle.

 

[JoshH]

yes did a bottle test, no fuel in bottle.

What about signs of fuel leaks under your hood? Any smell of diesel or wetness around line connections? If not, I bet you have an injector that is returning a lot of fuel and bleeding off pressure.

 

[05lly2500hd]

What about signs of fuel leaks under your hood? Any smell of diesel or wetness around line connections? If not, I bet you have an injector that is returning a lot of fuel and bleeding off pressure.

man I have looked all over this truck for both boost and fuel leaks, to no avail.

 

[JoshH]

I seem to remember reading something about how to do an injector return rate test a while ago, but I don't remember how it is done. I would suggest you check into that though.