Engine/Transmission (1994 - 1998) pressure test of the intake system

[JRS]

How do I pressure test the intercooler and it's hoses for leaks? (I am down on boost about 4-5 psi) I have checked the overflow valve, no problems there. Will also check the fuel filter tonight, in addition to the intercooler and lines.

 

[RT66DOC]

JRS

Check the article in TDR Issue #43, p. 44, 45, 46 - "Low Turbocharger Boost" by Jim Anderson. All you need to know. Even shows you how to make the tool you need to pressure test the system for very few bucks.



HTH

 

[JRS]

thanks. I'll look around for it. Afraid it's been thrown out.

 

[RT66DOC]

Thrown out??? This is not Newsweek we're talking about here, JRS. This is reference and research material. I have every issue back to #1 - much to my wife's consternation.



Seriously, the general idea of making the pressure tester was to pick up a 4" rubber plumbing pipe cap - Fernco - from Lowe's or Home Depot. Then drill a hole through the center of it so you can stick a tire valve thru it. Cement it in with one of those "Camel" tire patch things then let it sit over night. Then secure it over the intake with a band clamp and apply some air pressure. If you can't find your TDR let me know and I'll get all the specifics about how much pressure and what to look/listen for, etc.

 

[JRS]

ok, ok, I found the issue. So far I have removed/cleaned then re-installed and pressure checked all the rubber boots. no leaks or cracks or wear spots. Removed the boost pipe and checked it. no leaks in it or it's hoses. replaced the fuel filter, even though the other one looked fairly new and only had several thousand miles on it. replaced the air filter. Checked the overflow valve and stretched the spring ever so slightly back to normal. (Valve only has 20,000 miles on it. New valve from Piers should arrive early next week. ) Checked the tubing to my boost gauge too, still nice and tight on the barb. Boost is now up to 26 psi, maybe 27psi from 24-25 psi. truck seems to have more pull, but that's empty and not pulling a trailer. Towing again on Friday. If I can't get 30 psi of boost fully loaded, even with the new overflow valve, I'm at a loss of what to do next.



I finally figured out the time period of when this happened. About a month ago, I lost the 5th gear nut towing my trailer to a race. I drove at least six hours at about 2850 rpms in 4th gear to get to the race. But, I just don't see how this would be connected

 

[RT66DOC]

OK, now this is over my head. Maybe one of the more savvy boostmeisters will chime in here.



Glad you found your TDR.

 

[LJHagen]

Originally posted by RT66DOC

Thrown out??? This is not Newsweek we're talking about here, JRS. This is reference and research material. I have every issue back to #1 - much to my wife's consternation.



Seriously, the general idea of making the pressure tester was to pick up a 4" rubber plumbing pipe cap - Fernco - from Lowe's or Home Depot. Then drill a hole through the center of it so you can stick a tire valve thru it. Cement it in with one of those "Camel" tire patch things then let it sit over night. Then secure it over the intake with a band clamp and apply some air pressure. If you can't find your TDR let me know and I'll get all the specifics about how much pressure and what to look/listen for, etc.

I'm looking at doing the same thing (30 psi max with a #12 and the wastegate blocked off)... When you put the cap on the intake, is that between the air filter and turbo or turbo and intercooler? Also, do you have to do anything over at the intake side so you don't just blow air down any open valves in the head?

 

[Forrest]

Originally posted by JRS

How do I pressure test the intercooler and it's hoses for leaks? (I am down on boost about 4-5 psi) I have checked the overflow valve, no problems there. Will also check the fuel filter tonight, in addition to the intercooler and lines.

Is smoke up?

 

[JRS]

it appears to have some more smoke, but nothing major. Will be towing my trailer tomorrow. than will be the real test.

 

[Forrest]

That's good. If it had the same amount of smoke, then perhaps it's putting our less fuel, therefore less boost.

 

[JRS]

I have noticed that I have no trouble building boost pressure up to 26-27 psi. the needle swings up right away. it's that last 3-4 psi that I'm lacking.

 

[Forrest]

This is a long shot, but does your turbo have the wastegate signal port on the compressor housing? The threaded plug fell out of mine ... had the same symptoms.

 

[JRS]

thanks. I'll check.

 

[gitchesum]

You might also check the adjustment on the boost elbow. Mine had worked it's way out and was also having low boost problems. It's just a set screw threaded into the elbow. I used a little loc-tite when I put it back together.

 

[JRS]

Ok, my boost elbow is leaking. there is air coming out the hole drilled into the side. (about 8psi on the system) Also coming out of the threads around the allen head. how far do I thread this back in once I take it out and loc-tite it?

 

[mkhenry]

Where is the boost elbow and is it adjustable on a 1994 truck

 

[JRS]

it's the brass elbow that TST supplied with my #11 plate. it has an allen head screw in it to adjust the boost and a weep hole. the allen head screw is leaking.

 

[gitchesum]

I would just turn it in a little and test drive it. Take the allen wrench with you so you can pull in anywhere and adjust it on the spot. Just adjust it to anywhere between 32-34 psi. You should be fine there.

 

[JRS]

what's best to seal the threads with? silincone? loc-tite? (blue)

 

[gitchesum]

I used what ever I had in the tool box, red I think. Probably didn't need that much holding power though.



Same stuff I used on my 5th gear nut.