Engine/Transmission (1998.5 - 2002) Boost Adjust lengthen/shorten Waste Gate Rod?

[Joe Mc]

To increase boost psi do you lengthen the WG rod or shorten it?



Been a while since I turned it down and need to bump back up.

 

[Joe Mc]

OK just found a site explaining - shorter rod = more boost and longer means less.

So when I first got the HTT - QD 64/14 (about 3 years ago) I could max the 50# gage so I adjusted down so as not to pop the head gasket to about 45. Now I just noticed the gage was only maxing at 38 maybe 40, truck isn't hitting the gears as hard and it seems a bit low on performance when getting on it in the upper rpms. Tonight I shortened the rod until it became difficult to turn the nut (I can still see about 4 rows of threads) and there's no change in boost = still 38 - 40.

Is there something holding it back - electronics de-fueling it somehow or is the gate leaking a possibility?

All ideas welcome - no CEL, haven't check for codes will do in the AM and report back.

 

[DCreed]

pull the cover on the gates and look for signs of cracking or bent hardware causing the pucks to not seal. You also should do a pressure leak test on the whole system.

 

[Joe Mc]

Sorry, not sure what you mean "cover on the gates" and "pucks". I'm thinking there's something "cover" that can be removed to inspect the "pucks" (sealing mechanism" that closes off vent/gate. As for psi of system, new silicon hoses installed and inspected inter-cooler while tabbing dowel (had radiator out BC no big wrench to get fan off of pulley and was able to visual both sides of IC).

I checked all hoses and not one has budged = all were installed with no kinks or otherwise faulty installation. Old hoses were still good just 10 years + 180k old = boost was low prior to tabbing and new boots.

I'm wondering if there's a dirty electronic sensor, MAP, IAT, or ? that would cause this?

Back when first installed I had a 0 - 30 gage that wasn't reading anything, guess I blew the gage first time I romped on it, anyway performance seem excellent but it was suggested to clamp WG hose to see if there was any difference. Which I did for a mild run and since no diff I took clamp off hose. I guess I could try that again, but if there's an internal leak in the WG this wouldn't prove anything - Yes?

 

[DCreed]

if you are using a mech gauge for boost then dirty sensors wont change the reading. You can clean the IAT and MAP sensors. they are on the drivers side rear of the engine under the manifold plate (just follow the wires). a pressure test is simple and would eliminate any "may be's" in the CAC system.
There have been issues with some S300s bending the bridges that hold the pucks and also exhaust housings cracking in the gate area. Prolly easiest to pull the turbo and inspect on a bench with good light as they can be hard to spot when all sooty and still in the truck.

 

[Joe Mc]

Kinda figured it involved R & R of turbo. Looks like that'll be this weekend's project.



Thanks

 

[Joe Mc]

I'm assuming after I remove and inspect I'll need some parts. Anyone have a parts list/breakdown for my HTT, Series 71 Quick Diesel 64/14 and a source for parts?