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86lance
10-08-2006, 03:43 PM
Since ive been having some problems with boost creep I was wondering if i could put some sort of bleeder valve in place of the restrictor after my boost controller. I just dont think the restrictor i have is bleeding off enough pressure causing my boost to creep to cutout.
86lance
10-08-2006, 06:30 PM
dumdedumdum. I tried switching the boost controller pressure source from the turbo compressor outlet and rehooking it up to the intake manifold and it didnt help. What are the chances that im blowing boost pressure thru my pcv valve?
86lance
10-09-2006, 01:02 AM
hmmm noone?
Whorse
10-09-2006, 02:33 AM
Not a sticking wastegate?
86lance
10-09-2006, 08:17 AM
i duno how the hell id unstick it if it was,lol. If its stuck itr isnt tyhat b ad cuz the creep is pretty slow.
MiniMopar
10-09-2006, 11:13 AM
What turbo is this? Could be a leaky wastegate actuator diaphram (or vacuum line). You can test that pretty easily by pumping it up with some pressure and seeing if it bleeds off.
86lance
10-09-2006, 01:18 PM
It is an 89 garret t2. Stock everything except for intercoolers(dual TD's) Nothing leaks AFAIK. Ive checked everything a bunch of times now. All vacuum lines are good and brand new. A leaky wastegate actuator will cause creep? I thought that would cause weak boost?
MiniMopar
10-09-2006, 01:53 PM
Pressure pushes it open, the spring pulls it closed. If it can't build pressure in the can, then it can't open the WG.
86lance
10-09-2006, 04:44 PM
ghaa this is confusing. Say i have my g-valve set for 12 psi ok. When my g- valve opens at 12 psi it pushed the arm on the wastegate actuator out. When it does that it opens the wastegate hole to maintain 12 psi? So if im getting this correctly it goes like this. The wastegate actuator may or may not have a leak in it. When boost pressure opens it up it starts to leak and the exhaust gases slowly close the flapper on the wastegate hole causing creep? If so that sounds like it might be my problem. Symptoms wise that is. Thanks!
MiniMopar
10-09-2006, 05:01 PM
Yeah, it's just an idea. The Garretts don't typically have much trouble with creep, so it makes me think that there is something up with the WG. I'd put a check valve on the WG actuator and pump it up with a bicycle pump or something (compressor set to 20psi if you have one) and watch the arm. It should come out and stay out. If it keeps going back in, it is leaking. If not, then it is probably OK and your exhaust just outflows the turbo so much that the wastegate port can't dump enough exhaust. The solution then is to defeat the OB cutout and add more fuel. :D
BadAssPerformance
10-09-2006, 05:35 PM
Simple finger pressure test on the actuator.

Remove the vacuum line
Pull the actuator rod to open the wastegate
cover vacuum inlet with finger and hold tightly
let go of actuator rod
look at and listen to actuator while removing finger to see if it moves
repeat a couple times to know for sure

If your finger holds pressure actuatore is good if not it probably is not.

This is a quick easy test but Russ' pump test is a better way if this test is indecisive for you.
MiniMopar
10-09-2006, 05:37 PM
Good call...much simpler. Sometimes I just do things the hard way...LOL.
86lance
10-09-2006, 10:34 PM
SWEET! Great to to test it! I hadnt thought of that before at all,lol

Ill have to do that in the morning. But if the actuator checks out fine then bammo more fuel and more boost,lol