Giving up on boost issue

[Daledammit]

I've searched forums and checked every suggestion I found. Car will only make 10lb boost. All stock engine. So far I have
Quadruple checked the Y fitting on the hoses to make sure it's right.
Replaced all vacuum lines with silicone hoses. Everything is zip tied.
Checked fuse to boost solenoid. Bypassed the boost solenoid with no change
Ran smoke machine test. It was leaking at the vacuum block gasket and egr valve. Replace both. Passes smoke test now.
Will hold 20" vacuum at start up and 14-16" after warm up.
Has a vdo boost gauge, I don't trust the dash boost gauge either.
No check engine lights and light does work. Put a bad Maf sensor on to make sure it would come on.
Still has stock wastegate. When I disconnect the hose to it, it will make 20lb boost under throttle.
I purchased the car a few months back. Only made 7lb originally. Had a break in the map sensor line next to the passenger fender, fixed it gained 3lb boost but no change since then.
Car has 53k miles, runs fine and accelerates fine, spools quick but only to 10lbs.
Wastegate moves freely when disconnected from actuator.
I don't think it's the turbo or the cat converter as it will make boost if you disconnect the wastegate. No slack or play in the turbine shaft.
New longer intercooler hoses. Good clamps. Smoke tested the intercooler, it passed also.
I haven't replaced the wastegate but my thoughts were if it will hold 20lb with the line unhooked the spring is ok but I might be wrong, I'm open to any input at this point. I do have a turbonetics (grainger) bleeder valve I connected inline to try as an adj wastegate but it didn't change anything either. Took it out just to eliminate it as a culprit.
I don't have a scan tool to connect for data but I feel like this has to be something simple I'm overlooking.
Stock chip in place, I want to get it boosting correctly before I make any changes to the car. Less mods less problems to rule out.
Car doesn't feel like it's holding back or losing power, I've had a few Buicks before so I do think the boost is accurate from seat of the pants feeling, just can't figure out where I'm losing boost or why it's being bled off early if that's the case.

Thanks for any advice, hints, tips, or thoughts.

 

[fastblackracing]

What mods does the engine have....Stock downpipe and elbow?

 

[Daledammit]

Yes stock down pipe, elbow, stock type exhaust, engine is completely stock to the best of my knowledge except for the just replaced egr valve, a remanned stock type mass air sensor, and a cone air filter.

 

[fastblackracing]

When you say bypassed the wastegate solenoid with no change what did you do?

 

[Daledammit]

I put the turbonetics bleeder valve in place between the compressor housing nipple and the wastegate per the diagram without the factory solenoid inline. I thought if the solenoid was bad it would boost correctly depending on the valve for control at that point. I didn't see any change up or down from 10lb Whether the valve was set wide open or closed. I took it off and reconnected the solenoid back like stock. The hose is on the solenoid port closest to the passenger fender and the other port isn't capped or plugged. It doesn't have that little foam filter on the uncapped side but I don't think that's necessary from what I've read.

 

[fastblackracing]

When you say bypassed the wastegate solenoid with no change what did you do?

I put the turbonetics bleeder valve in place between the compressor housing nipple and the wastegate per the diagram without the factory solenoid inline. I thought if the solenoid was bad it would boost correctly depending on the valve for control at that point. I didn't see any change up or down from 10lb Whether the valve was set wide open or closed. I took it off and reconnected the solenoid back like stock. The hose is on the solenoid port closest to the passenger fender and the other port isn't capped or plugged. It doesn't have that little foam filter on the uncapped side but I don't think that's necessary from what I've read.

Did you try running the turbonetics valve by itself between the compressor nipple and the waste gate?

It sounds like the waste gate solenoid is either not getting power pulses form the ecm or it is not able
to open the internal passage when the power is applied to it.

I would try the grainger valve by itself first, then take the solenoid valve off714
] apply power to it
while blowing thru it to see if it changes states. It does not matter what way the power is hooked up.

If the valve checks out good on the bench you need to reinstall it and find a way to monitor
if power is getting to the solenoid from the ecm....its not a straight 12 volt it is pulse width modulated
meaning the voltage is pulsed rapidly......but you will be able to see some kind of voltage an a meter
that will be less than 12 volts and maybe fluctuating. Or possibly attach a low wattage 12 volt light bulb
like a marker light or similar and it should be some what lit up.
This is driving down the road at full throttle.

The coil resistance should be around 20 ohms IIRC and the ecm will set a waste gate code only if
the resistance is gone, like is you disconnect it....It has no way of knowing if the solenoid valve
actually moves and changes states of the air passage.

 

[Daledammit]

I ran the grainger valve by itself without the factory solenoid at one point. I didn't see any change in boost levels with only it in line regardless whether it was screwed all the way in or out which I know can't be right. I'll try to test the factory solenoid like that tomorrow after work and see if it checks out okay. I didn't unplug the factory solenoid when I ran the grainger by itself. I'll try that too, but I would think if the vacuum line to it was disconnected it wouldn't receive any boost to bleed off

 

[Daledammit]

I also replaced the pcv valve and grommet before the smoke test. I really appreciate you taking the time to read this thread. I've been struggling with this for a month before I gave up and posted for help. But after weeks of searching old threads and finding a dozen things I hadn't checked and thinking great that's got be it with each one only to be let down every time, it's getting confusing and I can't figure it out. I'm sure it's something painfully obvious I'm missing and I'll probably deny it when I find it.

 

[bison]

Either exhaust can't get out, boost is leaking, or the wheels(s) are damaged and can't move the air to hit the boost you want. Maybe try a different gauge or get someone else's opinion. The solenoid can only further increase boost. It can't reduce is. Fixing a broken line to the map sensor will not get you 3psi at the manifold.


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[ITSAV6]

My car was making 10-11 psi when I bought it in 93. I installed a bleeder valve and was able to get over 20#, I eventually unhooked the vac line from wastegate solenoid and extended it into the interior with the bleeder valve between the seat and console. Could you post some pics?

 

[Daledammit]

I totally agree it shouldn't add 3psi fixing that single line but it was solid at 7psi before I fixed it and went to 10psi and has been since the first test drive afterward. Would the map sensor itself being basically disconnected create a running condition that would make that large a difference? The gauge in the car is a VDO that's less than 6 months old although if anybody could get a bad one it would be me. I have an Autometer gauge in my truck that is accurate to psi it's supposed to make. I'll try to pull it after work tonight and compare the numbers.

 

[Chuck Leeper]

Run a line directly from the turbo boost port to the w/g actuator. If it's a stock actuator, look for about 13#. If it's a hd actuator, look for 18#.
You said you unhooked the w/g sol and got 20#
Bison mentioned cat converter...You said "Will hold 20" vacuum at start up and 14-16" after warm up." 14" is too low for a stock engine.Could the 2 be associated? The original cat can be fried, and be an issue.. I'd take it off, hook everything back up, see what happens.
BTW, get a scan tool.

 

[Daledammit]

I haven't tried a direct line I'll do that, I know I need a scan tool but I let it go with my last car because I was done with buicks lol. Have a friend who has a direct scan in storage somewhere , moved from several buildings. trying to find it so I can buy it. I'll check the cat conv also. It's a stock wastegate. I was thinking 13lb too but I'm not seeing it and I feel like I'm losing boost somewhere because I can't get more than 10lb even with a bleeder valve. I have a new valve and an old one off a past car but I haven't tried it yet. I assume the new one works but you know how that goes.

 

[Pronto]

Might want to remove the elbow and see if the wastegate is actually sealing. The puck might be messed up.

 

[whitehot1]

I see you are from Alabama but not sure what part. Here is a thread from some N.Alabama members. Maybe you could reach out and contact them for some help.
If they are not in your area you could start a thread of your own. To let members know where in the state you need help. There could be someone right down the road from you. Another set of eyes can be a big help some times.

http://www.turbobuick.com/threads/n-alabama-tr-owners-sound-off.427493/

 

[Nick Micale]

................I don't think it's the turbo or the cat converter as it will make boost if you disconnect the wastegate. No slack or play in the turbine shaft.

Thanks for any advice, hints, tips, or thoughts.

My thought would be to first check the 30 year-old cat?

I have seen many old cats break up and the car will run, but not real power.

Just remove the 2 long bolts at the downpipe to bypass the exhaust.

 

[Turbo Keith]

My car was making 10-11 psi when I bought it in 93. I installed a bleeder valve and was able to get over 20#, I eventually unhooked the vac line from wastegate solenoid and extended it into the interior with the bleeder valve between the seat and console. Could you post some pics?

I would like to see those pics , Thanks Keith

 

[Daledammit]

Ok thanks for the input, I'm at work but I can post a pic of hose and Y connector when I get home tonight. I can check the cat too. I didn't know there was a north Alabama thread, that will come in handy. Looks like most of the guys are less than two hours away from me. I'm about 45 miles from Birmingham.

 

[Daledammit]

Ok this evening pulled the cat converter, it's been gutted but I put a test pipe in place anyway since it was off. No changes noted in boost, still at 10lbs

Ran a line straight from the compressor nipple to the wastegate. Car idled a little rougher for whatever reason but smoothed out under light throttle. Boost dropped to 9lbs.

I just now cut the zip ties off but my hoses were run with straight part of the Y going to compressor nipple and the solenoid with angle part connected to the wastegate. I know it looks backwards from that in the picture but the Y connector rolled over when I put the straight hose from the compr. nipple to the wastegate.

I'm going out to swap the gauge now for the one in my truck to compare numbers.

I will try to run my old grainger valve inline by itself and see if the new one is jacked up also. It's completely disconnected from the system at this point though just have ruled it out.
I've actually never had a stock wastegate I'm assuming it will work with a grainger valve and I don't have to have an adjustable one just to increase a few pounds over stock.

I have not pulled the elbow to make sure the puck is seating but I feel like if I pull the wastegate line off altogether and it spikes the boost it must be sealing. I'm willing to pull it if necessary though.

 

[Daledammit]

View attachment 284869 Ok this evening pulled the cat converter, it's been gutted but I put a test pipe in place anyway since it was off. No changes noted in boost, still at 10lbs

Ran a line straight from the compressor nipple to the wastegate. Car idled a little rougher for whatever reason but smoothed out under light throttle. Boost dropped to 9lbs.

I just now cut the zip ties off but my hoses were run with straight part of the Y going to compressor nipple and the solenoid with angle part connected to the wastegate. I know it looks backwards from that in the picture but the Y connector rolled over when I put the straight hose from the compr. nipple to the wastegate.

I'm going out to swap the gauge now for the one in my truck to compare numbers.

I will try to run my old grainger valve inline by itself and see if the new one is jacked up also. It's completely disconnected from the system at this point though just have ruled it out.
I've actually never had a stock wastegate I'm assuming it will work with a grainger valve and I don't have to have an adjustable one just to increase a few pounds over stock.

I have not pulled the elbow to make sure the puck is seating but I feel like if I pull the wastegate line off altogether and it spikes the boost it must be sealing. I'm willing to pull it if necessary though.