14B Turbo Boost question

[extremedsm91]

I am having a problem and it is pissing me off!!!!! 92 laser awd with manual trans. Mods, no exhaust after down pipe, o2 dump and boost controller. I can only get 8 pounds of boost. Tried one wastegate acc, and put a new one on, 2 bov's, wired the wastegate shut, took bov out and put a straight pipe in there and have the boost controller maxed. Only 8pds. Just ported turbine housing, the flapper is seating and everything is in good shape. Turbo spins great, VERY LITTLE shaft play and no smoke at all. Did boost leak test and there is a VERY SMALL amount coming out of the throttle plate shaft and that is it. It seems to spool slow and only up to 8 pounds. Any help?????????????

 

[oldman]

Seems like you have everything covered. Check for exhaust leak before O2 housing, if that checks out, the only thing left would be the turbo itself.

 

[extremedsm91]

When I put the turbo in, the turbine housing looked very good. I think the turbo is the only thing left but it seems to be fine. Spins great, very little shaft play and all the fins are still there. Can there be something else wrong with it?

 

[oldman]

Let's go through what you have done so far.

wired the wastegate shut, took bov out and put a straight pipe in there and have the boost controller maxed.

Please explain.

Did boost leak test and there is a VERY SMALL amount coming out of the throttle plate shaft and that is it.

At this point, how much pressure was the system holding and for how long?

Which turbo, bov and mbc?

 

[Maestr0]

Problem I had is the bushing holding the wastegate slid out, pulling it over and uncovering the wastegate hole. Made spoolup and slow and boost low

 

[extremedsm91]

Checked that, it is fine.

 

[extremedsm91]

New 14b on, 8psi...............................................

 

[project_tsi]

Is the MBC hooked up correctly?

You didn't forget to unhook the stock BCS did you?

Or, Maybe the MBC is adjusted wrong, too far out, or in, and it's not in its "sweet spot", for adjustments?

 

[oldman]

If you're looking for serious help, answer all the questions in detail.

 

[extremedsm91]

Is the MBC hooked up correctly?

You didn't forget to unhook the stock BCS did you?

Or, Maybe the MBC is adjusted wrong, too far out, or in, and it's not in its "sweet spot", for adjustments?

I took the mbc out of the picture when I wired the wastegate shut.

 

[extremedsm91]

Checked timing again, and took out cas to see if that was 180 out and everything is good there. Took the turbine housing off and the flapper is seating perfect. There is a minor crack but I have seen WAY worse that boosted to atleast 16psi. I got nothing??????????????????????

 

[extremedsm91]

Help!!!!!!!!!!!!!!!!!!!!!!! Any ideas welcome. I just wasted another full day on this pile of crap.

 

[oldman]

Help!!!!!!!!!!!!!!!!!!!!!!! Any ideas welcome. I just wasted another full day on this pile of crap.

I've tried twice but you won't answer my questions.

Let's go through what you have done so far.

Originally Posted by extremedsm91

Please explain.

Did boost leak test and there is a VERY SMALL amount coming out of the throttle plate shaft and that is it.

At this point, how much pressure was the system holding and for how long?

Which turbo, bov and mbc?

 

[extremedsm91]

14b, 1g bov and cheapo mbc. I cap the turbo off and take the hose off that goes to the mbc and force air into it with my air compressor and it holds forever, there is only one leak and it is VERY minor. I have seen way worse and builds way more than 8psi.

 

[oldman]

I cap the turbo off and take the hose off that goes to the mbc and force air into it with my air compressor and it holds forever, there is only one leak and it is VERY minor. I have seen way worse and builds way more than 8psi.

1. What I mean is how much pressure during that leak test, not while boosting. A successful leak test should be 20psi for at least 30sec. I suggest repeating the leak test and have someone read the boost gauge in the cockpit and make sure that is system is truly leak free.

2. Once you're sure the system is leak free, test run with the actuator open, this should result in all out boost so careful with the throttle. If in fact you get all out boost, the mbc is probably the problem. If problem persists and again, the system is intake and exhaust leak free, the turbo would be the only thing left.

 

[Pro3racer]

I have seen this car too, and can say that there aren't any boost leaks, the tiny leak at the TB is VERY SMALL. The system holds boost fine, the blow-off valve opens when it should when doing the test. We did have someone sitting in the car reading off the boost levels. The turbo is not the problem, we are now on the 3rd, yes 3rd turbo, its not the turbo. Could it have something to do with any solenoids?

 

[oldman]

I have seen this car too, and can say that there aren't any boost leaks, the tiny leak at the TB is VERY SMALL. The system holds boost fine, the blow-off valve opens when it should when doing the test. We did have someone sitting in the car reading off the boost levels. The turbo is not the problem, we are now on the 3rd, yes 3rd turbo, its not the turbo. Could it have something to do with any solenoids?

2. Once you're sure the system is leak free, test run with the actuator open, this should result in all out boost so careful with the throttle. If in fact you get all out boost, the mbc is probably the problem. If problem persists and again, the system is intake and exhaust leak free, the turbo would be the only thing left.

Have you guys done the all out boost test yet? I suspect the mbc being the problem at this point. Make sure you also check for exhaust leaks. Any compression numbers?

 

[deusxmachina]

Has that boost controller EVER made more than 8psi? Most of the data points to that as the problem. Pull the wastegate hose off and then see if you get more than 8psi. Make sure to get off the gas quick if you do.

 

[Pro3racer]

We took the MBC out of the car completely, and went out for a test run, if the motor decided to go full boost, well, we fixed it. Even with no boost controller, only 8lbs of boost! I had to leave right before they went out and actually logged the run. Yea, with no vaccum lines, no boost control, only 8 pounds, and this has been the result on not 1 but 3 turbos!

 

[oldman]

How about compression numbers?

Possible causes :

1. Huge exhaust leak.

2. Boost leak.

3. Flapper not closed completely

4. Bad mbc (Please make sure they left the actuator nipple open, not just baypass the mbc, during their last test run)

5. Bad compression.

6. Bad turbo. On the subject of 3 different turbos, where they new or used? Did they all have this problem right from the start or did it developed after some usage?

Go back and double check the list, I'm sure the problem is there some where. Good luck.

 

[extremedsm91]

HELP!!!!!!!!!!!! Brand new 14b installed, elimanated almost all the vacume lines, no egr, no egr solenoid, no fuel pressure solenoid. Ran with wastegate acctuator unhooked and guess what. 8PSI. Compression test shows between 138-150. No codes in the ecu. 4 days wasted on this car. Never seen anything like this in my life. HELP!!!!!!!!!!!!!!!

 

[extremedsm91]

How about compression numbers?

Possible causes :

1. Huge exhaust leak.

2. Boost leak.

3. Flapper not closed completely

4. Bad mbc (Please make sure they left the actuator nipple open, not just baypass the mbc, during their last test run)

5. Bad compression.

6. Bad turbo. On the subject of 3 different turbos, where they new or used? Did they all have this problem right from the start or did it developed after some usage?

Go back and double check the list, I'm sure the problem is there some where. Good luck.

There is a downpipe on the car and an o2 dump for exhaust. I have double and triple checked everything above. NEVER seen crap like this before.

 

[Pro3racer]

quick question, when building boost, did it slowly climb to 8psi, or did it go up to 8psi like normal, then just hit a wall and not go any higher?

 

[extremedsm91]

Update. CAR IS BOOSTING!!!!!!!!!! Changed the exhaust manifold and took the downpipe completly off today and the needle on the boost guage pegged out. So I thought the manifold was bad and I put the downpipe back on, 8psi. I took it back off and it was made by the previous owner and you could not completly see in it because of a bend. Two days ago, I shoved a wire hanger through it and forced air and water through it and it seemed to be fine. NOPE. Cut it right after the flex section and the metal mesh inside the flex section let loose and bunched up making a perfect round 1 inch exhaust outlet in the flex section. What a pain in the ass.

 

[Pro3racer]

####ing awesome!