Sequential turbo problems :(
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Im a tall midget.
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Joined: Feb 2001
Posts: 3,131
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From: So Cal, USA
Sequential turbo problems :(
My Car:
- 145,000 miles
- Rebuilt engine (~5,000 miles)
- Silicone vacuum lines
- Dale Clark's check valves (~5,000 miles)
- Ported wastegate
- HKS DP
- Catback
- Brand new turbo control solenoid (next to acv) (~10 miles)
- Silicone Y-Pipe coupling
Before my rebuild, the car had perfect boost 10-8-10 all day long. I chipped an apex seal and the car sat for roughly a year until I had the funds/time to deal with it. After proper break in, I went WOT for the first time and had no secondary boost. My primary turbo is working well for the most part.
PRIMARY TURBO:
Usually works well giving me 10psi. Other times it doesnt boost at all and I have to let off/get on the gas for a split second so it works. Something is not holding vacuum all the time.
SECONDARY TURBO:
Sometimes I get 5psi and other times I get nothing. When I do get 5psi, it quickly bleeds off until I'm left with 0psi. I can hear the turbo working but its not getting into the engine. If I get off the gas, I can hear compressor surge
I drive the car like a grandma and try to stay off of boost as much as possible because of this problem. I did the KOKO test but didnt see any significant movement at the charge control actuator. I did the KOKO test by myself so the actuator could have moved before I walked around to look at it. I also pulled off a vacuum hose from the pressure tank but didnt hear any air escaping.
I replaced the turbo control solenoid today in hopes that it would do something but the problem is still there. If anything, the situation got slightly better. I checked my vacuum hoses and everything seems to be hooked up correctly. I'm thinking a solenoid(s) went bad while it sat for almost a year. All of my engine components were stored indoors throughout the rebuild process.
Im going to test my charge control actuator tomorrow as well as the pressure and vacuum chambers. Anything else I should look at?
- 145,000 miles
- Rebuilt engine (~5,000 miles)
- Silicone vacuum lines
- Dale Clark's check valves (~5,000 miles)
- Ported wastegate
- HKS DP
- Catback
- Brand new turbo control solenoid (next to acv) (~10 miles)
- Silicone Y-Pipe coupling
Before my rebuild, the car had perfect boost 10-8-10 all day long. I chipped an apex seal and the car sat for roughly a year until I had the funds/time to deal with it. After proper break in, I went WOT for the first time and had no secondary boost. My primary turbo is working well for the most part.
PRIMARY TURBO:
Usually works well giving me 10psi. Other times it doesnt boost at all and I have to let off/get on the gas for a split second so it works. Something is not holding vacuum all the time.
SECONDARY TURBO:
Sometimes I get 5psi and other times I get nothing. When I do get 5psi, it quickly bleeds off until I'm left with 0psi. I can hear the turbo working but its not getting into the engine. If I get off the gas, I can hear compressor surge
I drive the car like a grandma and try to stay off of boost as much as possible because of this problem. I did the KOKO test but didnt see any significant movement at the charge control actuator. I did the KOKO test by myself so the actuator could have moved before I walked around to look at it. I also pulled off a vacuum hose from the pressure tank but didnt hear any air escaping.
I replaced the turbo control solenoid today in hopes that it would do something but the problem is still there. If anything, the situation got slightly better. I checked my vacuum hoses and everything seems to be hooked up correctly. I'm thinking a solenoid(s) went bad while it sat for almost a year. All of my engine components were stored indoors throughout the rebuild process.
Im going to test my charge control actuator tomorrow as well as the pressure and vacuum chambers. Anything else I should look at?
First, start with the basics. After getting a little boost from the primary, pull over before you hit 4500 and pull a line going to the pressure tank. You should feel pressurized air whoosh.
While you're in there, pull the vac tank line and verify that's also holding vacuum.
I'm guessing that if these are good you have a stuck/leaking turbo control solenoid (more likely the pressure solenoid in the rack), or possibly the turbo control actuator itself has an internal leak.
Head over to www.fd3s.net and there is an old post by Steve Wynveen. See if you can follow his troubleshooting sequence.
Dave
While you're in there, pull the vac tank line and verify that's also holding vacuum.
I'm guessing that if these are good you have a stuck/leaking turbo control solenoid (more likely the pressure solenoid in the rack), or possibly the turbo control actuator itself has an internal leak.
Head over to www.fd3s.net and there is an old post by Steve Wynveen. See if you can follow his troubleshooting sequence.
Dave
Thread Starter
Im a tall midget.
iTrader: (28)
Joined: Feb 2001
Posts: 3,131
Likes: 6
From: So Cal, USA
Back from the dead. Sorry dgeesman and namasan. My workload increased and I kind of forgot about this thread since I havent had time to really mess with the car until a few minutes ago.
I started going through the Boost Test from Auto Sport Race Tech's website. Heres what I just did:
PASSED: The car is at operating temperature per my Defi gauge. I pulled the double throttle actuator line and there was no vacuum present while idling.
PASSED: My boost gauge showed 16-17 in/Hg at idle.
FAILED: I've never been able to build 4psi at idle. Even when the car was boosting like it should. I have a silicone coupler at the Y-pipe and also at the intercooler hoses which have no tears. The hose clamps look good as well. I cant test the air bypass valve because I currently dont have anything to cap the ends with. I can only test vacuum line sized hoses & connections with my MightyVac.
FAILED: I didnt hear any air. I tried this twice after boosting on the primary (stayed under 4500rpm) turbo down the block. I didnt hear any air at all.
FAILED: Once again, no air was heard. The check valve attached to this tank is one of Dale Clark's valves. The valve is pointing towards the pressure tank and I ghetto tested it with my mouth to make sure it only flowed one way. The check valve passed the ghetto test.
When I changed my turbo control solenoid, all the vacuum lines looked like they were connected properly. I double checked them at the time and everything looked like it should comparing it to my vacuum line diagram.
Hopefully after reading my results to the boost test, you guys can point me into the right direction. I have a brand new turbo control solenoid (the one in the vacuum rack) in my room right now that I have yet to try out. I bought it just in case I needed it.
I started going through the Boost Test from Auto Sport Race Tech's website. Heres what I just did:
Originally Posted by Boost test from autosportracetech
2) Verify engine is at operating temperature.
* Remove Double Throttle Actuator vacuum line
* At operating temperature, no vacuum should be present with engine idling.
* Remove Double Throttle Actuator vacuum line
* At operating temperature, no vacuum should be present with engine idling.
PASSED: The car is at operating temperature per my Defi gauge. I pulled the double throttle actuator line and there was no vacuum present while idling.
3) Check engine vacuum at idle
* Vacuum reading should be above 15 inHg with Air Conditioner OFF. Typically 17 inHg to 19 inHg for a stock engine, and for a ported engine the vacuum readings are more in the 16 inHg range.
* Vacuum reading should be above 15 inHg with Air Conditioner OFF. Typically 17 inHg to 19 inHg for a stock engine, and for a ported engine the vacuum readings are more in the 16 inHg range.
4) Check no-load operation of Primary Turbocharger, (note that the best way to test the car for boost is step 7, but you need to pass this test/step to be able to perform test 6).
* Briefly accelerate engine to WOT in neutral, (From idle, punch the gas [WOT], get the RPMs above 5,000 but less than redline), about +4 psi should be obtained as you pass from 3,000 to 4,000 RPM.
o If you do not get this you most likely have a leak of the boosted air. Go through the Primary Turbocharger troubleshooting section.
* If get about +4 psi, then have another person watch the Turbo Pre-Control Actuator rod for movement during this test.
* Briefly accelerate engine to WOT in neutral, (From idle, punch the gas [WOT], get the RPMs above 5,000 but less than redline), about +4 psi should be obtained as you pass from 3,000 to 4,000 RPM.
o If you do not get this you most likely have a leak of the boosted air. Go through the Primary Turbocharger troubleshooting section.
* If get about +4 psi, then have another person watch the Turbo Pre-Control Actuator rod for movement during this test.
5) Check vacuum chamber's storage ability with engine off
* Pull off vacuum hose at Charge Relief Actuator
* Should hear air entering hose vacuum, re-attach hose
* Pull off vacuum hose at Charge Relief Actuator
* Should hear air entering hose vacuum, re-attach hose
FAILED: I didnt hear any air. I tried this twice after boosting on the primary (stayed under 4500rpm) turbo down the block. I didnt hear any air at all.
6) Check Pressure Tank's pressure storage ability with engine off
* Pull off one of the hoses of Pressure Tank
* Should hear air leaving tank (pressure), re-attach hose.
* Pull off one of the hoses of Pressure Tank
* Should hear air leaving tank (pressure), re-attach hose.
When I changed my turbo control solenoid, all the vacuum lines looked like they were connected properly. I double checked them at the time and everything looked like it should comparing it to my vacuum line diagram.
Hopefully after reading my results to the boost test, you guys can point me into the right direction. I have a brand new turbo control solenoid (the one in the vacuum rack) in my room right now that I have yet to try out. I bought it just in case I needed it.
Thread Starter
Im a tall midget.
iTrader: (28)
Joined: Feb 2001
Posts: 3,131
Likes: 6
From: So Cal, USA
Head over to www.fd3s.net and there is an old post by Steve Wynveen. See if you can follow his troubleshooting sequence.
Dave
Dave
If you have no vacuum at step 5 and no pressure at step 6, then you have leaks. Either leaky solenoids, leaky hoses, or broken nipples somewhere.
If you have a mityvac handy you can diagnose with speed and accuracy. Where you disconnected the vacuum hose and heard no vacuum, apply vacuum with your mityvac and look for where the air is coming in. Ditto for the pressure side.
Dave
If you have a mityvac handy you can diagnose with speed and accuracy. Where you disconnected the vacuum hose and heard no vacuum, apply vacuum with your mityvac and look for where the air is coming in. Ditto for the pressure side.
Dave
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Thread Starter
Im a tall midget.
iTrader: (28)
Joined: Feb 2001
Posts: 3,131
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From: So Cal, USA
Originally Posted by dgeesaman
If you have no vacuum at step 5 and no pressure at step 6, then you have leaks. Either leaky solenoids, leaky hoses, or broken nipples somewhere.
If you have a mityvac handy you can diagnose with speed and accuracy. Where you disconnected the vacuum hose and heard no vacuum, apply vacuum with your mityvac and look for where the air is coming in. Ditto for the pressure side.
Dave
If you have a mityvac handy you can diagnose with speed and accuracy. Where you disconnected the vacuum hose and heard no vacuum, apply vacuum with your mityvac and look for where the air is coming in. Ditto for the pressure side.
Dave
I'll probably be at Fris' shop for a few hours on Friday getting some custom brake ducts made for my FC. After that, I could probably stop by and we can mess with your car.
Thread Starter
Im a tall midget.
iTrader: (28)
Joined: Feb 2001
Posts: 3,131
Likes: 6
From: So Cal, USA
If you have no vacuum at step 5 and no pressure at step 6, then you have leaks. Either leaky solenoids, leaky hoses, or broken nipples somewhere.
If you have a mityvac handy you can diagnose with speed and accuracy. Where you disconnected the vacuum hose and heard no vacuum, apply vacuum with your mityvac and look for where the air is coming in. Ditto for the pressure side.
Dave
If you have a mityvac handy you can diagnose with speed and accuracy. Where you disconnected the vacuum hose and heard no vacuum, apply vacuum with your mityvac and look for where the air is coming in. Ditto for the pressure side.
Dave
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From: Toronto
First, start with the basics. After getting a little boost from the primary, pull over before you hit 4500 and pull a line going to the pressure tank. You should feel pressurized air whoosh.
While you're in there, pull the vac tank line and verify that's also holding vacuum.
I'm guessing that if these are good you have a stuck/leaking turbo control solenoid (more likely the pressure solenoid in the rack), or possibly the turbo control actuator itself has an internal leak.
Head over to www.fd3s.net and there is an old post by Steve Wynveen. See if you can follow his troubleshooting sequence.
Dave
While you're in there, pull the vac tank line and verify that's also holding vacuum.
I'm guessing that if these are good you have a stuck/leaking turbo control solenoid (more likely the pressure solenoid in the rack), or possibly the turbo control actuator itself has an internal leak.
Head over to www.fd3s.net and there is an old post by Steve Wynveen. See if you can follow his troubleshooting sequence.
Dave
Quick question, when testing the vacuum and pressure side with my mityvac, do I test it with the car fully warmed up and the ignition set to off? I'm going to attempt to work on the car some more on Thursday and Friday. Hopefully I can sort this out before sevenstock. Thanks for the help so far
Ignition position should be on, so that the solenoids are shut.
Dave
Thread Starter
Im a tall midget.
iTrader: (28)
Joined: Feb 2001
Posts: 3,131
Likes: 6
From: So Cal, USA
UPDATE:
I just replaced the turbo control solenoid and the charge relief solenoid (solenoids E and F on the diagram above) and the car boosts once again! My boost gauge has seen better days but its reading a solid 10psi until redline in all gears. Now, all thats left to do is figure out why the car isnt boosting 4psi while free revving the engine.
Just wanted to update the thread in case someone stumbles upon it in the future. Thanks to everyone who posted here.
I just replaced the turbo control solenoid and the charge relief solenoid (solenoids E and F on the diagram above) and the car boosts once again! My boost gauge has seen better days but its reading a solid 10psi until redline in all gears. Now, all thats left to do is figure out why the car isnt boosting 4psi while free revving the engine.
Just wanted to update the thread in case someone stumbles upon it in the future. Thanks to everyone who posted here.
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