Weird Boost Issue
Originally Posted by autoxer
Let me know if anyone wants a nice how-to with pics.
Here's the problem I am having... https://www.rx7club.com/3rd-generation-specific-1993-2002-16/sequential-problems-354409/
don't race, don't need to
Joined: Oct 2002
Posts: 1,292
Likes: 1
From: Tri-Cities, WA
Glad that all worked out. So the actuator was sticking open like I thought, just not becauet the actuator was faulty, rather the solenoid. Need to move the rack off the engine, I think. Sigh... so much to do...
Good job guys!
Good job guys!
DinoDude
Joined: Feb 2002
Posts: 1,170
Likes: 0
From: Harpers Ferry, West Virginia
I just found this post this morning or I would have chimed in earlier.
Had the same problem TWICE. First time it was switched vacuum hoses like Arutha and a few months later a bad turbo control solenoid like Dave. These cars are often possessed.
Had the same problem TWICE. First time it was switched vacuum hoses like Arutha and a few months later a bad turbo control solenoid like Dave. These cars are often possessed.
Hmm... mine was working fine for a period of about three weeks after the '99 turbo install, then stopped after a oil pan reseal.. wonder if my lines are swapped, since you have to dislodge the TCA to do the pan... easy to try.
Originally Posted by arutha
I fixed mine this morning. And do I feel stupid. Hopefully the rest of you have the same problem so I won't feel as bad. 
But I had the pressure/vacuum hoses switched for the TCA. I have no idea how I had secondary boost the first try and then it fail. But anyway now I get it all the time and boy is it nice. Feels amazing. hehe
The area between the rats nest and the metal pipes by the airpump is where they weren't connected right. I went out with one T-ed and saw pressure and it appeared to work correctly in the sense of when it applied pressure and when it released it. Then I got under the car and applied pressure to that same hose with my mityvac and the arm never moved. So I tried vacuum. Then it moved and then I knew I F'ed up.
So go double check that.
But I had the pressure/vacuum hoses switched for the TCA. I have no idea how I had secondary boost the first try and then it fail. But anyway now I get it all the time and boy is it nice. Feels amazing. heheThe area between the rats nest and the metal pipes by the airpump is where they weren't connected right. I went out with one T-ed and saw pressure and it appeared to work correctly in the sense of when it applied pressure and when it released it. Then I got under the car and applied pressure to that same hose with my mityvac and the arm never moved. So I tried vacuum. Then it moved and then I knew I F'ed up.
So go double check that.
Dave,
This is VERY curious. Where the replacement solonoids you used brand new? i do notice that the condition is worse at 14 psi than it is at 10. Seems to me that the "patch" fix that PFS tried a ling time ago involved a pressure regulator that essentially limited the pressure in the line to 9-10 psi. It sorta worked... i wonder if installing something that would limit the pressure the TCS(p) sees to 9-10 psi would help out. Would it need to see 14 psi to opperate correctly if you're running 14 psi boost, or would 9-10 always be sufficient to movbe the turbo actuator?
This is VERY curious. Where the replacement solonoids you used brand new? i do notice that the condition is worse at 14 psi than it is at 10. Seems to me that the "patch" fix that PFS tried a ling time ago involved a pressure regulator that essentially limited the pressure in the line to 9-10 psi. It sorta worked... i wonder if installing something that would limit the pressure the TCS(p) sees to 9-10 psi would help out. Would it need to see 14 psi to opperate correctly if you're running 14 psi boost, or would 9-10 always be sufficient to movbe the turbo actuator?
Originally Posted by autoxer
I fixed mine too.
It was the pressure side Turbo Control solenoid. The one I replaced it with was also bad.
Both the original solenoid and the replacment still pass Mazda's check procedure (in the shop manual) with flying colors.
But here is what's happening. There is a spring in the solenoid that returns the valve back to its initial position when the power source is removed from the solenoid. Over time, the heat weakens that spring and the pressure in the line between the solenoid and the turbo control valve holds the solenoid open (the spring cannot overcome the pressure). So, the pressure can't escape and the turbo control actuator is held open when it should not be.
The solenoid I had in the car couldn't take more than about 9 psi without sticking. The original solenoid in the car couldn't take more than about 11 (I'm running 12.5). I tested several spares I had and finally found one that was happy even at 15 psi. I put it in the car and went for a test drive..... car now performs perfectly and life is good
I can post a detailed test procedure for the solenoid valve if anyone is interested. You basically need to put 12v and a ground to the solenoid, then put pressure (about 12 psi to start) on the nipple that would go to the actuator and then remove the 12v and see if the solenoid lets the pressure in the line vent. If it doesn't (or is very slow doing it), then you have a problem. Let me know if anyone wants a nice how-to with pics. You have to test it as it is used in the car, the blow through test the shop manual outlines will not work with this solenoid. A very bad solenoid can still pass that test.
Thanks for all the troubleshooting help guys. My advice, if you're having the problems described above would be to buy a NEW pressure side Turbo Control solenoid.
- Dave Disney
It was the pressure side Turbo Control solenoid. The one I replaced it with was also bad.
Both the original solenoid and the replacment still pass Mazda's check procedure (in the shop manual) with flying colors.
But here is what's happening. There is a spring in the solenoid that returns the valve back to its initial position when the power source is removed from the solenoid. Over time, the heat weakens that spring and the pressure in the line between the solenoid and the turbo control valve holds the solenoid open (the spring cannot overcome the pressure). So, the pressure can't escape and the turbo control actuator is held open when it should not be.
The solenoid I had in the car couldn't take more than about 9 psi without sticking. The original solenoid in the car couldn't take more than about 11 (I'm running 12.5). I tested several spares I had and finally found one that was happy even at 15 psi. I put it in the car and went for a test drive..... car now performs perfectly and life is good
I can post a detailed test procedure for the solenoid valve if anyone is interested. You basically need to put 12v and a ground to the solenoid, then put pressure (about 12 psi to start) on the nipple that would go to the actuator and then remove the 12v and see if the solenoid lets the pressure in the line vent. If it doesn't (or is very slow doing it), then you have a problem. Let me know if anyone wants a nice how-to with pics. You have to test it as it is used in the car, the blow through test the shop manual outlines will not work with this solenoid. A very bad solenoid can still pass that test.
Thanks for all the troubleshooting help guys. My advice, if you're having the problems described above would be to buy a NEW pressure side Turbo Control solenoid.
- Dave Disney
Originally Posted by ptrhahn
Dave,
This is VERY curious. Where the replacement solonoids you used brand new? i do notice that the condition is worse at 14 psi than it is at 10. Seems to me that the "patch" fix that PFS tried a ling time ago involved a pressure regulator that essentially limited the pressure in the line to 9-10 psi. It sorta worked... i wonder if installing something that would limit the pressure the TCS(p) sees to 9-10 psi would help out. Would it need to see 14 psi to opperate correctly if you're running 14 psi boost, or would 9-10 always be sufficient to movbe the turbo actuator?
This is VERY curious. Where the replacement solonoids you used brand new? i do notice that the condition is worse at 14 psi than it is at 10. Seems to me that the "patch" fix that PFS tried a ling time ago involved a pressure regulator that essentially limited the pressure in the line to 9-10 psi. It sorta worked... i wonder if installing something that would limit the pressure the TCS(p) sees to 9-10 psi would help out. Would it need to see 14 psi to opperate correctly if you're running 14 psi boost, or would 9-10 always be sufficient to movbe the turbo actuator?
Thread Starter
Junior Member
Joined: Nov 2001
Posts: 49
Likes: 2
From: Knoxville, TN
Here's my writeup, solenoid test procedure, and videos:
http://rx7.voodoobox.net/howto/solen...oid_check.html
http://rx7.voodoobox.net/howto/solen...oid_check.html
Call me gramps!
Joined: Jul 2003
Posts: 2,334
Likes: 0
From: Detroit, MI
Originally Posted by arutha
I fixed mine this morning. And do I feel stupid. Hopefully the rest of you have the same problem so I won't feel as bad. But I had the pressure/vacuum hoses switched for the TCA. I have no idea how I had secondary boost the first try and then it fail. But anyway now I get it all the time and boy is it nice. Feels amazing. hehe
The area between the rats nest and the metal pipes by the airpump is where they weren't connected right. I went out with one T-ed and saw pressure and it appeared to work correctly in the sense of when it applied pressure and when it released it. Then I got under the car and applied pressure to that same hose with my mityvac and the arm never moved. So I tried vacuum. Then it moved and then I knew I F'ed up.
So go double check that.
But I had the pressure/vacuum hoses switched for the TCA. I have no idea how I had secondary boost the first try and then it fail. But anyway now I get it all the time and boy is it nice. Feels amazing. heheThe area between the rats nest and the metal pipes by the airpump is where they weren't connected right. I went out with one T-ed and saw pressure and it appeared to work correctly in the sense of when it applied pressure and when it released it. Then I got under the car and applied pressure to that same hose with my mityvac and the arm never moved. So I tried vacuum. Then it moved and then I knew I F'ed up.
So go double check that.
Thread Starter
Junior Member
Joined: Nov 2001
Posts: 49
Likes: 2
From: Knoxville, TN
Originally Posted by ptrhahn
Dave,
This is VERY curious. Where the replacement solonoids you used brand new? i do notice that the condition is worse at 14 psi than it is at 10. Seems to me that the "patch" fix that PFS tried a ling time ago involved a pressure regulator that essentially limited the pressure in the line to 9-10 psi. It sorta worked... i wonder if installing something that would limit the pressure the TCS(p) sees to 9-10 psi would help out. Would it need to see 14 psi to opperate correctly if you're running 14 psi boost, or would 9-10 always be sufficient to movbe the turbo actuator?
This is VERY curious. Where the replacement solonoids you used brand new? i do notice that the condition is worse at 14 psi than it is at 10. Seems to me that the "patch" fix that PFS tried a ling time ago involved a pressure regulator that essentially limited the pressure in the line to 9-10 psi. It sorta worked... i wonder if installing something that would limit the pressure the TCS(p) sees to 9-10 psi would help out. Would it need to see 14 psi to opperate correctly if you're running 14 psi boost, or would 9-10 always be sufficient to movbe the turbo actuator?
Limiting the pressure in that line with some sort of grainger valve would be ideal if you're running high boost on a sequential system. It only needs 10 psi in those lines to make the TC actuator work. I'd rig up a grainger valve and set it to vent to atmosphere at about 10 or 11 psi. You wouldn't need to take the car apart to do it, just set the grainger valve using a compressor or mity-vac and tee it into the pressure side of the TC down near the oil pan. The pressure line is the one that hangs off the side of the TC actuator.
You might event be able to put the grainger valve at the pressure tank. None of the rest of the pressure system should need more than 10 psi to operate, and the wastegate and pre-control get their pressure straight from the turbo housing. But, if you try that take it easy the first time and see what your boost does, just in case.
I tested my car on a stock ECU (which is 10 psi) and it was better than when I was running the PFC at 12.5 psi. Based on your description above (being worse at 14 psi), I'd bet good money that your TC solenoid can't handle 14 psi.
Originally Posted by WaLieN
I'm glad you were able to fix your seq. turbos! Hehe, we basically had the same thing happen to both of us, only I didn't replace nearly as much stuff as you did.=P
Thanks Dave!
I replaced it with a brand new 'noid from Mazda and fresh lines, and it really doesn't work right even at 10-11 psi. I'm going to look into the swapped actuator hoses theory first, and then consider whether even brand-spanky new solonoids can be finnicky.
I replaced it with a brand new 'noid from Mazda and fresh lines, and it really doesn't work right even at 10-11 psi. I'm going to look into the swapped actuator hoses theory first, and then consider whether even brand-spanky new solonoids can be finnicky.
Originally Posted by autoxer
No they were not new. My original was sticking at 11 psi, the 1st replacement was sticking at 10 psi, and the final (used) one I installed works at 15 psi. None of the spares I had could take more than about 12 without sticking, except the one I wound up putting back in the car (the 15 psi one). I'd say a new solenoid would do at least that good, but no guarantee since Mazda only designed things around 10 psi.
Limiting the pressure in that line with some sort of grainger valve would be ideal if you're running high boost on a sequential system. It only needs 10 psi in those lines to make the TC actuator work. I'd rig up a grainger valve and set it to vent to atmosphere at about 10 or 11 psi. You wouldn't need to take the car apart to do it, just set the grainger valve using a compressor or mity-vac and tee it into the pressure side of the TC down near the oil pan. The pressure line is the one that hangs off the side of the TC actuator.
You might event be able to put the grainger valve at the pressure tank. None of the rest of the pressure system should need more than 10 psi to operate, and the wastegate and pre-control get their pressure straight from the turbo housing. But, if you try that take it easy the first time and see what your boost does, just in case.
I tested my car on a stock ECU (which is 10 psi) and it was better than when I was running the PFC at 12.5 psi. Based on your description above (being worse at 14 psi), I'd bet good money that your TC solenoid can't handle 14 psi.
Limiting the pressure in that line with some sort of grainger valve would be ideal if you're running high boost on a sequential system. It only needs 10 psi in those lines to make the TC actuator work. I'd rig up a grainger valve and set it to vent to atmosphere at about 10 or 11 psi. You wouldn't need to take the car apart to do it, just set the grainger valve using a compressor or mity-vac and tee it into the pressure side of the TC down near the oil pan. The pressure line is the one that hangs off the side of the TC actuator.
You might event be able to put the grainger valve at the pressure tank. None of the rest of the pressure system should need more than 10 psi to operate, and the wastegate and pre-control get their pressure straight from the turbo housing. But, if you try that take it easy the first time and see what your boost does, just in case.
I tested my car on a stock ECU (which is 10 psi) and it was better than when I was running the PFC at 12.5 psi. Based on your description above (being worse at 14 psi), I'd bet good money that your TC solenoid can't handle 14 psi.
Originally Posted by autoxer
No they were not new. My original was sticking at 11 psi, the 1st replacement was sticking at 10 psi, and the final (used) one I installed works at 15 psi. None of the spares I had could take more than about 12 without sticking, except the one I wound up putting back in the car (the 15 psi one). I'd say a new solenoid would do at least that good, but no guarantee since Mazda only designed things around 10 psi.
Limiting the pressure in that line with some sort of grainger valve would be ideal if you're running high boost on a sequential system. It only needs 10 psi in those lines to make the TC actuator work. I'd rig up a grainger valve and set it to vent to atmosphere at about 10 or 11 psi. You wouldn't need to take the car apart to do it, just set the grainger valve using a compressor or mity-vac and tee it into the pressure side of the TC down near the oil pan. The pressure line is the one that hangs off the side of the TC actuator.
You might event be able to put the grainger valve at the pressure tank. None of the rest of the pressure system should need more than 10 psi to operate, and the wastegate and pre-control get their pressure straight from the turbo housing. But, if you try that take it easy the first time and see what your boost does, just in case.
I tested my car on a stock ECU (which is 10 psi) and it was better than when I was running the PFC at 12.5 psi. Based on your description above (being worse at 14 psi), I'd bet good money that your TC solenoid can't handle 14 psi.
Limiting the pressure in that line with some sort of grainger valve would be ideal if you're running high boost on a sequential system. It only needs 10 psi in those lines to make the TC actuator work. I'd rig up a grainger valve and set it to vent to atmosphere at about 10 or 11 psi. You wouldn't need to take the car apart to do it, just set the grainger valve using a compressor or mity-vac and tee it into the pressure side of the TC down near the oil pan. The pressure line is the one that hangs off the side of the TC actuator.
You might event be able to put the grainger valve at the pressure tank. None of the rest of the pressure system should need more than 10 psi to operate, and the wastegate and pre-control get their pressure straight from the turbo housing. But, if you try that take it easy the first time and see what your boost does, just in case.
I tested my car on a stock ECU (which is 10 psi) and it was better than when I was running the PFC at 12.5 psi. Based on your description above (being worse at 14 psi), I'd bet good money that your TC solenoid can't handle 14 psi.
Don't think so... a pill would affect volume, not pressure necessarilly... you need something that would actually bleed air out of the system.
Originally Posted by HDP
So using a pill in the line wouldn't work?
Originally Posted by autoxer
Here's my writeup, solenoid test procedure, and videos:
http://rx7.voodoobox.net/howto/solen...oid_check.html
http://rx7.voodoobox.net/howto/solen...oid_check.html
don't race, don't need to
Joined: Oct 2002
Posts: 1,292
Likes: 1
From: Tri-Cities, WA
The Charge control actuator video (the 3rd one down) has his camera mounted to look at the actuator mounted on the Y-pipe, just next to the ABS heat shield. It's a CLOSE-up shot of the actuator. Cool how it just moves exactly when it oughta...
The 4th vid is looking up from the K-frame, again a close up view of the big canister type actuator you see when looking at the turbos from underneath. If you see a threaded portion to the actuator with a nut holding the clevis arm on it, that's what the video is seeing as well.
Dave, I think that's about the coolest vid I've seen around in awhile! Damien's vids are all action packed, yours NICELY informative. Makes me want to vid all the actuators just to see how they respond, nice and quick or slow, and what does the duty cycle look like? Smooth, or jerky, or what?
Very nice work, thank you for putting this on here!
The 4th vid is looking up from the K-frame, again a close up view of the big canister type actuator you see when looking at the turbos from underneath. If you see a threaded portion to the actuator with a nut holding the clevis arm on it, that's what the video is seeing as well.
Dave, I think that's about the coolest vid I've seen around in awhile! Damien's vids are all action packed, yours NICELY informative. Makes me want to vid all the actuators just to see how they respond, nice and quick or slow, and what does the duty cycle look like? Smooth, or jerky, or what?
Very nice work, thank you for putting this on here!
CCA, pressure solonoid
Hey guys, the attached vac diagram has the the CCA circled in red, and the associated pressure soloniod (letter E) circled in red as well... the vacuum 'noid is up by the UIM.
You can see two lines to the actuator. Blue is the pressure line, pink is the vacuum. You can refer to a better diagram for a good look... i had to make the picture small to get the forum to upload it. The actuator is labeled "Actuator (turbo control)"
Enjoy!
You can see two lines to the actuator. Blue is the pressure line, pink is the vacuum. You can refer to a better diagram for a good look... i had to make the picture small to get the forum to upload it. The actuator is labeled "Actuator (turbo control)"
Enjoy!
Originally Posted by ptrhahn
Hey guys, the attached vac diagram has the the CCA circled in red, and the associated pressure soloniod (letter E) circled in red as well... the vacuum 'noid is up by the UIM.
You can see two lines to the actuator. Blue is the pressure line, pink is the vacuum. You can refer to a better diagram for a good look... i had to make the picture small to get the forum to upload it. The actuator is labeled "Actuator (turbo control)"
Enjoy!
You can see two lines to the actuator. Blue is the pressure line, pink is the vacuum. You can refer to a better diagram for a good look... i had to make the picture small to get the forum to upload it. The actuator is labeled "Actuator (turbo control)"
Enjoy!
I dunno, but this picture is actually on a sticker on the underside of my hood!... too small to use though.
Originally Posted by HDP
Where is this pic in the repair manual? I looked for it last night but couldn't find it.
Haven't popped into this thread for a while, but BIG kudos to Dave for sticking with it and finding the problem! Probably would be a wise idea to test the assorted solenoids when doing a vacuum hose job or the like, now that we know a new failure mode for the solenoids!
Too bad the solenoids are sealed units - it's probably just gummed up with stuff internally that's causing the sticking. Wonder if some carb cleaner worked through them could clear one up? Might be worth experimenting with the known-bad ones, unless they've already found the trash can.
Dale
Too bad the solenoids are sealed units - it's probably just gummed up with stuff internally that's causing the sticking. Wonder if some carb cleaner worked through them could clear one up? Might be worth experimenting with the known-bad ones, unless they've already found the trash can
.Dale
Call me gramps!
Joined: Jul 2003
Posts: 2,334
Likes: 0
From: Detroit, MI
Limiting the pressure in that line with some sort of grainger valve would be ideal if you're running high boost on a sequential system. It only needs 10 psi in those lines to make the TC actuator work. I'd rig up a grainger valve and set it to vent to atmosphere at about 10 or 11 psi. You wouldn't need to take the car apart to do it, just set the grainger valve using a compressor or mity-vac and tee it into the pressure side of the TC down near the oil pan. The pressure line is the one that hangs off the side of the TC actuator.
You might event be able to put the grainger valve at the pressure tank. None of the rest of the pressure system should need more than 10 psi to operate, and the wastegate and pre-control get their pressure straight from the turbo housing. But, if you try that take it easy the first time and see what your boost does, just in case.
You might event be able to put the grainger valve at the pressure tank. None of the rest of the pressure system should need more than 10 psi to operate, and the wastegate and pre-control get their pressure straight from the turbo housing. But, if you try that take it easy the first time and see what your boost does, just in case.
Originally Posted by WaLieN
This is a great idea Dave! I'll rig up a bleed type valve (is that similar to a grainger valve?) to my pressure tank so that I don't overload my solenoids.
Which line on the pressure tank would you mount it? There is a check valve on one of the lines. Would you mount it on that line or the other and before or after the check valve? I bought a Grainger valve yesterday so I plan to do the fix this weekend.
The line w/ the check valve is the ingoing line... you'd want to do the other line that feeds the 'noids.
Sombody post specifics on the valve to use...
Sombody post specifics on the valve to use...
Originally Posted by HDP
Which line on the pressure tank would you mount it? There is a check valve on one of the lines. Would you mount it on that line or the other and before or after the check valve? I bought a Grainger valve yesterday so I plan to do the fix this weekend.
Originally Posted by ptrhahn
The line w/ the check valve is the ingoing line... you'd want to do the other line that feeds the 'noids.
Sombody post specifics on the valve to use...
Sombody post specifics on the valve to use...
