Laggy SSV/RPM?
#1
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Laggy SSV/RPM?
My 04 rx8 seems to have like a laggy SSV valve or something, If your going thought the RPM from about 5-7 it losses a little bit of power and then it will all kick in and seem fine again once it catches up to it's self. It seemed to start after my front O2 came lose under my car and dragged on the ground for a little bit, when the O2 fell out the car was way down on power and you could hear the exhaust leak so I stopped and was able to get the O2 back in. Maybe a bad O2, but then I feel like the car wouldn't run well. I did press the brake 20 times to reset that but it still has it's lag. I need to find my check engine light reader that I seamed to misplace and make sure nothing is showing there just wanted to see here encase someone might know anything
#2
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Join Date: Mar 2006
Location: 2017 Miata RF Launch Edition
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When I experienced something like this it was a bad solenoid. The solenoid was working fine electrically but it didn't seal. For me it felt like the car ran out of breath somewhere around 5500-6000 RPM and then the power would come back around 6300-6500.
I don't remember which because I pulled all three solenoids together and forgot to label them. I tested the solenoids with a MityVac hand pump to pull vacuum on the port that connects to the vacuum accumulator and one of them didn't didn't hold vacuum while it was de-energized. Replaced that solenoid and the problem went away.
https://www.rx7club.com/attachments/...renesis-ve.pdf
I don't remember which because I pulled all three solenoids together and forgot to label them. I tested the solenoids with a MityVac hand pump to pull vacuum on the port that connects to the vacuum accumulator and one of them didn't didn't hold vacuum while it was de-energized. Replaced that solenoid and the problem went away.
https://www.rx7club.com/attachments/...renesis-ve.pdf
Last edited by NotAPreppie; 05-08-2019 at 08:34 AM.
#3
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Thank you, I was think that might be the problem as well, just wasn't sure. I will check that out.
#5
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Ended up replacing all the solenoids and that has seemed to smooth out the rpm with out the drop in power. Guess the car was just never able to tell that it was failing because it still moved the SSV it just took longer to do so.
#8
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Should be noted that you can always pull a vacuum on the tank first and see if it holds before disassembling anything. There’s a short hose with a green/white check valve between the UIM and vacuum tank. The check valve needs to be checked too. Under high engine load conditions the engine is making little to no vacuum in the intake. A bad check valve will let the vacuum tank bleed down back into the intake.
Last edited by TeamRX8; 08-16-2019 at 11:14 AM.
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#9
What am I doing here?
Join Date: Mar 2006
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Should be noted that you can always pull a vacuum on the tank first and see if it holds before disassembling anything. There’s a short hose with a green/white check valve between the UIM and vacuum tank. The check valve needs to be checked too. Under high engine load conditions the engine is making little to no vacuum in the intake. A bad check valve will let the vacuum tank bleed down back into the intake.
#10
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Should be noted that you can always pull a vacuum on the tank first and see if it holds before disassembling anything. There’s a short hose with a green/white check valve between the UIM and vacuum tank. The check valve needs to be checked too. Under high engine load conditions the engine is making little to no vacuum in the intake. A bad check valve will let the vacuum tank bleed down back into the intake.
im a douche and dont know if I can pull the vacuum from the before or after the check valve,
I tried pulling it from the white 90degree elbow on the intake near the accordion tube,
and it was fine,
but I think I might just be pulling against the check valve?
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sinkas (09-05-2019)
#15
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you need to make sure that the vacuum tank that the solenoids are mounted to holds a vacuum. Either a solenoid or the seal where the solenoids fit into the tank may be leaking. There’s also a check valve on the vacuum line from the UIM to the vacuum tank (see picture above) that needs to be checked to make sure it doesn’t leak. It’s green on one side and white on the other. The green side indicates the flow direction. Make sure you don’t install it backwards.
UIM removal
https://www.rx8club.com/series-i-do-...titled-196310/
testing valve operation
https://www.rx8club.com/series-i-do-...valves-174009/
removing SSV from LIM
https://www.rx8club.com/series-i-do-...-video-184663/
**special thanks to Jon for making all these DIY threads**
.
UIM removal
https://www.rx8club.com/series-i-do-...titled-196310/
testing valve operation
https://www.rx8club.com/series-i-do-...valves-174009/
removing SSV from LIM
https://www.rx8club.com/series-i-do-...-video-184663/
**special thanks to Jon for making all these DIY threads**
.
Last edited by TeamRX8; 02-19-2020 at 11:36 AM.
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