Help!! SW20 Acceleration and idle problem!
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This area is dedicated to technical discussions concerning SW20's. Please try to spell correctly because this will help people find information later if they are using search functionality. If you need assistance with your car and want to host a spanner day, please use the appropriate section of the forum: http://mr2.org.nz/phpbb3/viewforum.php?f=35 Thank you.
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- Guest of the Club.
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- First name: Mr2zilla
Help!! SW20 Acceleration and idle problem!
Hey guys a bit of troubleshooting needed!
I got a SW20 1992 with 3sgte, mostly stock other then air filter, exhaust, downpipe and running on 11psi boost which I just tweaked up from 7psi couple of weeks ago.
The other day went out for drive, revved high and boost was good however when I stopped at a petrol pump the cars idle was jumping from 1500 to 2000rpms but I turned the car off and started again the rpm stayed at 1500 and didnt dropped. When I got outta there noticed the car was making boost on the guage but wasn't pulling like before. Can notice when letting of the gas the boost compression surge is just a whoosh and car sounds a little bit quiter from the exhaust when boosting.
The car does run a bit rich since I bought it. The compression flutter was usually in 5th gear but in lower gears it used to sound like a bov (NO BOV, the outlet is blocked with a plate). No ides whats going on! is is like a leak or somthing serious??
I got a SW20 1992 with 3sgte, mostly stock other then air filter, exhaust, downpipe and running on 11psi boost which I just tweaked up from 7psi couple of weeks ago.
The other day went out for drive, revved high and boost was good however when I stopped at a petrol pump the cars idle was jumping from 1500 to 2000rpms but I turned the car off and started again the rpm stayed at 1500 and didnt dropped. When I got outta there noticed the car was making boost on the guage but wasn't pulling like before. Can notice when letting of the gas the boost compression surge is just a whoosh and car sounds a little bit quiter from the exhaust when boosting.
The car does run a bit rich since I bought it. The compression flutter was usually in 5th gear but in lower gears it used to sound like a bov (NO BOV, the outlet is blocked with a plate). No ides whats going on! is is like a leak or somthing serious??
- GDII
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- First name: Phill
Re: Help!! SW20 Acceleration and idle problem!
Check all your turbo hoses and pipes for leaks. I'd say a hose has come off.
1990 SW20 MR2 G-Limited (GEN4 3SGTE Installed)
2000 AE111R Corolla Wagon NZ New Daily
1996 AE101R Corolla Sprint NZ New Selling Soon
1990 EP81 Starlet XL (Sold)
1990 EE90 Corolla XL (Sold)
Instagram https://www.instagram.com/sw20glimited/
2000 AE111R Corolla Wagon NZ New Daily
1996 AE101R Corolla Sprint NZ New Selling Soon
1990 EP81 Starlet XL (Sold)
1990 EE90 Corolla XL (Sold)
Instagram https://www.instagram.com/sw20glimited/
- Benckj
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Re: Help!! SW20 Acceleration and idle problem!
Definitely sounds like and I take leak such as split hose. Even the original 1500 idle is high.
Starting with only 7psi boost shows there is also a problem with your stock control as should be over 10. Probably not a real concern since you have installed an aftermarket controller but an underlying issue all the same. There could be a number of protection measures that become bypassed. Can you explain your set-up a bit better including type on controller used, boost gauge and any other mods with pics?
Starting with only 7psi boost shows there is also a problem with your stock control as should be over 10. Probably not a real concern since you have installed an aftermarket controller but an underlying issue all the same. There could be a number of protection measures that become bypassed. Can you explain your set-up a bit better including type on controller used, boost gauge and any other mods with pics?
Jim Benck
90 rev 1 parts car
98 rev 5 GT- all the mods
90 rev 1 parts car
98 rev 5 GT- all the mods
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- Guest of the Club.
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- First name: Mr2zilla
Re: Help!! SW20 Acceleration and idle problem!
Boost controller looks like a GFB atomic manual boost controller and gauge is a Prosport.
Also would like to mention there's a free wire connected to the engine hood and a sensor in the front near radiator dangling freely(Can somene pls tell what are these). Pls check the attached pics.
Also would like to mention there's a free wire connected to the engine hood and a sensor in the front near radiator dangling freely(Can somene pls tell what are these). Pls check the attached pics.
- GDII
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Re: Help!! SW20 Acceleration and idle problem!
The engine lid wire should be plugged into the sensor next to it. However the only thing unplugging it like that does is make the intercooler fan run all the time. Some people like that.
The front is the temp sensor for air conditioning. It normally sits down inside the front grille next to the radiator.
With the idle, if you do have a leak, these AFM (Air Flow Meter) engines do not like vacuum leaks so any extra air that is not metered will cause extra air to be in the engine and cause a lean situation which can produce higher idle.
See if you can do a boost leak test and let us know the results.
The front is the temp sensor for air conditioning. It normally sits down inside the front grille next to the radiator.
With the idle, if you do have a leak, these AFM (Air Flow Meter) engines do not like vacuum leaks so any extra air that is not metered will cause extra air to be in the engine and cause a lean situation which can produce higher idle.
See if you can do a boost leak test and let us know the results.
1990 SW20 MR2 G-Limited (GEN4 3SGTE Installed)
2000 AE111R Corolla Wagon NZ New Daily
1996 AE101R Corolla Sprint NZ New Selling Soon
1990 EP81 Starlet XL (Sold)
1990 EE90 Corolla XL (Sold)
Instagram https://www.instagram.com/sw20glimited/
2000 AE111R Corolla Wagon NZ New Daily
1996 AE101R Corolla Sprint NZ New Selling Soon
1990 EP81 Starlet XL (Sold)
1990 EE90 Corolla XL (Sold)
Instagram https://www.instagram.com/sw20glimited/
- Alsw20
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- First name: Al
Re: Help!! SW20 Acceleration and idle problem!
Is your car running with the boost gauge just below 0?
If it is, that is defiantly a hose somewhere has a crack or come away.
If it's not, what does your warm idle show? Should be around 20 in.Hg, anything significantly closer to zero means boost leak.
If it is, that is defiantly a hose somewhere has a crack or come away.
If it's not, what does your warm idle show? Should be around 20 in.Hg, anything significantly closer to zero means boost leak.
- *84vvt
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Re: Help!! SW20 Acceleration and idle problem!
Spray some engine start around the BOV plate , to see if the vacuum leak is there the plate looks to thin to do a good job at sealing off the port .
Boosted cars are like hot women.
A little edgy, every guy wants one,
some guys can't handle them,
and if you throw a little alcohol in them they'll rock your world.
A little edgy, every guy wants one,
some guys can't handle them,
and if you throw a little alcohol in them they'll rock your world.
- Alsw20
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Re: Help!! SW20 Acceleration and idle problem!
appreciate all the replies guys!!
Ill try to check it out this weekend .(m still going to work under lockdown)
#Alsw20 the 0 reading was when the car is turned off. (guess gauge needs correction) . on Idle the reading goes around -25psi.
And i forgot to mention one thing that when that thing happened I also noticed boosting up was a bit quicker on the gauge.
however, the next morning and even today when I start the car the idle goes to normal after warming up. (after a small ride but car rides like its NA or has minimal boost while the gauge shows its going till 11psi)
Ill try to check it out this weekend .(m still going to work under lockdown)
#Alsw20 the 0 reading was when the car is turned off. (guess gauge needs correction) . on Idle the reading goes around -25psi.
And i forgot to mention one thing that when that thing happened I also noticed boosting up was a bit quicker on the gauge.
however, the next morning and even today when I start the car the idle goes to normal after warming up. (after a small ride but car rides like its NA or has minimal boost while the gauge shows its going till 11psi)
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- Guest of the Club.
- Posts: 9
- Joined: Sat Mar 28, 2020 8:50 pm
- Stomping Ground: Auckland
- Prime Mover: SW20
- First name: Mr2zilla
Re: Help!! SW20 Acceleration and idle problem!
Prob solved!! Found the turbo to inter-cooler pipe busted!! Temporary fixed it and went for a test drive!! All good now!
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- GDII
- Forum Moderator - MR2OCNZ
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- Joined: Sun Jul 10, 2011 5:13 pm
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- First name: Phill
Re: Help!! SW20 Acceleration and idle problem!
Good you found the problem. It seemed logical that it would have been a joiner based on your description. Might pay to think about replacing all the old rubber joiners in the future so it doesn't happen again. They are getting on 30+ years old.
1990 SW20 MR2 G-Limited (GEN4 3SGTE Installed)
2000 AE111R Corolla Wagon NZ New Daily
1996 AE101R Corolla Sprint NZ New Selling Soon
1990 EP81 Starlet XL (Sold)
1990 EE90 Corolla XL (Sold)
Instagram https://www.instagram.com/sw20glimited/
2000 AE111R Corolla Wagon NZ New Daily
1996 AE101R Corolla Sprint NZ New Selling Soon
1990 EP81 Starlet XL (Sold)
1990 EE90 Corolla XL (Sold)
Instagram https://www.instagram.com/sw20glimited/
- Benckj
- Forum Moderator - MR2OCNZ
- Posts: 7150
- Joined: Thu Nov 24, 2005 12:44 pm
- Stomping Ground: Otago
- Prime Mover: More than one MR2
- First name: Jim
Re: Help!! SW20 Acceleration and idle problem!
.......and use proper torque clamps as they hold better than the standard hose clamps and don’t tear into the rubber.
Jim Benck
90 rev 1 parts car
98 rev 5 GT- all the mods
90 rev 1 parts car
98 rev 5 GT- all the mods