Anyone know why this is happening? I have a 2010 gt500 that doesn’t return to idle when I rev it. I tap the gas, the rpms go to 3,500 and don’t come down, my foot is not on the gas at any point other than the initial rev. I also noticed a little bit of oil behind the throttle body, is this normal?
Anyone know why this is happening?
- Thread starter svtmamba
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Can't speak on the rpm's hanging up but the oil is normal unless you have an oil catch can.
It’s a 2.8L Kenne Bell supercharger with a 75mm Kenne Bell throttle body. It’s tuned by paramount speed and I do have a JLT oil catch can. This happened randomly at a stop light and I have not been able to find a fix. The oil behind the throttle body can appear within a few minutes of running the way it is, it’s not like it’s been building up for a long time.
2.8L Kenne Bell supercharger, 75mm throttle body, jlt oil catch can, kooks long tube headers, msd 2 step, killer chiller heat exchanger, jlt intake, 1000cc injectors, dual VMP boost-a-pumps, devils own methanol injection, egr delete.
Should be throwing some codes, but here's something to checkout first. If that catch can is an older version, the fittings at the catch can were plastic and tend to break over time. If that happens you have a big vacuum leak. It's pretty easy to trouble shoot too. If that's your issue, contact JLT, they send you aluminum replacements for the plastic fittings.
^^^Yes, happened to my 2008 from time to time, especially when it was a little cooler outside. I lived with it for the last 10 years, it was a little bit embarrassing to pull up to a traffic light in a Torch Red Super Snake with a full 3" exhaust and be revving well beyond idle rpm. I finally decided to call Kenne Bell (the people who made the S/C and provided the tune to Shelby) and ask about it, there have been several T.B. revisions since my car came back from Shelby/Las Vegas in early 2009 and also some tune updates. I was in touch with Jim at KB, he set me up with the latest tune (which I have not added yet) and I had a spare dual 75mm updated to the latest V9. So far I have installed the T.B. only and drove my car about 60 miles each way to a car show at Sea World Orlando yesterday, it had no problems with hanging idle. Next I am going to update the tune and add a GIMME 5 CAI next.
Does your car still have the MAFia installed? I believe (but am not positive) that the newest tune will also be 750hp, my original was 725.
Jim at Kenne Bell is very helpful and it was kind of my fault for not pursuing this earlier, but the car runs so well, that an occasional high idle was not a big concern for me, plus the fact that I just turned over 1350 original miles yesterday, the car does not get out often. I knew I should investigate it further, it just took a while for me to do it.....
R
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This is pretty much always throttle body/iacv/dashpot setting related.
Yes the MAF is still installed. I’m going to check for vacuum leaks by doing smoke test but a few mechanics I spoke to said it’s unlikely. I’ve been emailing Kenne Bell back and forth but they only reply every other day or so...... I will give them a call and see if they think it’s throttle body related. Thank you for the in depth reply !
I’ve been messing around with these things with no luck but everyone has told me the same thing so I will keep pursuing...... thank you
With the tune update that KB sent me, I was told the MAFia is to be disconnected and removed and I have to install the GIMME 5 CAI in place of my original rubber Ford GT CAI.
I don't like to make too many changes at once, just in case a change introduces another issue, that is why I did the updated T.B. swap first, drove the car and then now I will do the tune update and the CAI swap.
If you have not removed your T.B. yet, you will need (or it is recommended by KB) that a ball end allen key/wrench be used to loosen/install the lower fastener closest to the blower...........If you have had your T.B. off, you know what I am talking about. That allen wrench with the ball end has a special name, I don't remember what it is but it allows you to loosen the allen head cap screw with the wrench inserted at an angle instead of straight in.
R
If you are talking about a KB blower and hanging idle issue, what Throttle Body (Twin 75mm or 168mm Mono Blade) and what version is that TB? Stamped on the back side mounting of the Twin 75, not sure on the Mono.......
Basically, approx. how old is the KB install (and tune) on your car?
R
The repair shop couldn't find the cause, so the opinion was to just replace the throttle body, and to restore the custom tune to its original state. I could instinctively know that it was not the right answer,
Then, among your replies on the forum, the problem was solved after replacing the throttle body. focused on opinions.
So I checked the throttle position sensor voltage at idle.
Voltage was measured at V1.76 and the adjusting screw was also loose! So, I searched the factory setting and adjusted it to V1.23 and fixed the adjusting screw. And the problem was solved. Good luck, and thank you. Let's all ride the 5th generation GT500 for a long, long time.
Then, among your replies on the forum, the problem was solved after replacing the throttle body. focused on opinions.
So I checked the throttle position sensor voltage at idle.
Voltage was measured at V1.76 and the adjusting screw was also loose! So, I searched the factory setting and adjusted it to V1.23 and fixed the adjusting screw. And the problem was solved. Good luck, and thank you. Let's all ride the 5th generation GT500 for a long, long time.
I have since sold the car but the issue with mine ended up being the throttle body gears. They were slightly stripped so the computer was telling the car to do the correct thing but the gears we stripped so the car couldn’t actually do it. I ended up shipping the throttle body to KB and they rebuilt it. Fixed my problem in the end but it was throttle body related.
Have contacted Kenne Bell? I have heard from Tuners that tuning that 75mm is not all that easy, it's hard to get it dialed in when starting from scratch. I have that same set up, but with the supplied KB tune. I have no issues.
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Sent from my SM-N975U1 using the svtperformance.com mobile app
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