Well I have noticed a very weird problem on my 03 EVO. There were more than a handful of times during the last couple months where when I was high RPM shifting, after letting out the clutch, the car continued to rise in RPM's like I didnt even let off the throttle! I KNOW I let off the throttle and released the clutch. RPMS just kept going up. Didnt redline are anything, since after 1-2 secs it came back down. The throttle pedal isnt sticking, do you folks think it is something in the throttle cable? When I test in the engine bay, everything looks fine moving the throttlecable by hand.

Thanks again!

Alfred

 

same happened to me, I put a spring on the butterfly to close it when my foot released from the gas pedal. went to pep boys and got a throttle spring and "rigged" it so the butterfly would close. works fine now, dont know why it happened, but now its a non-issue.
i can take a picture on where its hooked up if you want.

 

check your BOV to make sure it isn't sticking.

 

I will try that, but if you can post a picture, I would really apperciate it!

Alfred

 

Checked that and all is well. I am using an HKS SSQV.

Thanks

Alfred

 

Will try to post pix tomorrow ICE, it works for me, and I dont notice the problem anymore!

 

this has been discussed to death on that one forum. It's a common problem.

Few things.

could be your throw out bearing.

could be your intake messing with your MAF Karman vortex.

and few other theory.

search for it on engine section.

 

Thanks!

Alfred

 

I tried but found nothing. I really apperciate the pointers though, how ever I dont understand how the throw out bearing can affect it? The intake might make sense but with the throttle closed, how does the engine still get the required air to combust?

Alfred

 

People who thinks that either the clutch or throw out bearing could cause an increase in engine rpm without a downshift is just out in the blue and have no idea of how a manual transmission works, that could never happen, PERIOD!

My problems started after we installed my 3071 turbo and turned the boost up above 23-24 psi and I also solved my problem with a supplementary throttle spring and then it was gone immediately. However, some people with newer cars report a problem that might be ECU related, I don’t know any details but it might have something to do with that the ECU compensates using the idle stepping motor to keep revs up to make shifting smoother but that for sure wasn’t the case with my car.

In this thread you can find some pictures of my extra spring:

https://www.evolutionm.net/forums/sh...62#post1921062

 

It might be the BOV sticking and not blowing off quick enough when you let of the gas....

Throw your stock BOV back on and see if it stops.......

 

If the BOV was sticking which it's probably not, it would have nothing to do with this problem. I think EVOVII_SWE is on to something. The stock throttle spring does seem alittle weak.

 

Doc might not be that wrong after all, if the BOV actually were sticking it would increase the pressure on the throttle spring and make the problem worse.

 

whatever, that's not what I said. I said it was the maf sensor. Since I had that problem after replacing my clutch.

Zeus made a good sense about how the throttle body opening vs the karman vortex effecting the throttle raising since... i can't remember after that one.

 

same happens with my car...but mainly under idle...
the safcII as well as the rev counter shows the car revving to 1750 or so rpms...