Engine over revs since new exhaust..

[Bad Man]

...was fitted.

Hi Everyone, I had my broken Scorpion exhaust changed for a K-Tec system yesterday. Since then Ive had some problems with the engine over revving.

When I drove the car home from K-Tec I noticed the car was idling at about 1500rpm when it used to idle at about 750rpm. I wasnt too concerned, but I thought Id keep an eye on it.

I took the car out a few hours later and the car was idling normally again. Then I took the car out for a few more drives later that day and again the car idled perfectly.

All was well or so I thought...When I took the car out this afternoon the car idled perfectly until it warmed up. After about 10 minutes the engine started to pulse from 1500-3500rpm at idle. Or it would just idle at a constant 4000rpm.

I have a feeling this is an ecu problem, and Im guessing I may need a re-map. Anybody got any thoughts on this..?

 

[Phill1978]

timing needs to be advanced ?

 

[Bad Man]

Cheers for the quick reply...

Sorry Im not technical...What does advance the timing mean..?

 

[fmp_]

could the change in back pressure hav something to do with it?



or they damaged your lambda sensor while fitting it?

 

[Day]

Does the ECU not adjust accordingly?

 

[Bad Man]

I have no idea, Im gonna call K-Tec on Monday to see if they can shed any light...Thanks for the replies everyone.

 

[Mk1_MATT]

disconnect your battery for 15 mins, the nreconnect it and the ecu should adjust 2 ur new system.. hopefully

 

[edde]

The ECU should adjust the RPM to 800~900 although there are tones of variable any more than 1k though and Id wonder why.

I cannot see any reason why the exhaust change would have any impact on the the idling maybe its just coincidence /then knocked some sensor when installing it but even if they broke the labeda sensors installing the exhaust youd not get these problems.

 

[Bad Man]

OK Ive disconnected the battery, Ill leave it 15 minutes and let you know what happens...

Edde any ideas what would cause these problems?

 

[Phil 99]

might wanna leave it more than 15 minutes.

Had trouble with my engine over reving on idle, when me and a m8 tried starting my car with a flat battery, then bump starting (may have affected the exhaust in some way). When we finally got it started, it was reving too high.

Left the battery disconnected for a couple of hours, then started it and it was ok. must have affected the ECU in some way.

I know its not the same situation as yours, but I think there are some similarities

 

[Bad Man]

Cheers for the reply Phil, Ill leave it for a couple of hours then...

 

[stu8v]

Id say its more likely an ISCV problem or they have knocked something when fitting it.

 

[Phil 99]

did it work?

 

[Bad Man]

I only left the battery disconnected for an hour yesterday as I was going out.

When I reconnected it the car was idling at 2000rpm so a slight improvement.

I left the battery disconnected for 3 hours today but it still idles at 2000rpm.

Guess itll be going to the garage tomorrow.

 

[edde]

Quote: Originally posted by Bad Man on 08 January 2005

Edde any ideas what would cause these problems?

Ive just thourght the Mk1 has a proper wire on the throttle body might be worth removing the air filter and checking the throttle body is opening and closing fully as it should do. If the cable is worn or been knocked the throttle body might be staying slightly open.

 

[Bad Man]

Cheers edde, I have had problems with the throttle cable fraying before.

Usually when that happens you can put your toe under the accelerator pedal and lift it up to kill the revs. It was the first thing I tried when it started over revving.

Ill get it booked into a garage tomorrow.

Cheers for all the replies everyone...

 

[edde]

Quote: Originally posted by Bad Man on 09 January 2005

Cheers edde, I have had problems with the throttle cable fraying before.
Usually when that happens you can put your toe under the accelerator pedal and lift it up to kill the revs. It was the first thing I tried when it started over revving.

Sounds like the cable might have gone once and for all them its not that expensive to replace it with a proper new Renault one.

 

[Bad Man]

Just an update for those that are interested...

Ive just gotten my car back from the garage and it was an ISCV (Idle speed control valve) problem. Good call Stu8v.

The garage have replaced the valve and my car is running sweet once again.

 

[stu8v]

Glad i could help, it can usually be sorted by cleaning it.