Unusual Revving

[JackDatBoi 5]

Hey guys,

I was coming off the motorway yesterday in fifth, I needed to slow down so changed into fourth, when I put my foot on the clutch the revs started rising to about 4500, I put it in neutral and the revs would maintain 4-5000 revs! I drove for about 800m and every time I changed gears the revs would rise to 4k. I managed to pull over and stall the car to turn it off, but even in neutral the car would rev very high without my foot on the gas! Very strange.

I left the car off for around 40mins, started her up and was fine! Even went to Penrose and back with no issues.

My car is an 82 E21 - m10 1.8 carbureted.

I've done some research and think it could be a vacuum leak from the manifold - but couldn't find anything loose..
Possibly m/t fluid.. not sure

If anyone has any knowledge around this or knows anyone that could have a check it would be much appreciated.

Cheers guys.

Edited December 4, 2014 by JackDatBoi

[hybrid 1043]

Have a intake smoke test done .. will show any intake leaks after the throttle body or connecting vaccum hoses

[JackDatBoi 5]

Have a intake smoke test done .. will show any intake leaks after the throttle body or connecting vaccum hoses

Cheers mate.

[elmarco 56]

Sticky throttle cable?

[hotwire 352]

^^^^^ Sounds the most likely. Check for fraying of the inner cable, Vac leak normally wouldn't increase revs that amount.

Or, its a fault in the drive by wire throttle...

[JackDatBoi 5]

Thanks heaps guys! I'd say it's sticky throttle cable Had a look and doesn't look like any fraying has occurred.

But when I manually rev the engine while it's off, the cable becomes loose and detaches!

Cheers again.

Edited December 7, 2014 by JackDatBoi