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MG MGF Technical - Engine revs inconstant in traffic jam


Hi,
Today I were about 1 hour in a traffic jam, and my F engine started to rev inconstant, sometimes when I stopped the engine seams to work at about 2000rpm, then I accelerate (with the car stopped) and them the revs low to the normal 850rpm, after that I run constantly about 45minutes in highway at a normal speed (120-140 km/h) and then another small traffic jam… but here it seamed ok!?
Does this happened to any of you? any clue.
My F is a 98 1.8mpi with 52000km.

Thanks
Joao

Joao Barros Gomes

I had this problem with my F - a 96/97 model which I bought 2nd hand last August. It took 3 visits to the dealer before they eventually replaced the ECU. This solved the problem for several months, but it's just started again. Interested in any other comments.
Mark Stephens

I Mark
One more question, how much does this ECU unit cost?..., is this situation intend to aggravate or is some kind of an intermittent problem, could not be another mechanical component?
Thanks for the help
Joao
Joao Barros Gomes

Mate,
the throttle.
I'd follow Mikes advise.
Fully dismantle the thing down to pieces.
The both M3 screws which hold the flap in place need to be replaced later and secure with Loctite.

Or go for the Trophy flap mentioned to other threads.
Dieter

Yep, it's the plastic throttle valve distorting when hot, causing the throttle to stick open, thus the high revs.

Sounds like an ideal time to upgrade to the 160PS TB, lots still available at £96+VAT, please allow £5 for P&P
Dave

Dave, quite interested to read about your solution to the problem of the high revs.

I have a MGF VVC and have I think a similar problem, the car is generally fine to begin with, the problem tends to occur when you have driven the car for awhile.

It's when your lifting of the accelerator when slowing down, the car tends not to return to an idle very well, starts hiccupping for want of a better word, this used to be quite violent until my local MG dealer replaced the throttle body. Its now better but the problem persists to a lesser degree.

If i were to get an alloy throttle, is that a standard part through MG, can i just ask my MG dealer to fit one?
Tim Bennett

Check your inbox Tim :-)
Dave

... that's the true service ;)

If anyone likes to see the reason for the sticking sh*t throttle flap, see
http://www.mgfcar.de/throttle/brass_cp_0454_t.jpg

The dismantled parts which do the troubles.
The axle is made from brass and rubs on the dry rubber seal. No chance to get grease or oil or WD40 there !! Not from outside and not from inside.
Inside the body are special cheap bearings made from 'rolled' sheet metal (shining ring on the picture). This material is plated (thick) with a mixture from Teflon and lead. Works well so far but the dry rubber seal wears and derivates get on the brass axle.
Disassembling is the only chance to get it cleaned and greased.

Dieter
Dieter Koennecke

This thread was discussed between 22/03/2002 and 30/03/2002

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