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MG MGF Technical - Another Idling problem

Hello there,

I know the idle on a MGF is a main thread of discussions in the archives but I'm wondering if anyone has a quick answer to my problem

My car is a 2000 VVC and never idled at 800rpm's so I took it to the dealer and they changed the Throttle body. This seemed to give me 800 for about 20% of the time so I took it back. They have now replaced the VVC and Coolant sensors and I get 800 about 80% of the time. Does anyone have any ideas as I've lost faith in the dealer and I'm stuck.

It only seems to idle higher if I brake hard whilst in gear, if I take it out of gear and then brake I get the 800.

Many thanks for any advise offered.

S Jewell

>It only seems to idle higher if I brake hard whilst in gear, if I take it out of gear and then brake I get the 800.

... sounds similar to my cars idle *game*.

No VVC, which might be different, though.
99 MGF mpi, and I beleave the idle didn't work right from the beginning.

I'm on 10% currently, coming from 80% ;)
- changed the TB from plastic to the big GM body two years ago (50%)
- changed the ECT sensor recently with no improvement, but rating went up to 100% bad idle (I think cause of touching the right wire whilst the works)
- found then a bad led ECU wiring harness and re-fitment in correct location with the rivet of a cable wrap down at the ECU bracket it went better to 20%
- increased the butterfly gap with the adjustment bolt at the TB butterfly to 0,8mm resulted in 10% bad idle.

This all experianced not in a straight sequence, but with try and error. (Like your dealer does)

I think the main reason at my car was the bad led harness at the ECU connector (VVC has two of!!) and another could be a sticky IACV.

Anyway, I think no dealer has options to _analyse_ the problem, cause diagostics of the Testbook doesn't provide any result of intermittent bad working 'actuators'.

Not much help for you, the only hint is check the wires and harness fixture at the ECU. (pic from MPI)
Dieter K.

I am no expert in all this (non-mechanical individual here!!?) and have only had a 96' VVC for a month, but in that time a few problems have appeared - one of them sounds similar to the problem you have.

Once investigated, it turned out that the VVC solanoid was on the wrong way round. Mean anything to anyone out there ??

Oh, and dont ask the obvious question. It all happened courtesy of an expert twat putting the engine back together after I blew a spark plug out...for good measure someone put a knife through my window on the forecourt while it was waiting for the work to be done too...they did replace it FOC though.

Good luck....
A Smith

On second thoughts, I just looked at Dieter's website and he clearly knows just a little bit more than me.

Take his advice !!
A Smith

.. just a little bit, a little bit only ;)
And no sense of the VVC from my side.
Dieter K.

Just to expand on Deiter's comments about bad connectors and MGR Testbook....

The last time I was at MGF Centre I asked Bill to plug my car into their Testbook for a 'health Check' (MGF Centre are the only non-franchise dealer with a testbook I believe). Although I have rigorously maintained the car since new (1996) many electrical sensors were out of impedance tolerance:
Lambda Sensor (I new this anyway)
Engine bay fan
Radiator fan
Accelerator potentiometer
fuel pump

All potentially awkward failures.

Most of these will be a result of oxidised connectors and will probably only need a bit of a spray with electrical contact cleaner to get the readings within tolerance.

This little excercise just showed me the importance of a Testbook check and I suspect will answer the question of what is really causing the problems with you cars idling, or failing that goin around all the sensor connectors with a can of contact cleaner.


This thread was discussed between 03/12/2003 and 07/12/2003

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