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MG MGF Technical - 2002 160VVC - Power Loss

Can anybody help explain or resolve a problem I have experinced since I purchased my 2002 TF 160 VVC, last May.

On the occasions when I accelerate extremely hard in 3rd gear to overtake, the engine suddenly falters and dies at around 6,000 revs, requiring me to declutch and change up. The engine then instantly recovers, (it feels a bit like fuel starvation).

Apart from this fault, the car behaves perfectley in every other way.(Mileage is currently at 28K).

Has anybody else experienced this or could advise what the problem may be.


Many Thanks
Ian
Ian

Is this only in 3rd? Sounds a lot like the rev-limiter, but it shouldn't cut in on a VVC until 7,200rpm. Daft question - are you positive it's a VVC?

Cheers,
Tim
T Jenner

I must admit, its only when I'm trying to overtake another car quickly on a country lane, that it shows itself up, hence the 3rd gear.
Perhaps I am closer to 7,200 revs than I thought, (it accelerates so fast its hard to tell especially when watching the road as well).
It is definately a 160 VVC engine though.

Regards
Ian

IR Sever

If it does this in any gear at the same rev limit, is it possible the ECU is for a mpi and not a VVC ? sounds like a testbook is needed to check things out.
M.
mike

Hi mike
how do you go with the laws on haveing an old car in singapore i have been there a lot over the years and dont think i have ever seen an mg and all your cars seam to only be a few years old i no you have a very tight rego system in place
Andrew australia
AR Cayzer

Hi Andrew,

The costly COE (cert. of entitlement) has to be renewed every 10 yrs, so it pays for joe public to get a new car, having said that there are many classic cars including MG's, morris minors, mini's jags etc. sitting in apartment basements and seen occasionaly on the road.
As for me I've an MGF trophy 160 and a MG Z801+ sitting at home in the UK waiting foe my return at the end of this month, the "F" has been stored in the garage since April 2005, but the 'Z' is now back on the road as Viv (my wife) has returned to the UK to get the place ready for myn triumphant return ha ha.

Mike
Mike

Hi mike
i new there was some funny and costly things with haveing an older car there we had dinner one night at newtons circus and the family at our table the gent was a car salesman he tryed to explan the rego rules .
have you been there since 2005 you are going to frezz when you get home
Andrew
AR Cayzer

Hi Andrew,
Was home for two weeks over Christmas and yes the first couple of days walking the dog on the beach was freezing, the cold went straight through my trousers, so Feb I know will be even worse :-( and yes I've been here since '05.
Mike
Mike

Have heard of this problem before, but it normally effects the rev limit in all gears. It seems the rev limiter on a VVC will cut in at around 6k RPM for a number of reasons:

a) Camshaft position sensor fault
b) VVC Hydraulic control Valve fault (or the two wiring connecters have been refitted wrong way round, which is quite common)
c) Faulty/Incorrectly timed VVC mechanisms

Having the car checked on Testbook is probably the best approach IMO.
Steve White

Thanks Steve.

I think you could be on the right track.
I've done a bit more research since my original message. The engine does cut out in all gears at around 5,500 rpm. A definite Rev Limiter problem.
I have spent the afternoon looking over the engine and have found the IAT sensor was not connected. I have found a sensor under the thermostat with only a Brown/Pink wire connected, the Yellow/Green wire is cut, or maybe shouldn't be connected???. The point you mention about two connectors being refitted incorrectly, I will check tomorrow. It looks like somebody has had the head off and made a very poor job of reassembly.

Thanks for your suggestions.

Ian
IR Sever

Hi,

brown/pink is always a power feed only.

So the yellow/green must get connected. This one either relates to the Throttle Position Sensor or to the Oxygen Sensor ?


Dieter

Hi Dieter
I'm a bit confused, the sensor the connector is attached to appears to be under the theromstat assembly. I cannot find a mention of it in the manual.
The Yellow/Green wire is cut about 30mm down. (please se photo).
Would this sensor relate to either the Throttle Position Sensor or to the Oxygen Sensor??.
Or maybe the connectors in the wrong place?.
(please refer photo).

Many thanks
Ian


IR Sever

This thread was discussed between 02/01/2008 and 05/01/2008

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