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MG MGF Technical - 160 VVC - Rev Limiter @ 5,500 rpm

I am looking for a bit more advice on the above. Having spent a lot of time recentley trying to find out why my rev's are limited to 5,500 rpm on my (3rd hand) 2002 - 160 VVC.
Conclusions are, the head has been removed at some time,(probably head gasket)and I found the IAT sensor was not connected.

Can anybody advise:-

(1) Having reconnect the IAT, and assuming that the rev limit problems was solely due to the IAT being disconnetced.
Should the ECU revert back to normal running on reconnection?, or does the car have to go in for Testbook work?.

(2) Assuming I have to dig deeper to find the problem, ie, it has been indicated that the VVC bits may have been reassembled badly.
Can this work be carried out by remving the cam covers?, or does the cylinder head have to come off again?.

Would appreciate any guidance on the above.

Many thanks in advance
Ian
IR Sever

Or there has been a 'bodge up' of a MPi which if I remember correctly has a rev limit of 5500!
Ted Newman

6250 for the mpi iirc
Will Munns

Hi, i had the same problem with my VVC . It turned out that the car had a knackered cat and simply would not rev beyond 5500. Simple change over and back to 7000+ was obtained.
Jamie
J P eirson

My '96 mpi is redlined at 6800 which it will reach, although the last 500-odd rpm arrive slower than the preceding 500. Perhaps one day I'll get the TF135 cams which improve the top-end breathing, although I might have to cross my fingers that the big-ends are still up to it!
Mike Cunningham

MPi red line 6750rpm, VVC 7250rpm.

Mike, my MPi with a pair of 135 cams (and little bit of head porting, I must admit) absolutely lunges for the red line now. Well worth it :o)

Ian, can you describe what happens when you reach 5500rpm? Are we talking about hitting the rev-limiter, or is there a mis-fire? Or does the car simply loose power and gains engine speed very slowly? Knowing what happens might help narrow down what is wrong- but perhaps something to look at is cam timing and the operation of the VVC actuator... Or perhaps an intermittent signal from the crank position sensor.

I assume that the simple items have already been attended to - like the ignition HT leads?
Rob Bell

Hi Rob

Since my first post, I have spent some time driving up and down the back lanes in 2nd & 3rd gear carefully watching the rev counter, I can conclude it is a definite rev-limiter problem.
As soon as I hit 5,500 the engine dies, it then picks up again as the revs drop and if I've still got my foot on the accelerator it picks up and dies when I hit 5,500 again, (and so on ad infinitum). When it dies it is as if the fuel has been cut off.

Having made a few enquiries since, combined with the tips on this page, I'm resigned to the fact that it is going to be either a VVC mechanism, cam timing sensor of cat problem.
I need to get the engine checked on one of these analiser things.

Just got to find one local to Bridgnorth.

Thanks for your guidance.

Ian
IR Sever

It could be that your VVC is stuck on the short period setting, may be something to do with the hydraulic actuator or sensors. You need to find a good specialist - don't know any former Rover dealers in you area
Paul Hollingworth

This thread was discussed between 07/01/2008 and 14/01/2008

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