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MG MGF Technical - lambda sensor

my 1997 mgf has 60000 miles on it recently it started to pink do you think changing the lambda sensor would help to stop it. many thanks for your thoughts
r henry

Pinking is pre-ignition - spark timing is too soon - but you might have the common HT faults which produce misfires and rough running. At this mileage you should have changed spark plugs recently. Misfires are often attributed to failing HT leads (and distributor cap if it has one) - so you may as well do the lot whilst you are "in there". It cured similar symptoms for me last year on my VVC (no disty cap).

Jeff
J Lennon

thanks i will change the leads i have recently done the dissy cap & rotor arm
r henry

I'd def change the plugs if they are "old".

1) You've stripped her down to get to the HT, so you may as well make use of your time and effort. A set of decent plugs cost £30 or there abouts.

2) The plug ends of the HT leads can be so and so's to get off, and you won't need to struggle with them again for a while!

3) If you don't fix the problem at least you know it's not the plugs nor the HT.

Jeff
J Lennon

I completly agree with Jeff.
The long life originals dont have a long life,
So replace them with quality plugs ie NGK iridiums.
while the covers off, get magnicor leads installed, and avoid having a plug fire out of the head by periodicaly taking the cover off and checking all's well.
I didn't and spent all night rehearsing my best man speach along the M6 toll hard shoulder!
oh, how i laughed.
after the plugs and leads were changed, no plinking.
2 years after that, loose plug. so dont ignore them!
Do talisker make a bad whisky hic? road trip!
John Reed

Sorry forgot,
If youve just fitted a janspeed/aftermarket manifold and sent the lambda sensor wireing behind the block instead of in front, then the wires could have been stretched / or the circuit broken, it may be worth checking the condition of the wiring.
John Reed

thanks for all advice . i did change the plugs recently so it is only the leads left to change . i have orderd a set will let you know how i get on when they arrive . thanks again
r henry

If you changed the plugs, did you check their gaps? I am sure you did, but many will simply fit new ones without thinking to check...q
Rob Bell

have fitted new ht leads and seems to be ok , ps pinking was worst in hot weather ?
r henry

turned out to be inlet manifold gasket all ok now thanks for all your input
r henry

Thanks for the feed back - I get slight rough running after a after initial start, underload and during the initial movement of the temp gauge. I'll remember your fix when I do a top end check during the winter.

Jeff
J Lennon

This thread was discussed between 21/06/2009 and 18/07/2009

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