Pinking

[leeways]

Hi.

I used to own a Japanese import Mk2 MR2 some 10 years ago now, and it suffered from pinking.

I got it sorted out by taking to a specialist who retarded the ignition slightly which cured it.

Anyway.

I have just bought myself another MR2, this time a later Mk2 1997 UK spec, and this one's pinking as well but in a slightly different way.

The old one used to do it all the time, but this one only does it when the engine is cold.

When it's running at it's optimum temperature, the pinking goes.

Is this a common thing with MR2's ?

Oh yes, the one I have now seems to have an aftermarket induction system.

Could this be the source of the problem this time ?

Any help appreciated.

[gazza1286]

Have you checked the timing on your new car? It could be slightly out and be causing the problem you described

AFAIK there is no issue 'pinking' with the MR2. I have noticed that viewing the timing marks from above when setting up the timing can give a false reading due to a shift in perspective. You need to compensate for this.

The best (and most accurate) method is to remove the offside rear wheel and pulley guard/tray and aim the timing light from that level.

[leeways]

Understood, but why would the pinking go away completely once the engine is warmed up

[gazza1286]

The ignition timing on the 3S engine is a bit of a hybrid. It has an ECU but at the same time there is the traditional method of altering/setting the timing by moving the distributor. The distributor has neither mechanical nor vacuum devices to advance the spark.

The ECU will advance the spark during warm-up and if this is further advanced by an incorrect distributor setting a degree of 'pinking' may result.

Once warmed up the degree of advancement may be just below that to cause the detonation. A strange one!!

[leeways]

That makes a lot of sense, thanks.

I don't suppose you live anywhere near Plymouth do you ? :)