Pinking

[misty]

Hi,

For a while now my engine has been pinking. I have adjusted the mixture because I thought it was running too rich, this seemed to help a lot and now it only 'pinks' when I am stuck in traffic then when clear I floor it down the motoraway and that's when it pinks, once running it's fine?

Could it still be my mixture or is it the timing? I have tried some fuel cleaner (redex) soaked in each cylinder to try and de-coke the engine.

Regards
Misty

[Rmills944]

what gas do you use? Switch gas stations and use premium if you aren't now. It sounds like you need more octane in the car.

[misty]

I use normal unleaded ron 95. Or "Optimax" (higher octane) helps but it is a bit more expensive. What damage am I doing to the engine while it is pinking?

Oh well, guess I'll have to use good 'ol optimax.
Cheers
Misty

[Zero10]

When it pings, it is detonating before it is supposed to. What actually makes the ping noise is one of a couple of things. It is usually the shock wave generated by the pre-ignition, which results in the piston slamming against the rod, which slams against the crank, and everything in-between is under a lot of stress, i.e. wrist pins, rod bearings. It can also (in bad cases) cause the skirt of the piston to strike the inside wall of the cylinder. There are a few other bad things it can do. As a general rule, pre-ignition is bad, and you should do everything in your power to prevent it.

[bigyagi]

not sure if its the same thing, but i had an annoying"knock" coming from the engine. couldent make up my mind whether it was rod knock, or detonation. only showed up when engine was stinking hot, and seemed to come and go, but could be heard plainly, and felt, if you pulled on the throttle cam, to rev the engine. long story blah blah, but in the end, i found that the afm temp sensor, and the engine temp sensor to the dme, were so far out of tolerance, that the dme was adjusting for a lean mixture, hence the knock!{many thanks to FR WILK/AFJuvat}.
it may be worth your while to check these sensors, b4 you start stripping things!
hey misty, is the m25 still a mobile parking lot? i still remember traveling to dagenham{ford}on the old A13,from grays thurrock on my honda 900! what a blast!
regards, bob.

[fast924S]

I dont now if the 924 has it but I know my 87 924S has a fuel quality switch on the DME that can help you get rid of the ping

[misty]

Big yagi,
Sometimes the M25 is a bit of a nightmare, I was also on it at the weekend heading towards Tilbury (got caught in a trafic jam for about ten minutes).
I don't think my 924 has these sesnsors. I think I will try a re-tune and use higher octane fuel. Thanks for everbodys help.
Cheers
Misty