hey guys...

got a question here...i own a b310 a12 5 speeder. after a top overhaul, whenever my car has not enough power, eg. climbing a slope with 3rd gear,or in any circumstances whereby the speed below its recomended gear, it produces a metal like pinging/knocking sound. it seems to get more frequent as time goes by...anyone knows whats happening? sounds like smth is getting looser day by day...

Check your timing.. That's pinging/pinking.

When you say top overhaul, I guess that the head was shaved, and the compression ratio was raised. You might also need to start using better petrol or an octane booster.

Could be a problem with the distributor also, in that it's vaccuum advance system isn't working.

Chris

Hey Nismo - your timing is too advanced. It needs to be re-set to factory specs or else you will eventually damage your engine.

Oops - Chris bet me to it and his answer is better! Must be an engineer or something...

thanks guys for the reply..

the mechanic that had done the overhaul for me told me that the timing had been adjusted way higher than the recomended factory idle rpm...he said mine's running at 1000 or 1100 rpm at idle which i think its too high...btw, my car doesnt have a tachometer..thats a huge disadvantage..the recomended idle rpm is around 600-700 rpm according to the owners manual. the mechanic said because the engine is older, if set at this rpm the car will be harder to start?

im already using RON97 petrol, what else could be better?

any other synptom whereby i can know the vacuum advance system in the distributor isnt working?

thanks in advance

You set your 'advance' with a timing light..not by idle speed

My old man taught me to set the A12 idle by turning the distributor each way, one way slows (Retards), the other speeds up (Advance). Put it in the middle. This recommendation is 'backyard boys' at it's best.

Get a timing light and set it to the factory setting.

97RON should be fine with a regular head shave.

Set the idle timing first, set the idle to 800-900rpm.

If there are still problems, address them. Saying that the 'engine is old' and setting idle higher is a way of avoiding essential repairs, or inappropriate modifications to the fuel/ignition systems.

Chris

thanks a bunch dude...

will take note of that....gonna tell the mechanic about it...

btw, i forgot to ask something..just thought about it...

what happens if i leave this metal pinging sound goin on for like a week or maybe a month more? with a few outstation drives in between? it pings and pings but it doesnt seem to lose power...will it do any harm to the engine or something will get loose?

shall i get it done b4 getting outstation or...

hmm...appreciate ur feedback guys...thanks a bunch

It is best to fix it now - your valves are suffering. Setting the timing should be inexpensive - it is a 5 min job.

whats happening is the fuel mix is igniting itself,before the spark from the spark plug.this means the piston is still coming up the bore when it meets the explosion.what you hearing
is the cylinder walls distorting.pre-ignition (pinging/pinking) can split bores & break pistons,so if you hear it,lift your foot.it's usually caused by too big a load in too high a gear,like an auto that wont kick down.putting the timing back to standard will fix the problem.

hi nismo dude.. u from malaysia? :D

i think the sound is what ppl call.. 'knocking'?
where in ECU car the cpu will auto adjust the fuel mixture

i think happened when u press too much and no power? :)