Can an engine ping under medium load even if it doesn't ping under heavy load?

[myne]

So it does it at a particular rpm under any load?

Sounds like piston slap - as I mentioned.

[WHITCHY]

nah its definately a throttle point, i tested again today, its the same going up or down or on a flat, if I hold my foot at light throttle and let the revs get all the way to 6k there is no pinging noise anywhere, but as soon as I put my foot to that certain point close to 50% throttle the noise starts! as soon as I plant it to WOT it disappears, I am pretty sure it is pinging now, I was forced to run 91ron petty yesterday and the noise was still the same, but didn't dissappear at WOT, back to 98ron today and its there at med throttle position, but not at light of WOT!
Its definately something to do with the throttle position. the ecu is tuned using the TPS also instead of MAP sensor so it might have something to do with that!
Cheers.
-Whitchy-

[TurboRA28]

If it happens in neutral then i really doubt it is pinging unless the mixtures are stupidly lean (which they didn't appear to be when I checked) or the timing is really advanced.

It could be something tapping or rubbing or something. Didn't really sound like a normal pinging sound to me when we were driving.

[Draven]

nah it doesnt make the noise in neutral, its just at that certain throttle point,

10 characters

[1jzracing]

read my post earlier .... i know its a little bit double dutch but its a common issue running multi TB's and load from the TPS

i had the same thing when i first started running multi's on my beemer

when you are at half throttle with throttle bodies and load is read from TPS your actually running the engine at the equivilent of nearly wide open, your getting cylinders filling really well even though your accessing a point only half way up the ignition table so you need to run much less timing (and more fuel) in the mid range than you would on the ignition table of a MAP sensor set up, if it was reading load from MAP it would be accessing a point right up near the full load area

at wide open your getting more cold air, more fuel, and on most ignition tables less timing than part throttle so it stops pinging

other major factors are things like the runner length and so on that play funny games with the tuning on a multi TB set up too so there can be some funny waves in the tuning tables, in general the timing on mine had to be a little less than normal with the multi set up because its so efficient

just keep pulling the timimg back in the areas where its pinging ..... FIXED!!
even if it looks to be in a bit of an unusual area

[Andrew162]

I've had a similar thing happen in my Celica. it still happens even now. I reduced the timing first, down to about 7* (normally ~10*) and not only did it feel like a dog to drive, but it did nothing for the ping.

tried using 95 and 98RON fuel, neither of which helped the ping. it's more noticeable on warmer/hot days than other times, which made me think about detonation.

I replaced all accessible vacuum lines with silicone, as a lot of them had perished. it still happens around the light/mid-throttle mark, but if you plant it it disappears.

anyway I'm convinced my engine is dying... I can smell burning oil whenever I shut the car off after a run to Lismore and back, which I'm sure isn't good.

Just thought I'd share my similar experiences and throw in my 5c worth (lowest common denomination of legal tender!)