DragonBerg

93 3vze 4x4 Sr5

I cant seem to get the truck to not ping unless the timing is set to zero!

If I set the timing to 10 truck feels fine, but will ping on the highway any time I adjust throttle.
My timing marks wander a few degrees when trying to set timing.

I jump the connectors during timing, something I dont understand is people say the idle will drop when you jump it, its confusing because jumped its at 10ish, pull the jumper and its at 8ish... so isnt the "drop" when you pull the jumper?

Ive checked my TPS tons of times and it appears to be ok, I set it by turning till idle ran high, backed off slowly till idle dropped then set it.

I dont know what else to do, it seems favorable to me to drive with it timed at 0 if no ping but Im not sure why it seems so off.

Is slight ping normal when set at 10?

Any insight or help would be greatly appreciated!

Thanks

scope103

Some have reported a failure of the rubber in the harmonic balancer, so that the outer part (with the TDC mark) rotates against the inner part (keyed to the crankshaft).

It's not too hard to check; pull the plug on #1, drop in a plastic straw, rotate the crank around the TDC mark to see if the straw agrees with where TDC is.

(You use a plastic straw instead of, say, a screwdriver to avoid damaging something if you get too energetic.)

DragonBerg

interesting... so this would mean that what Im reading as the timing mark is actually not correct? That would explain alot...

Thanks for the tip, I will have to try this.

is the truck safe to drive in this condition?

scope103

Well, "pinging" is not good; true pre-detonation can blow a hole in a piston.

What concerns me is that the Knock Sensor should retard the timing when there is knocking, no matter how messed up the base timing is.

So I don't have a complete solution.

blueknob

have you tried some 93 octane gas?