pre detonation

[jeep90]

Dana 44 on my TJ?

i know that when you advance the timing too far you get pre detonation, pinging, rattling etc... but is this pinging sound loud or do you have to really listen for it? thanks...j

 

[PASmokeater]

You'll know it when you hear it..it's unmistakeable.....also, after you adjust..try taking the Jeep up a steep hill....sometimes the ping comes out only under load.



Rob 8)

 

[84_CJ7]

Get on the RPMs in 3rd gear shifting to 4th. If it's gonna rattle it will do it there. I agree with PASmokeater that it is unmistakable - once you associate the the actual "rattle' or "ping" with the term you will never forget it. If you're not sure, go ahead and advance it too far so you will "know" what you're listening for.

 

[Snitty]

it can often sound like you are running with a diesel engine, hense the term "dieseling"... try some higher octane fuel and see if it does any better

 

[MudderChuck]

Just my two cents worth. The Jeep motor is designed to work in the mid range, it´s pretty much a truck motor. Truck motors generally work better, due to the cam and othe factors at lower timing advance. Advancing the timing will supply a few more horses, but retarding the timing generally gives more grunt (torque).
Most emmision motors run right at the edge of detonation anyway. Timing the motor by the book works best and can save some heavy repair bills. Just changed a bent valve, in a motor that detonated, due to a vacumm leak (too lean). If I have to guess at my timing, I will generally, set it on the conservative side, to avoid major problems. I can live with a few less horses.

 

[jhiggins]

It will be very noticible and you will be able to tell easy...