This has been going on for awhile and I don't know really why. I'm running on 93 octane for my tuner for like almost a year now. The only time when I reall y hear it knocking is when I'm accelarating(mildly) with the a/c on. Does anybody know what the problem could be? I don't think it would have anything to do with the oil, because I'm running amsoil.

Thanks:
Matt

 

i have the same problem. only when im at low rpm at a high speed. but city driving is fine. or when i slam on the gas.

 

my 4 CYL does it only when the gas is below half a tank and no a/c on. And it does it only when I floor it...with a/c on I can tell my throttle response goes way down...

 

Those are definitely the signs of spark knock, or pre-ignition.

Usually it's caused by the timing being set to far advanced. For the StraightEdge, it's most likely the programer. Advancing the timing is where they get most of there power gains, and the 4.0 is notorious for pre-ignition. The best solution is probably to remove the programmed tune, or increase your octane rating.

Other reasons I've heard about that can cause pre-ignition, are:
Dirty injectors, Bad gas, blocked coolant chanels in the block, poor/old anitfreeze mix

Basically, anything that can make your truck's engine run hotter than normal.

I had mine fixed by getting the newest version of software for the ECM installed on the truck. I guess the version I bought mine with incorrectly set the timing too far advanced.

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I'll guess that is what I'll do today. I'll take it off and see if that works. But, I'll go ahead and change the setting, which I have 93 torque now and I'll change it to 93 horse power setting. That might work.

Also, I do have the original spark plugs in there and the truck has 51k miles on her, could that be the problem?

 

I have changed my spark plugs,changed and drained my anti-freeze, put 93 level gas in my truck with stp octane booster. and still does it!? and what setting are you talking about?

 

I have a Micro-tuner from Bamachips.

 

o something i dont have. how do i fix mine than

 

ive got similar pinging problems...right after the shift from 4th to 5th under mild throttle. Give it a little more gas and it goes away and let up a little and it goes away. I switched out the plugs and switched out the MAF. Neither of those fixed it. Seems to be less sensitive when its cold outside.

It pings on any chip setting...stock included.