Hi!

I have a 2000 Ram pickup with 5.9 gas engine. When I put my autotap PC scan tool on it I see the spark advance varying all over the place at idle for some reason. If I look at the output of the knock sensor the voltage is jumping from about .3 volts up to just over 4 volts. Has anyone seen this or have an explanation by any chance??

Thanks! Nick

 

It is normal for the timing to fluctuate at idle.

 

Uhh, I don't believe our trucks have a knock sensor. You sure that's what you were monitoring?

 

Thanks for the responses!
Regarding the knock sensor, I will check further on that.... it is one of the selectable parameters on the Autotap screen.

Regarding the varying timing... can you explain any further? The timing on our 2000 Pontiac Grand Prix GTP is rock solid at about 20 degrees at idle.... why is the Ram jumping around? The Ram idles pretty roughly although seems to run well otherwise. I am just trying to figure out why.

Thanks for the help!!! Nick

 

Well I think you must be right because I can find no reference to a knock sensor at all in the service manual. Thought all modern fuel-injected engines used knock sensors but guess not!

Thanks again for the tip! Nick