knock count problem

[sytydvr]

Ok I think I found something wierd ............ I was running datamaster in my driveway, the knock retard was 18 just by revving to 2500Rpm and my knock count was going nuts... So I disconnected the sensor and the knock count was still all over the place and the Knock retard would only go to 4 while revving it to 2500.. How is this happening with the knock sensor disconnected?? could it be something else like interference? I ordered a knock sensor?

 

[truckins10]

I had the same problem that you have. I traced the KS wire all the way to the ECM and sheilded it, but it didnt seem to help Also sheilded the starter wire that seems to be very close to the KS wire, again didnt seem to help. But I definitly think it EMI, if it does it with the wire disconnected. Fern Sy#477

 

[TyMeUp]

Condition: False signals

1) Check all your electrical connections including all 'grounds' (especially ECM and Ignition grounds).

2) Swap ECM's with your Sy.

I was going to suggest "default testing" your MAP sensor on your earlier post, but this looks like a bad connection or internal ECM problem.

In case anyone out there wants to know, you can quickly check some sensor operations by disconnecting the suspect sensor (electrically) and let the ECM substitute another sensor or a pre-programmed value. If you disconnect the MAP for example, the ECM will use the TPS to do approximate fuel calculations. If you disconnect the O2 sensor, the ECM switches to 'open loop' and substitutes pre-programmed fuel trim values - (good idea to erase BLM beforehand for this).

If the engine now runs better, check that your suspect sensor is actually sensing what it should be - no vacuum leaks for the MAP; non-contaminated exhaust for the O2. If all looks good, replace the suspect sensor, it is operating out-of-range.

 

[sytydvr]

TyMeUp thanks a lot for the great info the stuff on checking sensor operations by disconnecting the suspect sensor its new to me. hope this thread helps out future truck problems for other owners

 

[93ty475]

Re: knock count problem

Ok I think I found something wierd ............ I was running datamaster in my driveway, the knock retard was 18 just by revving to 2500Rpm and my knock count was going nuts... So I disconnected the sensor and the knock count was still all over the place and the Knock retard would only go to 4 while revving it to 2500.. How is this happening with the knock sensor disconnected?? could it be something else like interference? I ordered a knock sensor?

hey sytydvr,

did you ever fix this problem? i have the same one...


servando

 

[jwaller]

Re: knock count problem

Ok I think I found something wierd ............ I was running datamaster in my driveway, the knock retard was 18 just by revving to 2500Rpm and my knock count was going nuts... So I disconnected the sensor and the knock count was still all over the place and the Knock retard would only go to 4 while revving it to 2500.. How is this happening with the knock sensor disconnected?? could it be something else like interference? I ordered a knock sensor?

thats a protection feature. if you unplug the sensor it automatically pulls out 4deg. thats the way every single one I've seen has ever worked.