Topic: knock sensor?

[kauaijeep]

Is there a knock sensor used in the 1991 2.5l yj? If it does, then where would it be located? Thanks.

[Jeffy]

Is there a knock sensor used in the 1991 2.5l yj? If it does, then where would it be located? Thanks.

I don't believe it does.

[yellowta]

I think the knock sesnor is an OBD-II item not put in until 96' I think. Could be wrong though

[Jeffy]

I think the knock sesnor is an OBD-II item not put in until 96' I think. Could be wrong though

They used knock sensors on the earlier 4.2L's and early Renix 4.0L's.  I think the 3.7L uses one also.

[kauaijeep]

Thanks for the info. By the way is there any way to adjust the timing on a '91 yj?

[yellowta]

Valve timing or ignition timing? For one, you would have to buy a timing chain and gear set that would allow you to see how much you were retarding or advancing the timing... or you could be brave and just mount the stock gear one or two teeth off of tdc. Dangerous I would imaging. Ignition should just be a matter of loosening the hold down clamp and turning the distributor while monitering the engine with a timing light :roll:   I think  

[Jeffy]

I'm thinking he's refering to engine timing which is controlled by the PCM.  Although you can adjust it a little with the CPS.  You'll have to modify the sensor.

[kauaijeep]

Sorry for not being more specific, but yes it was ignition timing that I was asking about and I will try to slot out the holes on the cps and move it opposite of the engine rotation as posted on another topic. Thanks.