Hey guys,
I have searched and searched but cannot find a definitive answer to what the knock sensor resistance is supposed to be for my truck. Truck is a 90 4.3l manual trans with 16144288 ecm and external esc.
I don't have the original one to measure and the one that I got from the auto parts store is 100k. My knock counts are really high and the truck has no power but runs good otherwise (definitely feels like timing is being pulled). My Haynes manual says it should be 3.9k. My neighbour has a 90 with a 305 and it had a 3.9k and when he replaced his he was also given a 100k. Would running a 100k instead of a 3.9k give high knock counts?
I can't figure out if I need to get a different knock sensor or desensitise it. If anyone knows for certain what the resistance is supposed to be for this set up I would be greatly appreciative. I bought this truck running like crap and got everything ironed out except for the excessive knock and wish to God I had not thrown out the original knock sensor. I've learned a lot since that mistake. I never would have thought that it would be so difficult to find out for certain which sensor this truck should have.
Any information is appreciated.

 

Being a C3 TBI ECM (external ESC module) the knock sensor should be 100K ohms.

The 3.9K ohms knock sensors are used with ECMs that have the knock filter internal to the ECM.

Be sure to torque it to 11 - 14 ft/lbs, which isn't much.

RBob.

 

Thank you
Looks like I do have the right one. I guess it's time to desensitize.