i have a 89 4.3 S10. Does anyone have a photo of where it is because i cant find it in my chilton

 

It is attached to the back of the engine to the left of the distributer kind of low. I replaced my knock sensor on my 89 Jimmy last year and I had very difficult time removing. I ended up removing the throttle bracket assy. and the distributer to get more access. The problem I had was that I could not get a solid grip on it to get it to unthread it from the back of the engine. I hope you have an easier time than I did.

 

was it not accessible from under the truck?

 

its either on the drive side head,or back behind the engine.

 

No you cannot get at it from underneath due to the bel housing and firewall.

 

If you have a body lift its not as bad from under it.

 

Yup pull out your distributor and you will see it. Stick a rag in the distributor hole so no crap falls in there. Mark the dist before you pull it so you can put it back the same, and don't rotate it when its out.