Yeah I know, its not a blazer. But some blazers did come with the 2.5. So where is the knock sensor on the rear wheel drive version of the 2.5. I figured it ought to be hanging around near the distributor. Right on engine block under passenger side. Give me a hint as to where it might be cause I cant find it. Yes I did look elsewhere but I am missing something. I did not install this motor and it it not original motor. Am trying to get this completely right so the wife can use it back safely.

Heck, went to check O2 sensor cause everyone was discussing it and found mine didnt really exist anymore. Sorta broken and burned off. For something thats supposed to only last 30,000 mile it sat there way too long. Wasnt hard to get out though, seemed only finger tight. It that a new method?? [:@]

 

Pretty sure my knock sensor on my '87 2.8L is located on the passengers side of the block below the air-pump. That would be on teh front half of the block, like in front of the starter. Real bear to get at. It should be a one wire connector.

Another simple trick I use is buy a new one, look at it and then see if you can find another one like it on the engine. Follow all wiring.

 

My thoughts exactly. After posting yesterday, I went to severa; sites to order. Many times they have a picture. Only problem I ran into is that they DON"T list a part for the 2.5. Is it possible that there IS NO knock sensor?

Yes on the wiring trace. Thats why I started looking for the knock sensor. I found a wire, I looked up the color. It was a color and location for a knock sensor. I wanted to plug the darn wire it. But NO SENSOR. Your location would be perfect for the wire I found.

Thus the question becomes, is there really a knock sensor or is it possible that the darn truck is prewired for a 2.8 also? I do know the original engine in this car was a 2.5, it was simply replaced.

Sorry the question seems to be changing, but I continue to work on this vehicle and a certain amount of progress is happening.

 

Try searching for Electronic Spark Control (ESC).