86 B2 Knock Sensor??

[The Slider]

I recently got my 86 Bronco II back from it's 4th rebuilt transmission. The past several days it has been lack of power (not too bad) accelerating on a flat area, but going up a hill I can REALLY feel it. I ran my codes and everything was fine except the Knock Sensor (Code 25). The engine is NOT pinging, just lack power. Feels like something is holding it back or like driving straight into a HEAVY wind storm forcing the truck from going, you can feel it WANTING to go. No other codes. I have run premium w/ BG44K and no difference. Any clues? or could it be a knock sensor? I was told the 86 didn't have one.

Thanks!

 

[alwaysFlOoReD]

"There is not a knock sensor on the 86 2.9"
EDIT;
I stand corrected, see below. I was assuming the rangers and b2's had the same engine systems. oops.

 

[RonD]

Most BII's had them in 1986/7, Knock sensor is on the block just above oil pan next to start motor.

Check wires first, make sure they are not broken

This sensor is expensive unless you can find one at wrecking yard.
No, I don't know which models were the same

But this ebay listing has some "it fits": http://www.ebay.ca/itm/Ford-E6TZ-12...ash=item1c81b63391:g:IHwAAOSwmgJY54LH&vxp=mtr

If computer was programmed to use a Knock sensor, and computer detects that knock sensor is not working then it will go to Safe Spark Mode, which will show up as a lack of power
Pinging/Knocking melts pistons and valves, so bad engine damage can occur, which is why it has the Safe Mode
Using a Knock Sensor allows more aggressive spark timing for best power with 87 octane, 2.9ls without Knock sensors just had base spark timing.

This means you could switch to a computer with NO knock sensor software, Rangers around those years didn't have Knock sensor computers, and it is a plug and play swap.
Only thing to match up is EGR system(has or has not), and manual trans or automatic, computer you get must match your BII for these

 

[The Slider]

This Bronco II has been in the family since it rolled off the assembly line. It's been passed down. Something in the back of my head is saying I replaced that Knock Sensor before. I have kept every receipt I have put into this, since I became owner. I need to crawl under it and look. When I took the Bronco back for warranty work on the Bronco is when It happened. He might have pulled the wire on accident. Because at ONE time I have NO codes. ZIP, ZERO! Tomorrow I will grab a cold one and crawl under.. Keep you posted!

Thanks!

 

[The Slider]

Ok, This Bronco was made 3/86. It DOES have a Knock Sensor. It is hooked up and the wires appear to be good. How do you test the sensor?

Thanks Again!

 

[RonD]

Goggle: test knock sensor

Need a multi-meter and a "hammer" to tap on the block, simulated "knock"