Bronco Forum - Full Size Ford Bronco Forum banner

1 - 20 of 31 Posts

·
Registered
Joined
·
17 Posts
Discussion Starter #1
What does the knock sensor on a 89' FSB 5.0 302 w/auto. trans. look like and where is it mounted? I think I found it disconnected at the rear of the engine block,thanks.
 

·
OUT OF BUSINESS / M.I.A
Joined
·
4,659 Posts
Google KS-1 or KS-2 (if I recall correctly) and you'll see what they look like. As far as buying one though, good luck. My auto parts guy sold me one a couple of years ago and said that he could not get anymore of them---from any one. Ever.

Btw, it was almost $60.00 back then....and I don't think it does $hit.

Btw 2, it should be back towards your steering wheel, on the lower intake mani......
 

·
Super Moderator
Joined
·
25,781 Posts

·
OUT OF BUSINESS / M.I.A
Joined
·
4,659 Posts
Well done Miesk. Now then, have we ever ascertained that they were actually needed or really did anything on our pre-OBDII trucks?....
 

·
Registered
Joined
·
649 Posts
I unplugged mine. It was always retarding the timing for any little noise.
 

·
Super Moderator
Joined
·
25,781 Posts
Well done Miesk. Now then, have we ever ascertained that they were actually needed or really did anything on our pre-OBDII trucks?....
yo RICKY!:thumbup

here's an update;

Knock Sensor (KS) Overview & Ford Part numbers, Bronco & Ford; "...Detect cylinder block vibrations caused by engine knock and send a signal to the computer to retard ignition timing.
FAILURE SYMPTOMS, Engine knock, loss of power, MIL light.
Check connection and signal from sensor when complaints of engine knock are present;

1996-1986 5.0L (N)/ 302 Bronco, E150, 250, F150, 250 E3AF-12A699AA,E3AZ-A Tomco PN 29021, $66.64 as of 10 JUN 2010..."
Source: by tomco-inc.com

I have an e-mail in with Tomco's John W. asking him of availability.
Tomco is excellent w/product tech info/support as well as product availability in their on-line catalogs.
---

Tomco PN 29021
---
 

·
Registered
Joined
·
27 Posts
Well the pic is correct. Mine cost $65 last week. My FSB is an "88" and the location is on top of the engine block in the rear, passenger side behind the lower intake manifold.
 

·
Super Moderator
Joined
·
25,781 Posts
Well the pic is correct. Mine cost $65 last week. My FSB is an "88" and the location is on top of the engine block in the rear, passenger side behind the lower intake manifold.
yo! thanks!:thumbup
where did you buy it?
 

·
Premium Member
Joined
·
10,000 Posts
My 86 has an IAT= intake air temp sensor and a Knock sensor which has been on there for a while, both located on the drivers side lower intake manifold, I had to have a knock hole drilled in a 92 ~ 5.0 lower intake I picked up when I cracked my 86 OEM intake by over torqing the temp gauge sensor...Duh...$75.00...PITA....

For hard to get, obsolete parts try :
John Crone, owner
Peerless Auto Parts
Artiesa Blvd
Torrance, Ca 90505

(310) 856-4810

I've always had good luck so far with John, if he can't get or find it, out of luck...

FYI, BWD Automotive makes knock sensors, I've been getting BWD products from O'Reillys but the store doesn't have the sensor...so go direct..

:thumbup
 

·
Registered
Joined
·
1,098 Posts
Sorry to dig up this old thread, but I am having pinging problems and am looking into replacing the knock sensor, what exactly does this do? does it retard the timing for a certain period of time, or until you turn it off, ect ? is there a way to test these? If I unplug it will it do anything other than throw a code or will it mess another system up?

is this a sensor that the computer tests while doing KOER test?

my rig is having poor performance and pinging, any thoughts on this would be great, its drving me nuts
 

·
Premium Member
Joined
·
10,000 Posts
How's this Brother ~ :rockon

It allows the engine to run with the ignition timing as far advanced as possible. The computer will continue to advance the timing until the knock sensor detects pinging. At that point the computer retards the ignition timing just enough for the pinging to stop.

A knock sensor assures that you're getting as much power and fuel economy as is possible from your engine.


knock sensor:
The knock sensor responds to spark knock caused by Pre-detonation of the Air/Fuel mixture. As the flame front moves out from the spark plug ignition point, pressure waves in the chamber crash into the piston or cylinder walls resulting in a sound known as a knock or ping. This is caused by using a fuel with a low octane rating, overheating, or over advanced timing. Sometimes it can be caused by hot carbon deposits on the piston or cylinder head that raise compression. A knock sensor is comprised of Piezoelectric materials; Crystals that when impacted, generate a voltage (same idea as a BBQ ignitor). This voltage is monitored by the computer, and when an irregularity is detected, the computer corrects timing in VVT (variable valve timing) engines, or triggers a DTC Diagnostic Trouble Code) in older vehicles.


Good Luck ~ :thumbup
 

·
Registered
Joined
·
1,098 Posts
thanks for the response JKossarides

so is it safe to assume that since I have a 5.0 that pings, that my knock sensor is not working properly ?
 

·
Premium Member
Joined
·
10,000 Posts
Check and see what your current BTDC timing is at, should be 10 degrees.......try bumping up the timing, see Sixlitre (ignition & timing upgrade) and see if it improves otherwise you may have to replace the "knock sensor".......IIRC it's not a critical sensor but replacing it would help stop throwing codes....PITA..etc. ...lol lol...


Good Luck ~ :thumbup
 

·
Registered
Joined
·
1,098 Posts
Unfortuantely I have already done the 6LTU and my timing is at 9 BTDC and still pings, I wish I could be at 13
 

·
Premium Member
Joined
·
3,988 Posts
Have you checked for OBD-I codes? If your Knock Sensor or associated wiring is bad you should get a KOER Code 25 (Knock not sensed during dynamic response test). Likewise, the 3-digit code is 225.

Testing would involve simulating operating conditions by connecting a timing light, starting the engine and tapping the manifold next to the Knock Sensor with a hammer. You should observe the timing retard momentarily.

If there is no response, turn the engine off with key on and check the harness connector for 5.0v reference voltage. Check for a wiring short if required.

If you need to replace the Knock Sensor, I believe that OEM is color coded to ensure the correct frequency on specific engines. I have read about Mint Green, Dark Blue and Yellow coded sensors. But having a 5.8L/6.7L, I cannot tell what color code you should have as I do not have one.

FWIW, I believe that Ford only placed them on older Trucks and Vans, although I do see them listed for the newer modular engine Trucks and Vans as well.
 

·
Premium Member
Joined
·
10,000 Posts
Am I missing something here, why can't you just "manually" turn the distributor and advance the timing to 13* with the engine running, what's the issue...?

I definately agree with Seattle FSB, run thru the tests otherwise get a new knock sensor and go from there...

Good Luck ~ :thumbup
 

·
Registered
Joined
·
1,098 Posts
Have you checked for OBD-I codes? If your Knock Sensor or associated wiring is bad you should get a KOER Code 25 (Knock not sensed during dynamic response test). Likewise, the 3-digit code is 225.

Testing would involve simulating operating conditions by connecting a timing light, starting the engine and tapping the manifold next to the Knock Sensor with a hammer. You should observe the timing retard momentarily.

If there is no response, turn the engine off with key on and check the harness connector for 5.0v reference voltage. Check for a wiring short if required.

If you need to replace the Knock Sensor, I believe that OEM is color coded to ensure the correct frequency on specific engines. I have read about Mint Green, Dark Blue and Yellow coded sensors. But having a 5.8L/6.7L, I cannot tell what color code you should have as I do not have one.

FWIW, I believe that Ford only placed them on older Trucks and Vans, although I do see them listed for the newer modular engine Trucks and Vans as well.
Thanks for the info Seattle, I am getting no codes, just pings any time under load and I am just trying to rule out all of the possibilities. I will try testing to see if the timing changes when I tap on it with a hammer.

Am I missing something here, why can't you just "manually" turn the distributor and advance the timing to 13* with the engine running, what's the issue...?
Good Luck ~ :thumbup
I have a pinging problem that I have been trying to fix ever since I owned the bronco, I wish I could set it at 13 and forget about it, but it would rattle like crazy, I am at 8 now and still ping when under load. it would be great to just be at the stock 10.

I just want to verify if the knock sensor is doing its job, before I go and replace.
 

·
Premium Member
Joined
·
3,988 Posts
I have a pinging problem that I have been trying to fix ever since I owned the bronco, I wish I could set it at 13 and forget about it, but it would rattle like crazy, I am at 8 now and still ping when under load. it would be great to just be at the stock 10.
This sounds bigger that just your Knock Sensor as it pings throughout the timing advance. I would also look at your fuel system, ICM and Distributor.
 
1 - 20 of 31 Posts
Top