knock sensor, detonation

Q&A regarding engines, turbos, and intercoolers and power upgrades

knock sensor, detonation

Postby Brui » Mon Aug 16, 2004 8:08 pm

what is the proper way to check if the knock sensor is in proper working order? ana how to identify the detonation before it's too late? thanks
Members don't see the above ad. Register now - it's free!
Silver 1990 ST185
Red Deer, Alberta, Canada
Brui
Club Member
 
Posts: 181
Joined: Sun Aug 08, 2004 5:01 pm
Location: Red Deer, Alberta, Canada

Postby Gary » Mon Aug 16, 2004 8:40 pm

If your knock sensor quit working, ecu will throw code 52 and go to limp mode. If the ecu detects knock, it will retard timing and limit boost.

Knocking can be caused by too advanced timing, too much boost, low octane gas, bad a/f ratio, and too hot intake air. Small/brief period of knocking (driving uphill) should not be enough to damage your engine, but hard knock and if it continues for too long, it will definite ruin the engine.
93 ST185
Image
Gary
GTFour God
 
Posts: 6430
Joined: Sun Aug 08, 2004 1:03 pm
Location: Carolina

Postby Brui » Mon Aug 16, 2004 8:56 pm

I ment to check it manually with voltmeter for resistance or so..., I have my engine a part right now,so I can check if it is working or not , is there a way? should be -- like checking other sensors...? Would ECU still do the boost cut and timing retard if I have VSV mode, FCD and running AVCR and SAFC so?
Silver 1990 ST185
Red Deer, Alberta, Canada
Brui
Club Member
 
Posts: 181
Joined: Sun Aug 08, 2004 5:01 pm
Location: Red Deer, Alberta, Canada

Postby ___Scott___ » Mon Aug 16, 2004 9:49 pm

I doubt a simple resistance check will tell you much. The knock sensor in our cars is a resonant mode sensor, so to see what it is really doing you need to perform a spectral analysis.

Comparing my new sensor to my old one yeilded identical results in a basic scope/FFT test I ran. The new sensor made a big difference in how well the car runs though.
Scott
Colorado Springs, CO - USA
SONY
Opera - The better browser
User avatar
___Scott___
Established Member
 
Posts: 2057
Joined: Mon Aug 09, 2004 5:30 pm
Location: - - USA - - Colorado Springs, CO

Postby Brui » Tue Aug 17, 2004 4:06 am

where did you get a new knock off sensor for the good price, I've heard something about the GM kit?
Silver 1990 ST185
Red Deer, Alberta, Canada
Brui
Club Member
 
Posts: 181
Joined: Sun Aug 08, 2004 5:01 pm
Location: Red Deer, Alberta, Canada

Postby Gary » Tue Aug 17, 2004 4:09 am

ATS racing sells adaptor for GM knock sensor.
93 ST185
Image
Gary
GTFour God
 
Posts: 6430
Joined: Sun Aug 08, 2004 1:03 pm
Location: Carolina

Postby ___Scott___ » Tue Aug 17, 2004 4:16 am

Brui wrote:where did you get a new knock off sensor for the good price, I've heard something about the GM kit?


I didn't, I bought a Toyota knock sensor before ATS was offering the GM adapter kit... for more than twice the price. :doh:
Scott
Colorado Springs, CO - USA
SONY
Opera - The better browser
User avatar
___Scott___
Established Member
 
Posts: 2057
Joined: Mon Aug 09, 2004 5:30 pm
Location: - - USA - - Colorado Springs, CO

Postby mototebok » Tue Aug 17, 2004 9:59 am

I'm using the ATS adapter (Thanks to Bori) and a $30 GM sensor for an 88 chevy camaro 5.0L

I also pulled out the wire from the harness for the knock sensor, and spliced in some fresh shielded cable from about 4" into the engine bay to a gm pigtail, and gave myself an extra 4" over the stock wiring for ease of installation.

Turned out good :D
-Adam
'88 Alltrac .... Got a shiny new turbo
'94 RX7 .... Other money black hole
'00 ZX6R .... Lime Green Speed Machine
User avatar
mototebok
Club Member
 
Posts: 327
Joined: Mon Aug 09, 2004 9:58 am
Location: Washington, DC or Palm Coast, FL

Postby toyotatuner » Tue Aug 17, 2004 6:40 pm

since my engine does not have a knock sensor and if i was to install a knock sensor on my 3sge motor how exactly would i intigrate that into the harness if i was to also go standalone since it has to plug in to my system? would i just use up one of the empty slots in one of the three ecu plugs?
3SGE turbo-charged baby!
toyotatuner
Club Member
 
Posts: 91
Joined: Mon Aug 09, 2004 1:45 am
Location: Melbourne

Postby ruffneck » Fri Aug 20, 2004 1:52 am

I don't have an error code coming up on my st185, but the damn thing knocks all the time when under load, like with a passenger in the car....shouldn't the ecu keep retarding timing until it stops?
ruffneck
st185 that's getting there
melb, aust.
ruffneck
Club Member
 
Posts: 294
Joined: Fri Aug 13, 2004 7:20 am

Postby Brui » Sun Aug 29, 2004 12:51 am

Gary wrote:If your knock sensor quit working, ecu will throw code 52 and go to limp mode. If the ecu detects knock, it will retard timing and limit boost.

Knocking can be caused by too advanced timing, too much boost, low octane gas, bad a/f ratio, and too hot intake air. Small/brief period of knocking (driving uphill) should not be enough to damage your engine, but hard knock and if it continues for too long, it will definite ruin the engine.
what happens when ECU goes into limp mode?
Silver 1990 ST185
Red Deer, Alberta, Canada
Brui
Club Member
 
Posts: 181
Joined: Sun Aug 08, 2004 5:01 pm
Location: Red Deer, Alberta, Canada

Postby Gary » Sun Aug 29, 2004 2:20 am

Retard timing, dump fuel, 0 boost, CEL goes off.
93 ST185
Image
Gary
GTFour God
 
Posts: 6430
Joined: Sun Aug 08, 2004 1:03 pm
Location: Carolina

Postby xgtfour » Sun Aug 29, 2004 12:55 pm

I had a knock sensor error code that I could not get rid of. Here are some troubleshooting tips.

1. If you have the initial timing to advanced to begin with the computer cannot retard the timing far enough to make it not knock. I would check your initial timing at idle. Remember you have to jump the wires at the diagnostic connector to check the timing.

2. You can also start the car with a timing light hooked up. Hit the engine lightly with a hammer (pick a part of the engine you won't break) and see if the timing retards. No retard, something is wrong.

3. You will have to take the knock sensor off for this test. You can take it off by taking the passenger side wheel off and reaching through the hole to get to the back side of the engine. You can take a multimeter, set it to voltage, put the positive lead on the male terminal of the knock sensor. Put the negative black lead on the body of the knock sensor and hit it real lightly with a hammer or wrench. It will register voltage when you do this if it is good.

If none of these things work try some octane booster and see if it makes your knocking go away.

You should be getting a CEL light if something is wrong with the knock sensor. Is your CEL light working? Does it come on with just the key on before you start it?

Darius
'88 ST165
xgtfour
Club Member
 
Posts: 22
Joined: Thu Aug 12, 2004 2:10 am
Location: Irvine, CA

Postby Brui » Sun Aug 29, 2004 5:35 pm

thanks guys for tips, all I'm trying to do -- to check if my sensor is working, cose I'm putting mods on my car so I have it all a part right now -- it's the right time to check all sensors etc.... when I had stock set up, I never had any CEL codes thrown at all,I just wanna be safe when turn up that boost dial on A-VCR
Silver 1990 ST185
Red Deer, Alberta, Canada
Brui
Club Member
 
Posts: 181
Joined: Sun Aug 08, 2004 5:01 pm
Location: Red Deer, Alberta, Canada

Postby Gary » Sun Aug 29, 2004 6:02 pm

If you wanna be on a safe side, do NOT install the FCD.
It is there to protect your engine.
93 ST185
Image
Gary
GTFour God
 
Posts: 6430
Joined: Sun Aug 08, 2004 1:03 pm
Location: Carolina

Next

Return to Performance and Power

Who is online

Users browsing this forum: Google [Bot] and 2 guests