home register FAQ memberlist calendar

Go Back   Turbobricks Forums > Mechanical > maintenance & nonperformance

Reply
 
Thread Tools Display Modes
Old 05-17-2017, 11:06 AM   #1
Uncleknucklez
bruspeed
 
Uncleknucklez's Avatar
 
Join Date: Apr 2006
Location: Sacramento, CA
Default 1-4-3 Knock Sensor code

Hey all, 1991 940 b230ft, lh2.4 (in my 240), keeps throwing the 1-4-3 code "knock sensor signal absent or faulty"

That code does not mean knock detection correct, just means that the signal is bad from the sensor?

Just want to make sure, car has a slight stutter as it dips into boost, and then throws the code, is there anything specific I should look for?
__________________
1969 142 (slow-traded)
1986 245 (slower)
1980 240 (could be quick?)
Uncleknucklez is offline   Reply With Quote
Old 05-17-2017, 11:19 AM   #2
oldschoolvolvo
Board Member
 
oldschoolvolvo's Avatar
 
Join Date: Mar 2004
Location: Lancaster, PA
Default

Your analysis is correct.

Try cleaning the connection before replacing the knock sensor.
__________________
-Mike
1998 V70 T5
1979 242 DL+T |Project Thread| |Feedback|
oldschoolvolvo is offline   Reply With Quote
Old 05-17-2017, 11:26 AM   #3
KeizerBrickGuy
Board Member
 
KeizerBrickGuy's Avatar
 
Join Date: Jun 2016
Location: Keizer, OR
Default

Are there any other codes? (Figured I'd ask) Yes, that would mean the system isn't getting a signal or is super crappy. Check the connections and grounds on the motor. Check and make sure the knock sensor is properly torqued down too. If you've kept up on maintenance, I am willing to bet the sensor is bad. Here's some more info https://www.volvoclub.org.uk/faq/Eng...ngaKnockSensor
__________________
-My car: White 1991 244, 305k miles. B230F LH2.4, AW71, R134a retro. Thrush resonator, anthracite refinished Coronas
-Wife's car: White 1990 244DL, 150k miles.B230F LH2.4, AW71, dead R12, purple refinished Virgos. ipd rear wagon overload springs.
-Work in Progress: Silver 2002 Subaru WRX wagon, 120k miles, Perrin TBE, Perrin turbo inlet, intake, and Y-pipe, GrimmSpeed cross pipe. Rebuilding EJ207 shortblock to swap in this summer.

Quote:
Originally Posted by 87_240TURBO View Post

#mclovethesenuts
KeizerBrickGuy is offline   Reply With Quote
Old 05-17-2017, 03:09 PM   #4
ZVOLV
<Master Tech>
 
ZVOLV's Avatar
 
Join Date: Nov 2002
Location: California
Default

I would inspect for pin damage at the connector.

I haven't refined my techniques here, but try tapping the block with a hammer and see if the ignition timing retards.

Or practice pulling the signal with a scope...

Or maybe practice looking at the fuel enrichment voltage.
__________________
No Start Thread
ZVOLV is offline   Reply With Quote
Old 05-17-2017, 03:13 PM   #5
KeizerBrickGuy
Board Member
 
KeizerBrickGuy's Avatar
 
Join Date: Jun 2016
Location: Keizer, OR
Default

Quote:
Originally Posted by ZVOLV View Post
try tapping the block with a hammer and see if the ignition timing retards.
This is another way to test for it. Most of us don't have lab scopes laying around, but if you find the scope fairy be sure and let her know I want two. But if you know someone that has a lab scope, get at it. I'm still betting the sensor is bad, from either corrosion or goo.
KeizerBrickGuy is offline   Reply With Quote
Old 05-17-2017, 03:32 PM   #6
brickyard92
Regular Contributor
 
brickyard92's Avatar
 
Join Date: May 2009
Location: Lawrenceville,Ga
Default

Quote:
Originally Posted by oldschoolvolvo View Post
Your analysis is correct.

Try cleaning the connection before replacing the knock sensor.
I had that same code in my 92 740.I tried cleaning the connection and block as well and there was no change.Swap it out with a new one..perfect!
__________________
Those who think they know everything annoy those of us who do.
brickyard92 is offline   Reply With Quote
Old 05-17-2017, 03:34 PM   #7
KeizerBrickGuy
Board Member
 
KeizerBrickGuy's Avatar
 
Join Date: Jun 2016
Location: Keizer, OR
Default

If you've got to replace it, might as well replace the coolant temp sensor and intake mani gasket.
KeizerBrickGuy is offline   Reply With Quote
Old 05-17-2017, 04:34 PM   #8
ZVOLV
<Master Tech>
 
ZVOLV's Avatar
 
Join Date: Nov 2002
Location: California
Default

Quote:
Originally Posted by KeizerBrickGuy View Post
This is another way to test for it. Most of us don't have lab scopes laying around, but if you find the scope fairy be sure and let her know I want two. But if you know someone that has a lab scope, get at it.
I will sell you my $80 Hantek for $60 shipped. It reverted back to Mandarin or Cantonese.

https://www.picoauto.com/library/aut.../knock-sensor/
ZVOLV is offline   Reply With Quote
Old 05-17-2017, 04:36 PM   #9
KeizerBrickGuy
Board Member
 
KeizerBrickGuy's Avatar
 
Join Date: Jun 2016
Location: Keizer, OR
Default

That's a heck of an offer ZVOLV...but as of current, I must keep my spending tight with a baby due in September.
KeizerBrickGuy is offline   Reply With Quote
Old 05-17-2017, 10:36 PM   #10
Uncleknucklez
bruspeed
 
Uncleknucklez's Avatar
 
Join Date: Apr 2006
Location: Sacramento, CA
Default

Problem solved. Pay attention to the wire colors folks, had the egr plug on the knock sensor, and vice versa. Why the same connectors so close together???

This thing runs pretty goooood now.

Thanks all.
Uncleknucklez is offline   Reply With Quote
Old 05-17-2017, 11:06 PM   #11
philski o'flood
Board Member
 
philski o'flood's Avatar
 
Join Date: Nov 2005
Location: San Diego
Default

yes!
philski o'flood is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On

Forum Jump


All times are GMT -4. The time now is 03:42 AM.

Powered by vBulletin® Version 3.8.9
Copyright ©2000 - 2017, vBulletin Solutions, Inc.