knock sensor code + poor fuel econ. = ??
Thread Starter
Safety Car
Joined: Sep 2002
Posts: 4,030
Likes: 6
From: Maryland
knock sensor code + poor fuel econ. = ??
My car (1993 LT1 6spd) is putting out an ecm code 43 (no other codes anywhere) repeatedly (clear it and it comes back) plus the "service engine soon" light indicates sometimes now. This condition is accompanied by a sudden drop in fuel economy (-20%?).
Would a shot knock sensor really cause this or do I have a stuck fuel injector (mine are stock which I admittedly shouldn't be running with the heads/cam motor if I run it hard which I did, although I tried to keep the rpm down)? Shot plugs?
Anyone had this one before?
Would a shot knock sensor really cause this or do I have a stuck fuel injector (mine are stock which I admittedly shouldn't be running with the heads/cam motor if I run it hard which I did, although I tried to keep the rpm down)? Shot plugs?
Anyone had this one before?
Drifting
Joined: Apr 2005
Posts: 1,445
Likes: 0
From: Robert Lee Texas
St. Jude Donor '05-'06
Originally Posted by sothpaw2
My car (1993 LT1 6spd) is putting out an ecm code 43 (no other codes anywhere) repeatedly (clear it and it comes back) plus the "service engine soon" light indicates sometimes now. This condition is accompanied by a sudden drop in fuel economy (-20%?).
Would a shot knock sensor really cause this or do I have a stuck fuel injector (mine are stock which I admittedly shouldn't be running with the heads/cam motor if I run it hard which I did, although I tried to keep the rpm down)? Shot plugs?
Anyone had this one before?
Would a shot knock sensor really cause this or do I have a stuck fuel injector (mine are stock which I admittedly shouldn't be running with the heads/cam motor if I run it hard which I did, although I tried to keep the rpm down)? Shot plugs?
Anyone had this one before?
To check for leaking injectors, hook up a pressure guage to fuel rail, turn ing on, observe PSI, turn off, check the rate of psi drop. Mine will hold 40+ for over 30 min.
Le Mans Master
Joined: Jan 2003
Posts: 8,596
Likes: 19
From: Portland Oregon
Originally Posted by FD2BLK
Yes,
If it is setting a 43 there is somthing wrong
If it is setting a 43 there is somthing wrong
Thread Starter
Safety Car
Joined: Sep 2002
Posts: 4,030
Likes: 6
From: Maryland
Originally Posted by tjwong
Also if you set this code the PCM will retard the timing a considerable amount. Which will cause a loss in performance and fuel economy.
That's what I thought. The economy is tied to the code 43.
Is the LT4 knock sensor different than the LT1? Is there an advantage?
Safety Car
Joined: Dec 2002
Posts: 3,655
Likes: 24
From: Charleston SC
Originally Posted by sothpaw2
That's what I thought. The economy is tied to the code 43.
Is the LT4 knock sensor different than the LT1? Is there an advantage?
Is the LT4 knock sensor different than the LT1? Is there an advantage?
Thread Starter
Safety Car
Joined: Sep 2002
Posts: 4,030
Likes: 6
From: Maryland
Originally Posted by FD2BLK
Yes the LT4 or OBDII (96 LT1 uses the same sensor) sensor won't work in a OBDI car. The LT4 (OBDII) sensor is 100K and wil cause a code 43 if used in a OBDI car. Don't confuse the KM with the KS, the LT4 KM is better if you have knock problems on a LT1 because of installing RR's but if you don't have false knock even that is a waste
Safety Car
Joined: Dec 2002
Posts: 3,655
Likes: 24
From: Charleston SC
Originally Posted by sothpaw2
Ok--so to fix my code 43 I can not use the LT4 knock sensor. But the Knock module might help if I am actually getting knock due to heads/cam/rockers (well, I wasn't getting any real error codes before this incident)
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Thread Starter
Safety Car
Joined: Sep 2002
Posts: 4,030
Likes: 6
From: Maryland
Originally Posted by FD2BLK
You got it but again you only need the LT4 KM if you are having a problem with false knock
Thanks for your patience.
Le Mans Master
Joined: Jan 2003
Posts: 8,596
Likes: 19
From: Portland Oregon
Originally Posted by sothpaw2
That's what I thought. The economy is tied to the code 43.
Is the LT4 knock sensor different than the LT1? Is there an advantage?
Is the LT4 knock sensor different than the LT1? Is there an advantage?
The 96 sensors has a 100k ohm shunt resistor while the 95 and earlier has a 4k ohm resistor.
