Code 42 Waz Up Wit This ???
Thread Starter
Burning Brakes
Joined: Sep 2006
Posts: 1,142
Likes: 0
From: Spring Grove Illinois
Code 42 Waz Up Wit This ???
Has Anyone had a code 42 error ?? If so what did ya do to fix it..I did what the FSM stated to do and it turned out to be intermittent..But my idle is still crappy..Stumbles on start up..Hunts..Now.. I have new injectors,IAC,Tps adjusted to.54,timed to 6*BTDC..It starts it runs but the idle is all over the place..The only code is 42... Hope some ran across this B-4
Le Mans Master
Joined: Oct 2003
Posts: 6,130
Likes: 2
From: seattle WA
I believe it was a code 42 that I got when I put my dist. back in and accidentally crimped one of the wires under the dist.
with all the work you've been doing..make sure you don't have a vac. leak, and did you reset the IAC accordingly?
with all the work you've been doing..make sure you don't have a vac. leak, and did you reset the IAC accordingly?
Melting Slicks
Joined: Jun 2004
Posts: 3,032
Likes: 4
If you properly set your timing, you will have a code 42 in your ecm's history
EDIT::: Now that I rethink this... what is the code that is thrown when you disconnect the EST wire... is it a 42. I shouldn't have posted, I'm not sure now
EDIT::: Now that I rethink this... what is the code that is thrown when you disconnect the EST wire... is it a 42. I shouldn't have posted, I'm not sure now
Last edited by mikey whipreck; Dec 18, 2006 at 11:24 AM. Reason: I'm an idiot
Thread Starter
Burning Brakes
Joined: Sep 2006
Posts: 1,142
Likes: 0
From: Spring Grove Illinois
Thanks All..Yes the engine was totaly rebuilt.. I'll Check for grounds and crimped wires...The injectors are accel 24# the "86 coupe" is chipped by pcmforless so it's in the chip along with no egr and air pump..Just bugs me about the crazy idle..I'll post my findings
Le Mans Master
Joined: May 2005
Posts: 5,214
Likes: 65
From: Queensland, AUSTRALIA
Is the throttle stop screw set correctly as per the service manual?
Are all the plug leads on the correct plugs?
No vacuum leaks?
Does it do this in open and closed loop or just one or the other?
Disconnect the battery to get rid of the code and then see if it comes back if you havent done so allready.
Also try starting the engine, then stopping it after a couple seconds to see if that has any effect (that should reset the IAC)
Are all the plug leads on the correct plugs?
No vacuum leaks?
Does it do this in open and closed loop or just one or the other?
Disconnect the battery to get rid of the code and then see if it comes back if you havent done so allready.
Also try starting the engine, then stopping it after a couple seconds to see if that has any effect (that should reset the IAC)
Thread Starter
Burning Brakes
Joined: Sep 2006
Posts: 1,142
Likes: 0
From: Spring Grove Illinois
O.K. This is wierd !!
I checked everthing I could think of..Restarted the car..Same thing stumble in the idle.. when throttle cracked wouldnt miss but when it comes back down to idle it goes low then comes back up....Anyway I turned it off had a smoke restarted and the same thing..BUT the Idle went Real low almost died and went up to 600 and stayed smooth as slik..WTF..Crack the throttle and no miss..Let it run for 45 mins perfect....Does the ECM have to learn ?? Does Starting and stopping in short periods when the engine is brand new cause the ecm not to get enough info
..This is a chipped engine so Maybe ...Also does any one know what the sensor is in the radiator inbetween the trans line toward the top by the cap..Mine is leaking and I can't find it in the FSM..Thanks All..Now on to the Interior
I checked everthing I could think of..Restarted the car..Same thing stumble in the idle.. when throttle cracked wouldnt miss but when it comes back down to idle it goes low then comes back up....Anyway I turned it off had a smoke restarted and the same thing..BUT the Idle went Real low almost died and went up to 600 and stayed smooth as slik..WTF..Crack the throttle and no miss..Let it run for 45 mins perfect....Does the ECM have to learn ?? Does Starting and stopping in short periods when the engine is brand new cause the ecm not to get enough info ..This is a chipped engine so Maybe ...Also does any one know what the sensor is in the radiator inbetween the trans line toward the top by the cap..Mine is leaking and I can't find it in the FSM..Thanks All..Now on to the Interior
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Thread Starter
Burning Brakes
Joined: Sep 2006
Posts: 1,142
Likes: 0
From: Spring Grove Illinois
Le Mans Master
Joined: Feb 2006
Posts: 8,753
Likes: 9
From: Louisiana
Yep that is the low coolant level sensor. For the code 42 that is a EST code. Usually it is thrown when you set the timing after disconnecting the EST connector. Just follow the FSM and it should lead you to the problem. Not sure what to tell you if intermittant.
As for the idle problem. From reading your statements I'm about 99.9% certain that it is caused from a vacuum leak. This is what happened when I had a vac leak on mine......At start up when the engine is idling cold the idle would wonder (go up and down). As soon as the ECM went into closed loop (~140* engine temp in my guage) the wondering idle stopped. I found a big vacuum leak and fixed it, problem solved. I would suggest to go around checking all the vac lines for a open.
As for the idle problem. From reading your statements I'm about 99.9% certain that it is caused from a vacuum leak. This is what happened when I had a vac leak on mine......At start up when the engine is idling cold the idle would wonder (go up and down). As soon as the ECM went into closed loop (~140* engine temp in my guage) the wondering idle stopped. I found a big vacuum leak and fixed it, problem solved. I would suggest to go around checking all the vac lines for a open.