Code 34 but not the MAF - any experts handy ?
Thread Starter
Burning Brakes
Joined: Dec 2002
Posts: 1,199
Likes: 4
From: Cairns Australia
Code 34 but not the MAF - any experts handy ?
My 88 vette has thrown code 34 a few times in the last 6 weeks.
That is supposed to point to the MAF - relays or Maf itself but the the engine runs fine, no problems, fuel economy normal. The relays were replaced 18 months ago.
So I don't think it has anything to do with the MAF
The code comes back ONLY when I start the engine too quickly. Once the engine is warm it goes away on a restart.
There is only one symptom when the SES light is on -the overdrive is different - when I back off the throttle the gears don't freewheel like they usually do. Definitely very different to when the SES light is off.
When I wait 10 seconds after turning the ignition on, I hear a creaking from behind the dash - must be an aircon or heater door moving. Once I hear that noise I start the engine and no SES light.
Any ideas ?
S'Nut
That is supposed to point to the MAF - relays or Maf itself but the the engine runs fine, no problems, fuel economy normal. The relays were replaced 18 months ago.
So I don't think it has anything to do with the MAF
The code comes back ONLY when I start the engine too quickly. Once the engine is warm it goes away on a restart.
There is only one symptom when the SES light is on -the overdrive is different - when I back off the throttle the gears don't freewheel like they usually do. Definitely very different to when the SES light is off.
When I wait 10 seconds after turning the ignition on, I hear a creaking from behind the dash - must be an aircon or heater door moving. Once I hear that noise I start the engine and no SES light.
Any ideas ?
S'Nut
Thread Starter
Burning Brakes
Joined: Dec 2002
Posts: 1,199
Likes: 4
From: Cairns Australia
Hi Bogus, I have the workshop manuals, but I don't think this is the MAF.
I can't see why the freewheeling part of the overdrive should be disabled. By freewheeling I mean that when you back off the throttle the car 'coasts' rather than slows down as a geared car would.
It happened again today. First start was OK, 2nd start OK - 3 hour break, next start SES light came on (even though I waited 10 secs) Car ran fine. Restart 30 mins later - no SES light.
These things are weird till you find out what they are.
S'nut
I can't see why the freewheeling part of the overdrive should be disabled. By freewheeling I mean that when you back off the throttle the car 'coasts' rather than slows down as a geared car would.
It happened again today. First start was OK, 2nd start OK - 3 hour break, next start SES light came on (even though I waited 10 secs) Car ran fine. Restart 30 mins later - no SES light.
These things are weird till you find out what they are.
S'nut
Thread Starter
Burning Brakes
Joined: Dec 2002
Posts: 1,199
Likes: 4
From: Cairns Australia
Yes, thanks Bogus, I thought that was what you meant and it is logical.
I'll go through the manual and check it out - I was just hoping someone would see my post and say"Hey, that's what happened to me and it was the 'Purgolator' ", or something -
S'Nut
I'll go through the manual and check it out - I was just hoping someone would see my post and say"Hey, that's what happened to me and it was the 'Purgolator' ", or something -
S'Nut
Thread Starter
Burning Brakes
Joined: Dec 2002
Posts: 1,199
Likes: 4
From: Cairns Australia
I'm having trouble locating the info on the MAF in the Factory manuals - can anyone point me in the right direction ?
It seems that although each year manual is different, the section numbers ie 6 Engine 5 Brakes, stay the same.
I've cleaned and tightened the plastic boot between the TB and the MAF, in case there was an air leak - I'm still throwing the code occasionally.
I noticed that I don't hear the MAF burn off anymore, so I replaced both relays - still don't hear anything (am I going deaf - damm that 500watt stereo)
S'nut
It seems that although each year manual is different, the section numbers ie 6 Engine 5 Brakes, stay the same.
I've cleaned and tightened the plastic boot between the TB and the MAF, in case there was an air leak - I'm still throwing the code occasionally.
I noticed that I don't hear the MAF burn off anymore, so I replaced both relays - still don't hear anything (am I going deaf - damm that 500watt stereo)
S'nut
Drifting
Joined: Aug 2004
Posts: 1,400
Likes: 0
From: Oceansaide CA
Originally Posted by Stingraynut
I'm having trouble locating the info on the MAF in the Factory manuals - can anyone point me in the right direction ?
S'nut
S'nut
In all seriousness, I'm having the same problem. Mine threw a burn-off circuit code, and hasn't run right since. if you get it figured out, PM me or something, and I'll do the same. I'm starting to think it's my ECM, so I'm gonna go and buy a new one from NAPA. If it doesn't work, I'll return it and keep on throwing parts and checking wires untill something happens.
So far replaced both relays, and it helped but didn't fix it. Hesitates like no other and likes to die.
What does burn off sound like?
Melting Slicks
Joined: May 2001
Posts: 3,270
Likes: 26
From: Winchester VA
Cruise-In V Veteran
Is it a 4+3 car? To "nut", I see clarence is a 6sp.
There is a connector under the wiper motor, 5 pin flat ~2in wide, that when corroded, will affect the overdrive and MAF, specifically the burn off circuit.
My maf went dead, code 34 popped up, "overdrive engaged light on" and had to keep the car above 3500rpm to keep it running on the way to work one morning.
This is from an 85, probably close enough to 88 to be similar.
There is a connector under the wiper motor, 5 pin flat ~2in wide, that when corroded, will affect the overdrive and MAF, specifically the burn off circuit.
My maf went dead, code 34 popped up, "overdrive engaged light on" and had to keep the car above 3500rpm to keep it running on the way to work one morning.
This is from an 85, probably close enough to 88 to be similar.
Last edited by Steve85; Dec 14, 2004 at 11:17 PM.
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Thread Starter
Burning Brakes
Joined: Dec 2002
Posts: 1,199
Likes: 4
From: Cairns Australia
"Certainly, it's the black thing between your throttle body and the air filter "
Ha HA - I know where the MAf is, but where is the info in the Service manual.
What is the number for a burn off circuit code ?
Unfortunately my ALDL won't communicate with a laptop, it's been like that for 2 years or more - it might help to get more fugures.
I plan to fix that when the temps go down,after Easter. It's way too hot here at the moment.
The burn off sound is hard to remember, I don't think I've heard it for a while, but I think it's a slight buzzing or hissing for a few seconds immediately after turning off the engine. I remember I used to hear it and I read here on the forum what it was.
I wished I lived somewhere I could pop down the road and buy a new ECM !! Currently I think it could be a poor connection 'somewhere', an ECM slowly going faulty or a MAF wearing out or whatever they do.
It only throws the code occasionally and the car runs fine, fuel economy v good.
Just another character building 'vette mystery'
S'nut
Ha HA - I know where the MAf is, but where is the info in the Service manual.
What is the number for a burn off circuit code ?
Unfortunately my ALDL won't communicate with a laptop, it's been like that for 2 years or more - it might help to get more fugures.
I plan to fix that when the temps go down,after Easter. It's way too hot here at the moment.
The burn off sound is hard to remember, I don't think I've heard it for a while, but I think it's a slight buzzing or hissing for a few seconds immediately after turning off the engine. I remember I used to hear it and I read here on the forum what it was.
I wished I lived somewhere I could pop down the road and buy a new ECM !! Currently I think it could be a poor connection 'somewhere', an ECM slowly going faulty or a MAF wearing out or whatever they do.
It only throws the code occasionally and the car runs fine, fuel economy v good.
Just another character building 'vette mystery'
S'nut
Melting Slicks
Joined: May 2001
Posts: 3,270
Likes: 26
From: Winchester VA
Cruise-In V Veteran
Originally Posted by Stingraynut
RainDelay - my 1988 is an auto, does it make a difference to the MAF ?
S'nut
S'nut
Not sure about an auto as it relates to that connector and the code 34. I'll see what I can find....
Thread Starter
Burning Brakes
Joined: Dec 2002
Posts: 1,199
Likes: 4
From: Cairns Australia
Thanks RainDelay, as my symptom is MAF code and no freewheel in Overdrive it sounds as if that is a likely part to check.
I ran out of time today, will have a look tomorrow and post back.
S'nut
I ran out of time today, will have a look tomorrow and post back.
S'nut
Team Owner
Joined: Jan 2003
Posts: 20,332
Likes: 262
From: Summerland B.C. Canada
Racer
Joined: Jul 2004
Posts: 434
Likes: 0
From: Santa Barbara Minnesota
Sounds very similar to my code 33 ..
Originally Posted by Stingraynut
My 88 vette has thrown code 34 a few times in the last 6 weeks.
That is supposed to point to the MAF - relays or Maf itself but the the engine runs fine, no problems, fuel economy normal. The relays were replaced 18 months ago.
So I don't think it has anything to do with the MAF
The code comes back ONLY when I start the engine too quickly. Once the engine is warm it goes away on a restart.
There is only one symptom when the SES light is on -the overdrive is different - when I back off the throttle the gears don't freewheel like they usually do. Definitely very different to when the SES light is off.
When I wait 10 seconds after turning the ignition on, I hear a creaking from behind the dash - must be an aircon or heater door moving. Once I hear that noise I start the engine and no SES light.
Any ideas ?
S'Nut
That is supposed to point to the MAF - relays or Maf itself but the the engine runs fine, no problems, fuel economy normal. The relays were replaced 18 months ago.
So I don't think it has anything to do with the MAF
The code comes back ONLY when I start the engine too quickly. Once the engine is warm it goes away on a restart.
There is only one symptom when the SES light is on -the overdrive is different - when I back off the throttle the gears don't freewheel like they usually do. Definitely very different to when the SES light is off.
When I wait 10 seconds after turning the ignition on, I hear a creaking from behind the dash - must be an aircon or heater door moving. Once I hear that noise I start the engine and no SES light.
Any ideas ?
S'Nut
The only solution was a custom chip, we took out code33 & a few others. In fact I'm going back on the dyno this afternoon to recalibrate one little thing in relation to this problem, resetting gpm. higher. Code 33 & 34 relate to the same system. LOL.
Thread Starter
Burning Brakes
Joined: Dec 2002
Posts: 1,199
Likes: 4
From: Cairns Australia
Thanks Agent 86, I can never find anything in the workshop manual - I saw 6E3 - A52 at the top of the PDF file and then found the corresponding page in my manual which is 6E3 - A 44. (I've now marked the index 'Codes')
I note that low airflow can trigger the code, I wonder if I need a new air filter ?
#70SM2 - I hate to hear stories like that. Your solution was very radical - I've heard another solution is to pull the SES bulb out !!
I've put new relays in, drove around yesterday with 4 re-starts and so far no codes thrown. I've got my fingers crossed, but I'm still not hearing the burn off when I turn the ignition off.
#70SM2 - how much do you want for one of your MAF's ? My email is make_contact_@hotmail.com
RainDelay -I'm having trouble finding that connector under the wiper motor - my car is converted to Right Hand Drive and everything is moved - the master brake cyclinder is on the Right and Aircon on the left !!
S'nut
I note that low airflow can trigger the code, I wonder if I need a new air filter ?
#70SM2 - I hate to hear stories like that. Your solution was very radical - I've heard another solution is to pull the SES bulb out !!
I've put new relays in, drove around yesterday with 4 re-starts and so far no codes thrown. I've got my fingers crossed, but I'm still not hearing the burn off when I turn the ignition off.
#70SM2 - how much do you want for one of your MAF's ? My email is make_contact_@hotmail.com
RainDelay -I'm having trouble finding that connector under the wiper motor - my car is converted to Right Hand Drive and everything is moved - the master brake cyclinder is on the Right and Aircon on the left !!
S'nut
Melting Slicks
Joined: May 2001
Posts: 3,270
Likes: 26
From: Winchester VA
Cruise-In V Veteran
i can't find anything, for real, we recently moved and my manual is mia. i have been relying on my alldata subscription but it is for 85 only. i don't think you will have it though, as it ties in with the od unit of a 4+3.
for rh drive, try under master cylinder
for rh drive, try under master cylinder
Racer
Joined: Jul 2004
Posts: 434
Likes: 0
From: Santa Barbara Minnesota
Originally Posted by Stingraynut
Thanks Agent 86, I can never find anything in the workshop manual - I saw 6E3 - A52 at the top of the PDF file and then found the corresponding page in my manual which is 6E3 - A 44. (I've now marked the index 'Codes')
I note that low airflow can trigger the code, I wonder if I need a new air filter ?
#70SM2 - I hate to hear stories like that. Your solution was very radical - I've heard another solution is to pull the SES bulb out !!
I've put new relays in, drove around yesterday with 4 re-starts and so far no codes thrown. I've got my fingers crossed, but I'm still not hearing the burn off when I turn the ignition off.
#70SM2 - how much do you want for one of your MAF's ? My email is make_contact_@hotmail.com
RainDelay -I'm having trouble finding that connector under the wiper motor - my car is converted to Right Hand Drive and everything is moved - the master brake cyclinder is on the Right and Aircon on the left !!
S'nut
I note that low airflow can trigger the code, I wonder if I need a new air filter ?
#70SM2 - I hate to hear stories like that. Your solution was very radical - I've heard another solution is to pull the SES bulb out !!
I've put new relays in, drove around yesterday with 4 re-starts and so far no codes thrown. I've got my fingers crossed, but I'm still not hearing the burn off when I turn the ignition off.
#70SM2 - how much do you want for one of your MAF's ? My email is make_contact_@hotmail.com
RainDelay -I'm having trouble finding that connector under the wiper motor - my car is converted to Right Hand Drive and everything is moved - the master brake cyclinder is on the Right and Aircon on the left !!
S'nut
I need to keep my 2 stock maf's as I run without screens, good to have a backup. The 3d. is a Granatelli race maf. but I don't think you would like that one, it doesn't use a burnoff. It has a credit card like circuit board standing vertically in it. My motor won't run cold with it, maybe it doesn't like my chip. It only has a couple starts on it. It did run ok before the new built motor. Let me know if your interested in it. Programming the codes out is awesome, it worked, the only other alternative I knew of is to rewire a complete new harness and replace every part. Now if I can just get my hair to grow back!
Racer
Joined: Jul 2004
Posts: 434
Likes: 0
From: Santa Barbara Minnesota
Code 33 & 34
Originally Posted by #70SM2
Well I'll tell ya, code33 drove absolutely Nuts' .. I've had it beginning 2001. It would set check engine at 2000rpm. or if I drove before complete warmup. I used to have a full head of hair before code33. We finally finished today, 4 years later! Larry at Camarrillo Performance made another chip w/airflow parameters set higher. he uses a Mustang Dyno and is a great guy, serious drag racer, runs 8's with an old chevelle.
I need to keep my 2 stock maf's as I run without screens, good to have a backup. The 3d. is a Granatelli race maf. but I don't think you would like that one, it doesn't use a burnoff. It has a credit card like circuit board standing vertically in it. My motor won't run cold with it, maybe it doesn't like my chip. It only has a couple starts on it. It did run ok before the new built motor. Let me know if your interested in it. Programming the codes out is awesome, it worked, the only other alternative I knew of is to rewire a complete new harness and replace every part. Now if I can just get my hair to grow back!
I need to keep my 2 stock maf's as I run without screens, good to have a backup. The 3d. is a Granatelli race maf. but I don't think you would like that one, it doesn't use a burnoff. It has a credit card like circuit board standing vertically in it. My motor won't run cold with it, maybe it doesn't like my chip. It only has a couple starts on it. It did run ok before the new built motor. Let me know if your interested in it. Programming the codes out is awesome, it worked, the only other alternative I knew of is to rewire a complete new harness and replace every part. Now if I can just get my hair to grow back!
This post is relevant to your code33 problem, so I'm reviving it. Like I said, this drove me completely nuts. It was solved only by reprogramming the prom .. maybe radical solution, But it Worked!
Thread Starter
Burning Brakes
Joined: Dec 2002
Posts: 1,199
Likes: 4
From: Cairns Australia
Problem SOLVED (I think)
Looks like I've fixed the problem - I replced the two relays and have had no codes in a week.
I had this problem when I bought the car 18 months ago and fitted new relays - I doubt that a relay dies in such a short time so I suspect that somewhere the wiring or connections are altering the data going to the ECM.
Lucky I had just ordered 2 spare relays - now I'd better order some more.
Thanks for all the help.
S'mut
I had this problem when I bought the car 18 months ago and fitted new relays - I doubt that a relay dies in such a short time so I suspect that somewhere the wiring or connections are altering the data going to the ECM.
Lucky I had just ordered 2 spare relays - now I'd better order some more.
Thanks for all the help.
S'mut
Racer
Joined: Jul 2004
Posts: 434
Likes: 0
From: Santa Barbara Minnesota
Originally Posted by Stingraynut
Looks like I've fixed the problem - I replced the two relays and have had no codes in a week.
I had this problem when I bought the car 18 months ago and fitted new relays - I doubt that a relay dies in such a short time so I suspect that somewhere the wiring or connections are altering the data going to the ECM.
Lucky I had just ordered 2 spare relays - now I'd better order some more.
Thanks for all the help.
S'mut
I had this problem when I bought the car 18 months ago and fitted new relays - I doubt that a relay dies in such a short time so I suspect that somewhere the wiring or connections are altering the data going to the ECM.
Lucky I had just ordered 2 spare relays - now I'd better order some more.
Thanks for all the help.
S'mut
