1987 Code 36
Thread Starter
Instructor
Joined: Apr 2005
Posts: 128
Likes: 0
1987 Code 36
Service Engine light it on all the time now.
I keep getting code 36 setting for the mass air burnoff.
I also sets 33 and 34
I am using a Snap On SOLUS scanner .
After clearing the codes only 36 resets
As part of testing I checked the voltages to the relays and they worked fine.
I changed the relays.
I checked the MAF voltage to the plug and it was OK.
I changed the MAF anyway .
Code still sets.
When i clear the codes with the scanner it resets imediattly.
the scanner burnoff test shows OFF
Once of twice i seen ON for a second like it worked
But it went right back to OFF and set the code 36 again.
Could the ECM board be bad?
Could it not register that the burnoff is working?
It goes into Limp Home Mode and runs rich and burns tons of fuel.
there are other problems that are clsely related but may not be part of the problem. I had rough running and overheating at one time because the fan did not work. The relay plug burned like many have and was replaced. I fixd that and worked for a while until it overheated again.
This time I found the original ECM chip was bad and replaced it with a hypertech aftermarket chip. The fan works now. But I have a feeling it may be in the ECM itself. It has always had intermittent problems.
I need to solve the problem because it is running super rich when the code 36 sets because it goes into Limp Home Mode. There is no switching from closed loop to open loop at all.
The scanner shows the O2 sensor is eratic and It goes to 0 sometimes when throttling on and off and up to 500+ . It most likely needs replacing. The scanner shows it going from a lean to rich condition every few seconds and when I throttle up and down.
Other problems are my cruise is not working and neither is the heater fan motor and AC fan. My security system is not working properly because of possible a few bad wires in the door. I remember reading that these are connected through the dash and gauges but not sure if this can affect the ECM or circuit. I once had the flickering gauge problem a decade ago under waranttee and they replaced the gauges. The anti lock light is on but that runs on a seperate circuit.
The service engine light is makeing it run in limp home mode. When the problem first started years ago I could shut the car off and restart it and the light would go off and run great. Then i would be able to drive it until I would restart it. Sometimes it would go on and mostly if didn't. Now that trick no longer works.
Car is balanced and blueprinted with 10.75 to 1 compression and a 528 cam and poerted heads and a ton of other work. When I kick it down black smoke. Always ran hgreat until this dilema. Runs super rich and burns fuel like crazy.
I am wondering if the ECM could be faulty?
Has anyone seen this happen before?
Are there any checks I can do on the ECM or should I just replace it.
I got a lot of good spare parts from replacing things already.
I keep getting code 36 setting for the mass air burnoff.
I also sets 33 and 34
I am using a Snap On SOLUS scanner .
After clearing the codes only 36 resets
As part of testing I checked the voltages to the relays and they worked fine.
I changed the relays.
I checked the MAF voltage to the plug and it was OK.
I changed the MAF anyway .
Code still sets.
When i clear the codes with the scanner it resets imediattly.
the scanner burnoff test shows OFF
Once of twice i seen ON for a second like it worked
But it went right back to OFF and set the code 36 again.
Could the ECM board be bad?
Could it not register that the burnoff is working?
It goes into Limp Home Mode and runs rich and burns tons of fuel.
there are other problems that are clsely related but may not be part of the problem. I had rough running and overheating at one time because the fan did not work. The relay plug burned like many have and was replaced. I fixd that and worked for a while until it overheated again.
This time I found the original ECM chip was bad and replaced it with a hypertech aftermarket chip. The fan works now. But I have a feeling it may be in the ECM itself. It has always had intermittent problems.
I need to solve the problem because it is running super rich when the code 36 sets because it goes into Limp Home Mode. There is no switching from closed loop to open loop at all.
The scanner shows the O2 sensor is eratic and It goes to 0 sometimes when throttling on and off and up to 500+ . It most likely needs replacing. The scanner shows it going from a lean to rich condition every few seconds and when I throttle up and down.
Other problems are my cruise is not working and neither is the heater fan motor and AC fan. My security system is not working properly because of possible a few bad wires in the door. I remember reading that these are connected through the dash and gauges but not sure if this can affect the ECM or circuit. I once had the flickering gauge problem a decade ago under waranttee and they replaced the gauges. The anti lock light is on but that runs on a seperate circuit.
The service engine light is makeing it run in limp home mode. When the problem first started years ago I could shut the car off and restart it and the light would go off and run great. Then i would be able to drive it until I would restart it. Sometimes it would go on and mostly if didn't. Now that trick no longer works.
Car is balanced and blueprinted with 10.75 to 1 compression and a 528 cam and poerted heads and a ton of other work. When I kick it down black smoke. Always ran hgreat until this dilema. Runs super rich and burns fuel like crazy.
I am wondering if the ECM could be faulty?
Has anyone seen this happen before?
Are there any checks I can do on the ECM or should I just replace it.
I got a lot of good spare parts from replacing things already.
Team Owner
Joined: Aug 2000
Posts: 40,156
Likes: 45
From: San Pedro CA
Check the entire harness. Early C4s have junk wire that is prone to chaffing and failure.
Check the relays, they should be replaced with the MAF.
And don't just throw good money after bad with these cars... they will nickle and dime you to death, otherwise.
Check the relays, they should be replaced with the MAF.
And don't just throw good money after bad with these cars... they will nickle and dime you to death, otherwise.
Melting Slicks
Joined: Jul 2004
Posts: 2,018
Likes: 1
From: OR
Service Bulletin Number: 87-99
Bulletin Sequence Number: 050
Date of Bulletin: 8704
NHTSA Item Number: 90918
Make: CHEVROLET
Model: CORVETTE
Year: 1987
Component: FUEL:FUEL EMISSION CONTROL
Summary: SERVICE ENGINE SOON LIGHT-CODE 36 (MAF SENSOR BURN-OFF FAULT)-PUGGED CRANKCASE V ENT TUBE OR FAULTY MAF POWER OR BURN OFF RELAYS-TEST RELAY-REPLACE THE RELAY-ALL 1986-87 CHEVROLET CAMARO/CORVETTE MODELS WITH PFI ENGINES (VIN CODES F AND 8)
When mine threw a code 36, the check engine light was on but I don't think it was in limp mode. Didn't mis a beat and didn't register any decrease in fuel economy. Being too lazy to do all that testing you did, I just replaced the relays. That fixed mine. Good luck.
Bulletin Sequence Number: 050
Date of Bulletin: 8704
NHTSA Item Number: 90918
Make: CHEVROLET
Model: CORVETTE
Year: 1987
Component: FUEL:FUEL EMISSION CONTROL
Summary: SERVICE ENGINE SOON LIGHT-CODE 36 (MAF SENSOR BURN-OFF FAULT)-PUGGED CRANKCASE V ENT TUBE OR FAULTY MAF POWER OR BURN OFF RELAYS-TEST RELAY-REPLACE THE RELAY-ALL 1986-87 CHEVROLET CAMARO/CORVETTE MODELS WITH PFI ENGINES (VIN CODES F AND 8)
When mine threw a code 36, the check engine light was on but I don't think it was in limp mode. Didn't mis a beat and didn't register any decrease in fuel economy. Being too lazy to do all that testing you did, I just replaced the relays. That fixed mine. Good luck.
Thread Starter
Instructor
Joined: Apr 2005
Posts: 128
Likes: 0
don't just throw good money after bad with these cars
they sure will !!!
-------------------------
I did replace both the relays!
I replaced the MAF to.
Now I have a good set of spares because they were fine.
-------------------------
It is one of those weird problems I have like my ABS brake system problem and my dragging brake problem.
I think i finally solved that one.
--------------------------
Any help from anyone that had this code 36 problem let me know
I tried and tested everything I think.
Now it is getting worse and my clothes smell from the rich fuel mixture.
When i kick it down it dumps fuel.
Still flies but way to much fuel.
That is not good for the rings.
Only thing I didn't replace was the ECM.
they sure will !!!
-------------------------
I did replace both the relays!
I replaced the MAF to.
Now I have a good set of spares because they were fine.
-------------------------
It is one of those weird problems I have like my ABS brake system problem and my dragging brake problem.
I think i finally solved that one.
--------------------------
Any help from anyone that had this code 36 problem let me know
I tried and tested everything I think.
Now it is getting worse and my clothes smell from the rich fuel mixture.
When i kick it down it dumps fuel.
Still flies but way to much fuel.
That is not good for the rings.
Only thing I didn't replace was the ECM.
Team Owner
Joined: Jan 2003
Posts: 20,254
Likes: 221
From: Summerland B.C. Canada
Are using the factory manual to diagnose you 33 and others ??
http://members.shaw.ca/corvette86/Code%2036.pdf
http://members.shaw.ca/dankai/AC%20Electronic.pdf
http://members.shaw.ca/dankai/Air%20...0%20Manual.pdf
http://members.shaw.ca/agent86/Cruise%20Control.pdf
http://members.shaw.ca/agent86/Vats%20Electrical.pdf
http://members.shaw.ca/agent86/ABS%20Electrical.pdf
http://members.shaw.ca/agent86/ABS.pdf
http://members.shaw.ca/corvette86/Code%2036.pdf
http://members.shaw.ca/dankai/AC%20Electronic.pdf
http://members.shaw.ca/dankai/Air%20...0%20Manual.pdf
http://members.shaw.ca/agent86/Cruise%20Control.pdf
http://members.shaw.ca/agent86/Vats%20Electrical.pdf
http://members.shaw.ca/agent86/ABS%20Electrical.pdf
http://members.shaw.ca/agent86/ABS.pdf
Team Owner
Joined: Jan 2003
Posts: 20,254
Likes: 221
From: Summerland B.C. Canada
Le Mans Master
Joined: Oct 2003
Posts: 6,130
Likes: 2
From: seattle WA
Sounds like you have a ton of problems...some may be related..others are not! And you've already replaced most of the components that can cause a 36 to be set......provided you checked all connections to make sure they're clean and tight. The last component on the TS tree is the ECM...some time ago I posted something to the affect "what were your symptoms when the ECM went bad?". The majority of those that responded stated their cars "ran pig rich". I'd be checking the connections at the ECM first...problem is, I don't know anyone that has the ability to check whether an ECM is good or bad. Alot of good information posted...you'll have to make the call on the ECM.
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Pro
Joined: Sep 2006
Posts: 702
Likes: 2
From: Conyers Ga
Regarding the cruise control I'd check the fuse first then check for a vacuum leak. When you say the heater fan doesn't come on do you mean it won't "energize" or you can't feel air blowing through the ducts? That too could be vacuum related. Check all your lines for cracks.
