C4 Tech/Performance L98 Corvette and LT1 Corvette Technical Info, Internal Engine, External Engine

Code 33 and 34 MAF 1986 convert

 
Old 03-12-2019, 07:49 PM
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Ffranzwa
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Default Code 33 and 34 MAF 1986 convert

Hi everyone. I have a persistent code 33+34 going back to 1995 when I bought an '86 convertible with 83k. Back in 1997, I replaced the MAF sensor, but the codes persisted. I was mad, especially since the MAF was a pricey sensor, so I learned to live with it. Fast forward to last fall, the intake gasket failed and was leaking coolant into the crankcase, so I did a top end on it. I replaced everything that was a wear part, including vac lines. I was excited to finally drive the car without a SES light, but no luck. So I'm reaching out to ask advice on where to go from here. I can order a new MAF sensor for about $70, which is a lot cheaper than what I paid for the last replacement, but I'm afraid the light will remain. Is there a relay, or something I'm missing? Chiltons says to check terminal C to test for voltage. Which one of the 4 wires is "C"? Any help will be appreciated!
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Old 03-12-2019, 11:29 PM
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Kevova
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You really need factory manuals, more details and component locator. There are 2 relays MAF power and burn off. It is recommended to replace relays before replacing MAF.
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Old 03-13-2019, 01:13 AM
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net_coma
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Similar issue with a tpi IROC. Tried 2 MAF sensors, driveabiliry was in the tank. Member on third gen.org provided a very short reply, check the tps. That cured my problem. I donít have the Camaro but still have the mass air flow sensors + one for the corvette.
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Old 03-13-2019, 07:11 AM
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You can edit the limits for the code(s) in the chip using TunerPro or TunerCat. However your VERY BEST route is to buy my slot style MAF which eliminates all the bullshit ! lol BlowerWorks.net
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Old 03-13-2019, 08:23 AM
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KyleF
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Originally Posted by Ffranzwa View Post
Hi everyone. I have a persistent code 33+34 going back to 1995 when I bought an '86 convertible with 83k. Back in 1997, I replaced the MAF sensor, but the codes persisted. I was mad, especially since the MAF was a pricey sensor, so I learned to live with it. Fast forward to last fall, the intake gasket failed and was leaking coolant into the crankcase, so I did a top end on it. I replaced everything that was a wear part, including vac lines. I was excited to finally drive the car without a SES light, but no luck. So I'm reaching out to ask advice on where to go from here. I can order a new MAF sensor for about $70, which is a lot cheaper than what I paid for the last replacement, but I'm afraid the light will remain. Is there a relay, or something I'm missing? Chiltons says to check terminal C to test for voltage. Which one of the 4 wires is "C"? Any help will be appreciated!
You need to make sure you get a old style heated wire type MAF or you will live with codes.

There is a lot going on, besides just replacing parts have you done any trouble shooting? IMO is is strange to see both 33/34 together. I would suspect a Faulty MAF or most likely issues with 30 year old wiring.
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Old 03-13-2019, 08:36 AM
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vader86
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First thing you should always do with a MAF is replace the relays, they are on the firewall behind the battery. There are 2. If one fails, replace both. If the MAF itself fails, replace both with it.

See if the SES comes back before you replace a MAF sensor
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Old 03-13-2019, 12:22 PM
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Old 03-13-2019, 12:45 PM
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Disagree !!! See my website ! greg
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Old 03-13-2019, 02:26 PM
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KyleF
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Originally Posted by vader86 View Post
First thing you should always do with a MAF is replace the relays, they are on the firewall behind the battery. There are 2. If one fails, replace both. If the MAF itself fails, replace both with it.

See if the SES comes back before you replace a MAF sensor
First thing you should do is troubleshoot. Don't just throw parts or re-engineered parts at a problem. You may never get it fixed and be out money.
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Old 03-13-2019, 02:29 PM
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Originally Posted by KyleF View Post
First thing you should do is troubleshoot. Don't just throw parts or re-engineered parts at a problem. You may never get it fixed and be out money.
Troubleshooting is a given.

If the troubleshooting points to the relay, replace both relays.

if the troubleshooting points to the MAF, repalce both relays, wait for the code to come back, and then the MAF.

EIther way, you should replace the relays.

Last edited by vader86; 03-13-2019 at 02:33 PM.
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Old 03-13-2019, 02:56 PM
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3D-Aircrew
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Originally Posted by vader86 View Post
Troubleshooting is a given.

If the troubleshooting points to the relay, replace both relays.

if the troubleshooting points to the MAF, repalce both relays, wait for the code to come back, and then the MAF.

EIther way, you should replace the relays.

Also sometimes the new relays are DOA. I went through a few to get rid of my MAF codes. (1986 vert)

Last edited by 3D-Aircrew; 03-13-2019 at 03:01 PM.
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Old 03-14-2019, 08:12 AM
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KyleF
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Originally Posted by vader86 View Post
Troubleshooting is a given.
No it's not, most threads start with "I replaced...." Because trouble shooting stopped with pulling a code and replacing whatever components that code referred to.

Originally Posted by vader86 View Post
First thing you should always do with a MAF is replace the relays
Your own words man... specifying "First Thing"

First thing is consult a FSM, Google, or here to get the code troubleshooting flow chart and follow it.
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Old 03-14-2019, 08:22 AM
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vader86
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Whatever you say dude, whatever makes you feel better.

Experience has taught me, that whatever it is with the MAF, you replace the relays either way.
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Old 03-14-2019, 12:27 PM
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KyleF
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Originally Posted by vader86 View Post
Whatever you say dude, whatever makes you feel better.

Experience has taught me, that whatever it is with the MAF, you replace the relays either way.
Then comes the thread... "I have replaced my relays and my MAF... still have issues. Why?"

Start trouble shooting before throwing parts at it. Unless you just don't care about Money.
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