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Hello all,
1987 Corvette coupe black / red 59000 miles auto. As I put my Corvette away last November for the Winter I got a check engine light. The car hesitated a bit but ran pretty well. I put it away until today. Drove it home with the check engine light on. Ran fairly well. Got home and checked the codes. Got a 33,34,36. Unplugged the battery and the MAF sensor for 15 minutes or so. Plugged the MAF back in and connected the battery. Check engine light came on again only this time only the code 33 (map sensor signal out of range-High). Same code came on each time I drove it today. Is this MAF sensor related, or relay related? The sensor is only maybe 3 years old. Would a cleaning help?
87 is MAF only. No MAP sensor. It is very UN-likely a 3 Y/O MAF is bad. Did you purchase a reman??
Look at the filament for any build up. You could use carb clearner to spray off any build up.
You should also check your MAF relay switches. Especially the burn off relay.
Last edited by THE 383 admiral; Apr 2, 2017 at 11:21 PM.
At night or in a dark garage...
Pull your air hose from the filter end and set it up so you can look down into the maf sensor. Start the car and have someone turn it off while you are looking down into the maf sensor. If you see the burn off wire light up your relay(and circuit) is good. You should also hear the relay "click" when it heats up the wire. If you get nothing you can try swapping relays.
Thank you everyone for the replies...Both relays were changed at the same time as the MAF . Swapped out with GM replacements. The MAF was new but not sure of the manufacturer. I will check the suggestions mentioned.
Thanks again,
Code 36 fixed-Watch where you run your MAF harness
Swapped out my two MAF relays and cleaned the MAF with MAF cleaner. Also cleaned the connector. Still a code 36 although the car ran much better with not too much of a rich smell. Today I was looking at the MAF harness and saw that it was close to a pulley. Closer inspection it was at the pulley which had eaten away my black wire and was getting at the green and purple one. I re-spliced the wires and routed it safely out of the way. No more code 36. Hope this helps someone else. Thanks to all of the replies.
On my 85 C4 (sold but not forgotten) I hunted intermittent code 33 & code 34 in my 85 C4 for over about 2 years. After swapping the engine and tranny, cleaning every single connector and ground, buying/trading MULTIPLE MAF sensors from every auto parts store in town, eventually I bought an original Bosch new-old-stock MAF... that made it disappear till one day it came back. I went through 2 burn off modules (1 rebuilt) then finally cracked the burn off module open, looked through my Hanes wiring diagram, and after about 30 minutes of testing wires with a multimeter, then splicing a resistor in between a crappy module in the module.... NO MORE CODE 33 OR 34. I lost sleep over those codes and still twitch at the sight of those numbers.
Code 33
I re-spliced the wires and routed it safely out of the way. No more code 36. 
Hope this helps someone else. Thanks to all of the replies.
