andrewtjahn

hello, yesterday 6/8/15 i purchased my very first covette. 1989 c4. anyways so 1 mile down the road and i bought it off the lot the check engine light comes on. car is still running good when i get home. so as soon as i get home i see what the light says. gives me code 12, 34, and 36. i have an 87 iroc that has bad rod knock. but after i see my codes i disconnect the battery and switch the mass air flow sensors. i go to start the car and it wont fully turn over just tries like im missing gas or spark. i put the old sensor back in and the car wont start, now im getting worried cause it use to start with the old sen. anyways later that evening i go to az a get a new mass air flow sensor. car still wont start. it use to till i touched it. did some happen when i disconnected the battery? like anti theft or something along those lines? im not really sure. i havent even drivin this car 2 miles yet. im about to call up the dealer and tell him to fix it but im not sure if its my fault its not running.

don hall

Welcome to the Corvette community.

This link may help in determining the problem and the remedy. There are several pages, so read them all:

http://www.corvettephotographs.com/c4vettes/ecm.htm

andrewtjahn

thanks for the fast reply. i read it all and saw my codes. i get off work in 3 hours. ill inspect the connector and throw some dielectric grease in there.

vader86

Follow the procedures here
http://members.shaw.ca/corvette86/Code%2034.pdf

http://members.shaw.ca/corvette86/Code%2036.pdf

There may be minor differences that I'm not aware of for 89, but the procedure is the same.

Test the burnoff circuit first. There are two relays behind the battery on the firewall, if one is bad, replace both. If the MAF itself is bad, replace all 3.

playsdixie

welcome to the forum!! can't give any better advice that what you've already gotten...except that for sure you'll be needing a GM manual...ebay is the cheapest....

Cliff Harris

Error code 36 is a MAF burnoff fault. That test is done AFTER the ignition is turned off.

Based on the error code 34, I would say you have a bad connection between the MAF and the ECM. Corroded connector pins are your most likely culprit.