1987 C4 wont start, Code 34?
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Joined: Sep 2022
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From: Southern California
1987 C4 wont start, Code 34?
Had some idle issues where it would rev without me doing anything so replaced the IAC valve and it dropped the rpm to 600 and kept it there. But sometimes would dwindle out and then just die. It gave me a code 34 so i cleaned my MAF and made sue it was plugged in. Now it wont turn on at all and still giving me a code 34 while making this noise. I need some help guys 🥲.
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Joined: Sep 2022
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From: Southern California
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Melting Slicks
Joined: Aug 2003
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From: Lakeville MI
Code 33 is from running it with the MAF unplugged. The maf signal is pulled up to 5 volts by the ecm when the MAF is disconnected so that an open circuit can be detected.
Code 34 (maf low) could be a short to ground, a malfunctioning sensor (or relays) or significant air bypassing the sensor.
Code 34 (maf low) could be a short to ground, a malfunctioning sensor (or relays) or significant air bypassing the sensor.
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Joined: Sep 2022
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From: Southern California
Problem solved?
I used some contact cleaner for the connections on the maf and no codes have shown up thus far, I'm idling at 7-8 rpm. it idles high at first for like 4-5 seconds at 10-12, but then quickly goes down like its getting accustomed and settled if anything more occurs ill be sure to report back, but I appreciate all the help, the people on these forums are life savers.
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Joined: Sep 2022
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Update
The engine idled fine but when it got up to temp and i turned it off it wouldnt turn back on the engine would crank and fire but would not idle. Ive heard this is a common issue with C4’s?. I noticed the bolt that screws into the battery terminal was messed up slightly and would loosen after it tightens, could this be my culprit?
If i give it gas while turning the ignition it starts right up but without my foot it will quickly die out, im not getting any engine codes at all.
If i give it gas while turning the ignition it starts right up but without my foot it will quickly die out, im not getting any engine codes at all.