'87 code 33.
Thread Starter
Drifting
Joined: Dec 2006
Posts: 1,771
Likes: 1
From: Cuyahoga Falls Ohio
'87 code 33.
Coming to work this morning, my car almost completely stalled out on me. I was coming up a hill, and it hesitated, then bogged, big time, no power. I let off the gas, pushed it to overdrive, it stumbled, but picked up and got me to the top. I put it in drive and got to work, about 2 more miles.
I went home for lunch, and it ran very well. Go figure. I pulled the codes by jumpering pins A and B. I got a 33. That translates to MAF, vaccuum lines, or bad ecm.
Ever since the weather got a little better, this car hasn't run quite right. It runs great when it's cold outside. It also runs pretty good once the car warms up, all the way. But I've noticed it idles rough when started, and will hesitate or bog down on acceleration, sometimes.
I'll do a visual inspection of hoses tonight, but what else can I check myself?
I went home for lunch, and it ran very well. Go figure. I pulled the codes by jumpering pins A and B. I got a 33. That translates to MAF, vaccuum lines, or bad ecm.
Ever since the weather got a little better, this car hasn't run quite right. It runs great when it's cold outside. It also runs pretty good once the car warms up, all the way. But I've noticed it idles rough when started, and will hesitate or bog down on acceleration, sometimes.
I'll do a visual inspection of hoses tonight, but what else can I check myself?
Team Owner
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From: Athens AL
C7 of the Year - Unmodified Finalist 2021
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Thread Starter
Drifting
Joined: Dec 2006
Posts: 1,771
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From: Cuyahoga Falls Ohio
Thread Starter
Drifting
Joined: Dec 2006
Posts: 1,771
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From: Cuyahoga Falls Ohio
Doesn't the IAC have something to do with this too? Just one relay on the 87 to swap out?
Thread Starter
Drifting
Joined: Dec 2006
Posts: 1,771
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From: Cuyahoga Falls Ohio
Le Mans Master
Joined: Aug 2003
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From: Magnolia Mississippi
St. Jude '03-'04-'05-'06-'07
sometimes it does, you can also swap the relays and see if that code goes away, then get new relays, about $20 each at NAPA, and both are the same part no
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Thread Starter
Drifting
Joined: Dec 2006
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From: Cuyahoga Falls Ohio
Where are these relays located? I went and checked out the MAF, and the connector wires run into a plastic conduit, and from there I can't tell where the relay is. I want the power relay, not the burn off relay, right?
Ok, I found the relays, they are behind the battery. Which one is power, which is burn off? They're the same? Is it reasonable to just shotgun and swap both?
I went out and checked the two of them out. I can't tell which is which, but it looks like there's enough slack to swap connectors on the 2 relays. That is, IF I could figure out how to unplug them. Do I have to unscrew the bracket holding the 2 relays so I can get a good grip and pull the connectors out? Or, how do I get them out? I'll give GM credit, they're definately securely fastened.
Last edited by DaleD; Apr 19, 2007 at 07:17 PM.
Le Mans Master
Joined: Feb 2006
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From: Louisiana
That code is usually thrown when the ECM recieves a signal out of it's range for a set number of seconds. The burnoff relay is facing toward the passenger side and the power relay is facing forward. If you follow the link that was provided by vader, it will lead you to the correct way to fix the problem. The code does not mean the relays are bad. It could be a wiring or connection issue at the relays, MAF sensor, or ECM. I would highly advise to troubleshoot from the link above, to save the most money and time. The relays are the same, but unsure of the fan relay being the same. Good luck.
To reset the ECM, disconnect the neg cable to the battery for ~ 30 seconds.
To reset the ECM, disconnect the neg cable to the battery for ~ 30 seconds.
Thread Starter
Drifting
Joined: Dec 2006
Posts: 1,771
Likes: 1
From: Cuyahoga Falls Ohio
That code is usually thrown when the ECM recieves a signal out of it's range for a set number of seconds. The burnoff relay is facing toward the passenger side and the power relay is facing forward. If you follow the link that was provided by vader, it will lead you to the correct way to fix the problem. The code does not mean the relays are bad. It could be a wiring or connection issue at the relays, MAF sensor, or ECM. I would highly advise to troubleshoot from the link above, to save the most money and time. The relays are the same, but unsure of the fan relay being the same. Good luck.
To reset the ECM, disconnect the neg cable to the battery for ~ 30 seconds.
To reset the ECM, disconnect the neg cable to the battery for ~ 30 seconds.
Le Mans Master
Joined: Feb 2006
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From: Louisiana
If you read carefully on the link, it tells you exactly what to do and also gives wire colors for each individual circuits.
First, disconnect the battery as stated above. Reconnect and start the engine. After ~ 1 minute IF the SES light comes on, then turn the engine off. Use a 12-14 ga jumper wire, (preferably one with a 10 amp fuse since the fuel pump circuit has a 10 amp fuse), and connect one end to the pos side of the battery and the other into terminal G of the ALDL (bottom left terminal). This will send battery voltage to the fuel pump circuit and also a few other circuites. Then follow the chart until you find the problem. If you print the link, it will take you all of 30 minutes to find the culprit. Let us know how it goes so we can help.
First, disconnect the battery as stated above. Reconnect and start the engine. After ~ 1 minute IF the SES light comes on, then turn the engine off. Use a 12-14 ga jumper wire, (preferably one with a 10 amp fuse since the fuel pump circuit has a 10 amp fuse), and connect one end to the pos side of the battery and the other into terminal G of the ALDL (bottom left terminal). This will send battery voltage to the fuel pump circuit and also a few other circuites. Then follow the chart until you find the problem. If you print the link, it will take you all of 30 minutes to find the culprit. Let us know how it goes so we can help.
Team Owner
Joined: Dec 2000
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From: SE NY
Cruise-In II Veteran
Since both relays are likely about 19 yrs old it wouldn't hurt to replace them both.
To reset the codes I like to open the connector in the Orn wire near the batt pos terminal for a copla minutes. This drops power to the ECM w/o effecting the presets of the radio, clock, etc.
To reset the codes I like to open the connector in the Orn wire near the batt pos terminal for a copla minutes. This drops power to the ECM w/o effecting the presets of the radio, clock, etc.