rough idle
Drifting
Joined: Mar 2013
Posts: 1,952
Likes: 239
From: Venice Cali.
Make sure no vacume leak. When u tighten down maf sensor make sure reading is .54 the whole time. Clean and lube the other connectors with dielectric grease and cleaner.unhook battery and try again.i had same code situation.
Race Director
Joined: Apr 2002
Posts: 10,036
Likes: 346
From: Anaheim CA
You said "set base idle". I assume that means that you did a "minimum idle adjustment", as shown here:
http://forums.corvetteforum.com/1570563689-post1.html
That adjustment procedure includes setting the TPS output voltage at idle. Doing that should get rid of the error code 22.
Error code 33 can happen if the MAF is unplugged, the connector pins are dirty or a wire is broken. I think you can also get this error if the MAF power relay is bad. That would be the MAF burnoff module in an '85 (you neglected to specify the year).
Error code 45 is an O2 sensor problem. Could be a bad O2 sensor, bad connector or broken wire.
My recommendation to you is to reset the ECM, either the easy way by disconnecting the ECM reset connector (if your car has one) or the hard way by disconnecting a battery cable. You only need to do the disconnect for a second or so, despite what some people say. After doing the ECM reset, check for codes again. They might have "fixed themselves".
A rough idle is almost always a vacuum leak. It can be bad plugs or plug wires, but that is rare.
http://forums.corvetteforum.com/1570563689-post1.html
That adjustment procedure includes setting the TPS output voltage at idle. Doing that should get rid of the error code 22.
Error code 33 can happen if the MAF is unplugged, the connector pins are dirty or a wire is broken. I think you can also get this error if the MAF power relay is bad. That would be the MAF burnoff module in an '85 (you neglected to specify the year).
Error code 45 is an O2 sensor problem. Could be a bad O2 sensor, bad connector or broken wire.
My recommendation to you is to reset the ECM, either the easy way by disconnecting the ECM reset connector (if your car has one) or the hard way by disconnecting a battery cable. You only need to do the disconnect for a second or so, despite what some people say. After doing the ECM reset, check for codes again. They might have "fixed themselves".
A rough idle is almost always a vacuum leak. It can be bad plugs or plug wires, but that is rare.
Last edited by Cliff Harris; Nov 29, 2013 at 01:07 AM.
Burning Brakes
Joined: Mar 2012
Posts: 769
Likes: 22
From: California
FL Events Coordinator
St. Jude Donor'13
I had a rough idle like 2 or 4 days ago and threw a bunch of parts at it, it needed it anyway. Parts like new plenum and runner gaskets which where causing a minute vacuum leak and a fuel filter. It helped a little with the rough idle by fixing the vacuum leak, but overall it ended up being the timing was off. Maybe try the other things first and then check your timing so see if it is right.
My timing being off was also setting a code for the oxygen sensor since the timing was making it run to rich.
My timing being off was also setting a code for the oxygen sensor since the timing was making it run to rich.
