81 with Code 44, Little Help Please
Thread Starter
Pro
Joined: Dec 2008
Posts: 683
Likes: 114
From: Hamilton Ohio
No, I still have an intermittent CEL. I've read the diagnostic procedures also, somewhat intimidating.
The CEL only comes on for about 15 to 20 seconds while cruising at a steady speed for 1.5 to 2.0 miles or so, then it goes off. If you constantly change speeds slightly, faster or slower, it will not come on. Funny thing is though, the car is running beautifully. Pulls good from stop, no hesitation, no weird noises, nothing.
New O2 sensor is Bosch brand, maybe it's a bad one? Have heard bad stories about Bosch sensors. Maybe should have bought an AC Delco.
I can live with it for now, just really bothers me when it (CEL) comes on.
May have to take it to someone with more experience with this type of problem.
Thanks again for your help.
The CEL only comes on for about 15 to 20 seconds while cruising at a steady speed for 1.5 to 2.0 miles or so, then it goes off. If you constantly change speeds slightly, faster or slower, it will not come on. Funny thing is though, the car is running beautifully. Pulls good from stop, no hesitation, no weird noises, nothing.
New O2 sensor is Bosch brand, maybe it's a bad one? Have heard bad stories about Bosch sensors. Maybe should have bought an AC Delco.
I can live with it for now, just really bothers me when it (CEL) comes on.
May have to take it to someone with more experience with this type of problem.
Thanks again for your help.
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,116
From: Crossville TN
You did reset the computer after you changed the O2 sensor, didn't you? If not, the Code 44 is probably left over from the O2 sensor problem (which you have fixed). An intermittant CEL usually doesn't throw a code to the computer. Since it is an '81 car, I'd guess that your electronic Q-jet needs to be checked (per the Chevrolet Chassis Service Manual tests) and maybe adjusted (also per same manual). It could also be a temp sender going bad. But the intermittant CEL signal isn't a 'serious' problem...you can still drive it and, apparently, it runs well; so I doubt that the computer has any problems.
Thread Starter
Pro
Joined: Dec 2008
Posts: 683
Likes: 114
From: Hamilton Ohio
Yes, I've reset the computer after changing the O2 sensor. And a couple of more times after that.LOL I read that too about the carb possibly needing adjustment. I agree with you, it's not a serious problem at all, but that damn light just aggravates the crap out of me.
Like I said I may have to take this to someone with a little more knowledge about this this than I have.
Like I said I may have to take this to someone with a little more knowledge about this this than I have.
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,116
From: Crossville TN
Since the '81 car had such a 'simple' ECU system (processor, ignition module, O2 sensor, temp sensor, elect. carb), there are only so many things it can be. The O2 sensor has been replaced and your symptoms (or, rather, lack of any significant symptoms) somewhat eliminates the computer as the problem source. That leaves the temp sensor and the carb. If a replacement temp sensor is not too expensive, you might want to try that....it is almost 30 years old; but the likely source is the carb being a bit out of adjustment (it's 30 years old, too). Those two units would be where I put my efforts, and it's your call as to which you work with first. Good luck with your troubleshooting. Please let us know what work you've done and the results you get. 
P.S. I didn't include the ignition module because it is most likely a "works or doesn't work" type component. It could just be a bit heat sensitive, however. I still believe it would be last on my list to change.
P.S. I didn't include the ignition module because it is most likely a "works or doesn't work" type component. It could just be a bit heat sensitive, however. I still believe it would be last on my list to change.
Thread Starter
Pro
Joined: Dec 2008
Posts: 683
Likes: 114
From: Hamilton Ohio
Thanks 7T1vette, for your help especially, and everybody else's with this
. I might try a new Temp Sensor, only $20-$25.00. Like you said, everything is 30 years old or so. Could be the Carb is out of adjustment or I have a small vacuum leak. If and when I find the problem, and the fix, I'll be sure to post and let you know.
, and everybody else's with this. I might try a new Temp Sensor, only $20-$25.00. Like you said, everything is 30 years old or so. Could be the Carb is out of adjustment or I have a small vacuum leak. If and when I find the problem, and the fix, I'll be sure to post and let you know.
Melting Slicks
Joined: Mar 2006
Posts: 2,465
Likes: 0
From: Orange Park Fl
Here is the last word on this problem. The GM Service Manual has litanies that takes you through, step by step, the testing sequence to find any problem. If you want to be able to competently and confidently fix your own car, you need this book. Since few have the desire to do quality work on these old vehicles and even fewer actually have the needed knowledge (the dealerships and local shops threw out the '81 Service Manual years ago), I consider the GM Manual a "must have".
http://cgi.ebay.com/ebaymotors/1981-...sQ5fLiterature
This one's a bit pricey, but if you look for a while you should be able to pick one up for around half of that (I got mine for $9 missing the front cover about five years ago).
God bless, Sensei
http://cgi.ebay.com/ebaymotors/1981-...sQ5fLiterature
This one's a bit pricey, but if you look for a while you should be able to pick one up for around half of that (I got mine for $9 missing the front cover about five years ago).
God bless, Sensei
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,116
From: Crossville TN
sensei...
The book in the site you listed is the "Shop Manual" and I think that is the same as the 'Chassis Overhaul Manual'. That manual has all of the rebuild procedures for carb, brakes, steering, suspension. transmission, engine, etc. But, I believe the 'Chassis Service Manual' is the one with the system troubleshooting detail and the carb testing and adjustment procedure. My memory isn't all it used to be...and perhaps both of these Chevy manuals had the emissions systems adjustments in them, but I know that in prior years, the Service Manual had that info.
P.S. I have never had the manuals for the '81 car, so if they changed their content strategy after the mid-70's, I'd be 'out-to-lunch' on that one.
The book in the site you listed is the "Shop Manual" and I think that is the same as the 'Chassis Overhaul Manual'. That manual has all of the rebuild procedures for carb, brakes, steering, suspension. transmission, engine, etc. But, I believe the 'Chassis Service Manual' is the one with the system troubleshooting detail and the carb testing and adjustment procedure. My memory isn't all it used to be...and perhaps both of these Chevy manuals had the emissions systems adjustments in them, but I know that in prior years, the Service Manual had that info.
P.S. I have never had the manuals for the '81 car, so if they changed their content strategy after the mid-70's, I'd be 'out-to-lunch' on that one.
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Melting Slicks
Joined: Mar 2006
Posts: 2,465
Likes: 0
From: Orange Park Fl
I have never seen the original 1981 GM Corvette Service Manual for sale in reprint anywhere. There are plenty of aftermarket manuals (I own them all), but none have the specific information needed to troubleshoot the unique 1981 E4ME/ CCC system except the old GM manual the dealerships used. It has flow charts for the trouble codes so you can trace down the exact problem, not just throw parts at it. Again, it is a "must have".
God bless, Sensei
God bless, Sensei
Le Mans Master
Joined: Jan 2006
Posts: 9,192
Likes: 27
From: Boca Raton Florida
I have an extra copy of that book on hand, anyone interested? I'd like to get about $30 for it, less than I paid. I a copy with color electrical a little after I got this one so this one is barely even used.
