81 vette need help
Thread Starter
Instructor
Joined: Aug 2007
Posts: 116
Likes: 0
From: Temple TX
81 vette need help
Hi guys. I have a 81 vette and it was running fine until a few days ago. I took off the air pump and accessories to it and went to bed. It ran fine when i went to bed. The next day when i started it, it sets at 1500 rpms in park and 1000 in drive. and now when i turn it off, it disels like the motor is gonna jump out the car and die for at least a whole min. What can i do to fix this?
The car has been sitting about 5 years. Could it be timing or vac leaks? or even gas? i am using just the 87 oct gas, should i use higher? thx!
The car has been sitting about 5 years. Could it be timing or vac leaks? or even gas? i am using just the 87 oct gas, should i use higher? thx!
Team Owner
Joined: Aug 2006
Posts: 24,125
Likes: 15
From: Columbia Missouri
Timing may be an issue, but yes the carb will need to be rebuilt it the fuel wasn't treated properly for storage, and you'll want to check to make sure the choke is working properly.
If none of that fixes the idle, adjust it using both the idle mixture screws and the throttle position screw.
If none of that fixes the idle, adjust it using both the idle mixture screws and the throttle position screw.
Drifting
Joined: Jul 2005
Posts: 1,891
Likes: 2
From: Baltimore MD
Hi guys. I have a 81 vette and it was running fine until a few days ago. I took off the air pump and accessories to it and went to bed. It ran fine when i went to bed. The next day when i started it, it sets at 1500 rpms in park and 1000 in drive. and now when i turn it off, it disels like the motor is gonna jump out the car and die for at least a whole min. What can i do to fix this?
The car has been sitting about 5 years. Could it be timing or vac leaks? or even gas? i am using just the 87 oct gas, should i use higher? thx!
The car has been sitting about 5 years. Could it be timing or vac leaks? or even gas? i am using just the 87 oct gas, should i use higher? thx!
Before you start taking things off of an 81 - you gotta remember that the 81 is under the control of the CCC for distributor and carb. So unless you plan on removing the CCC, changing the distributor and the carb, don't go mucking to much with the carb settings.
Safety Car
Joined: May 2001
Posts: 3,758
Likes: 3
From: Surrey
Taking off the air pump shouldn't affect the computer in any way, but what other accessories did you remove? The high idle, etc, makes me suspect a vacuum leak, so have a good root about & see if you've left any ports open, or pipes unconnected. If you can't find anything, you could try temporarily diconnecting vac pipes at the carb (one at a time), plugging the hole (at the carb) & seeing if it improves. If it does then you've found the pipe that leads to the leak (assume the gas is fresh & not the stuff that's been in there 5 years?).
I wouldn't touch the carb until you are sure that it's nothing to do with what you did prior to it starting to play up. As IrishJoker said, the computer is controlling the carb, so it's not like a normal one & needs treating in a different way (if it was a woman, it'd be a red head). The good news is that the computer doesn't care about the air pump & other emissions stuff. It just switches it all on/off & doesn't care whether it does or not.
Does the Check Engine light come on/flash at all while all this is going on?
Your big mistake was going to bed. Quite often when I do that I wake up to things going wrong all around me
I wouldn't touch the carb until you are sure that it's nothing to do with what you did prior to it starting to play up. As IrishJoker said, the computer is controlling the carb, so it's not like a normal one & needs treating in a different way (if it was a woman, it'd be a red head). The good news is that the computer doesn't care about the air pump & other emissions stuff. It just switches it all on/off & doesn't care whether it does or not.
Does the Check Engine light come on/flash at all while all this is going on?
Your big mistake was going to bed. Quite often when I do that I wake up to things going wrong all around me
Le Mans Master
Joined: Jan 2006
Posts: 9,192
Likes: 27
From: Boca Raton Florida
Probably a vac leak you created. Look over all the TVS's and make sure they are all connected to something or capped. running fine at night and high idle in the am says the choke is on and maybe a vac leak.
Thread Starter
Instructor
Joined: Aug 2007
Posts: 116
Likes: 0
From: Temple TX
thank you for all your replies. It actually is running right for the time being now but i know i need to figure out what is up. The car had been sitting for 5 years before i bought it just last week so i KNOW it has vac leaks all over the place. I did cover up all the spots which i did take anything off. I also plan on replacing every single vac line very soon. The engine light does come on and off randomly. As i said...its running right at the moment, no diseling and no rpm problems...its like it has a mind of its own..upset for setting for 5 years perhaps? 
I also do intend on replacing the intake, carb and distrib eventually to get rid of that awful computer but I would like to make it work for the time being ^^. I will keep you updated on anything which might occur.
I also do intend on replacing the intake, carb and distrib eventually to get rid of that awful computer but I would like to make it work for the time being ^^. I will keep you updated on anything which might occur.
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Thread Starter
Instructor
Joined: Aug 2007
Posts: 116
Likes: 0
From: Temple TX
Alright guys! Update and a lesson learned...although it makes me feel like a newbie...but I am to corvettes! :P
Anyways, Got my 81 vette to stop idleing funny and diseling...the linkages on the carb were sticking! I lubed them and everything seems to be fine so far.
Lesson learned - check your carb 100% if the vehicle has been sitting. BUT it is running pretty rich and I dont know what to do about that because fuel mixture on a 81 is all computer controlled right?
Anyways, Got my 81 vette to stop idleing funny and diseling...the linkages on the carb were sticking! I lubed them and everything seems to be fine so far.
Lesson learned - check your carb 100% if the vehicle has been sitting. BUT it is running pretty rich and I dont know what to do about that because fuel mixture on a 81 is all computer controlled right?
