81 carb/computer problems ???
Thread Starter
Intermediate
Joined: May 2007
Posts: 37
Likes: 1
81 carb/computer problems ???
is there a reference on how this system works ? ive spent money with the local experts, this carb has been rebuilt by the best but the car still starts rough, idles poorly, when put into gear the rpm drops so low it doesnt want to run, is there a guide that i can check voltage at the different hook ups , im considering converting to standard carb and doing away with computor do i need to change distributor if i do that any suggestions thanks
Team Owner
Joined: Jan 2007
Posts: 53,648
Likes: 878
From: Southern Cal Ca
St. Jude Donor '22
is there a reference on how this system works ? ive spent money with the local experts, this carb has been rebuilt by the best but the car still starts rough, idles poorly, when put into gear the rpm drops so low it doesnt want to run, is there a guide that i can check voltage at the different hook ups , im considering converting to standard carb and doing away with computor do i need to change distributor if i do that any suggestions thanks
This motor is hot blooded, meaning it needs minutes for the O2 and Coolant sensors to get hot.
Do you have a check engine light on?
do you hear the clicking of the M/C sol on the carb?
A choke properly set.
There is a green pigtail/connector used to check M/Control of the
carb. It is on the main harness running up the pass side of engine,
about the rear of A/C compressor area.
you will need a dwell meter set on 6 cyl range to check
the Mixture/Control sol on top of carb. 30-35 deg is average
Team Owner
Joined: Jan 2007
Posts: 53,648
Likes: 878
From: Southern Cal Ca
St. Jude Donor '22
unplugged = full rich
Kind of what I was thinking, vacuum leak.
this will affect any carb you might use.
Best thing is get a good manual.
Team Owner
Joined: Jan 2007
Posts: 53,648
Likes: 878
From: Southern Cal Ca
St. Jude Donor '22
Factory Service Manual
Check the usual EBay, craigs, Vet Vendors, ect
http://www.helminc.com/helm/homepage...ient=firefox-a
http://www.helminc.com/helm/Result.a...RLER02KRC87MM4
Check the usual EBay, craigs, Vet Vendors, ect
http://www.helminc.com/helm/homepage...ient=firefox-a
http://www.helminc.com/helm/Result.a...RLER02KRC87MM4
Race Director
Joined: Dec 2004
Posts: 14,989
Likes: 2
Kind of a quick rule of thumb.....
If the engine is running ok in park or neutral(idles fine, revs fine), then goes to crap when put in drive, it's usually not the carb. Nothing in the carb is going to change going from neutral to drive to make those kinds of problems happen.
However, there are changes in the ignition system that will.
If the engine is running ok in park or neutral(idles fine, revs fine), then goes to crap when put in drive, it's usually not the carb. Nothing in the carb is going to change going from neutral to drive to make those kinds of problems happen.
However, there are changes in the ignition system that will.
Last edited by nitronick; Aug 15, 2009 at 02:02 PM.
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Le Mans Master
Joined: Oct 2000
Posts: 6,362
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From: Oak Harbor WA
What is the RPM when cold started? Does the RPM increase at all at idle with car in Park while cold? Did you follow the instructions on the emissions sticker located on the underside of the hood? There are four steps listed.
Melting Slicks
Joined: Mar 2006
Posts: 2,465
Likes: 0
From: Orange Park Fl
is there a reference on how this system works ? ive spent money with the local experts, this carb has been rebuilt by the best but the car still starts rough, idles poorly, when put into gear the rpm drops so low it doesnt want to run, is there a guide that i can check voltage at the different hook ups , im considering converting to standard carb and doing away with computor do i need to change distributor if i do that any suggestions thanks
My first advise is, figure out where the problem really is. I've seen people mindlessly blame the CCC system and waste hundreds of dollars for an inferior carb and ignition system (yes, you have to replace the distributor if you loose the computer), only to find they still had the same exact problem as before (vacuum leak, fouled plug, bad fuel pump, etc.)
God bless, Sensei
Race Director
Joined: Dec 2004
Posts: 14,989
Likes: 2
Who are your experts? The '81 CCC system is simple and reliable, and is an upgrade over a standard carb and no computer. But it is sometimes hard to find competent people to work on it. That's why I studied and became my own expert.
My first advise is, figure out where the problem really is. I've seen people mindlessly blame the CCC system and waste hundreds of dollars for an inferior carb and ignition system (yes, you have to replace the distributor if you loose the computer), only to find they still had the same exact problem as before (vacuum leak, fouled plug, bad fuel pump, etc.)
God bless, Sensei
My first advise is, figure out where the problem really is. I've seen people mindlessly blame the CCC system and waste hundreds of dollars for an inferior carb and ignition system (yes, you have to replace the distributor if you loose the computer), only to find they still had the same exact problem as before (vacuum leak, fouled plug, bad fuel pump, etc.)
God bless, Sensei
I can't count the times I've had customers come in with a 4' long printout showing (among other things) the MC solenoid reading "is off", not understanding that, some other system is malfunctioning will force the computer to try and adjust the mixture to compensate.
Drifting
Joined: Apr 2006
Posts: 1,911
Likes: 2
From: gold coast queensland
im on the other side of the fence. i couldnt wait to get my ccc out along with the 3miles of wiring connected to it yada yada yada and hit it with the biggest hammer i could find.i then put in msd dizzy, demon carb, non loc up transmission and i have been smiling ever since.
Racer
Joined: Oct 2007
Posts: 431
Likes: 22
From: Chester Illinois
also have an 81 and fought this problem for 3 months. finally a new m/c solenoid and computer took care of the problem. also had carb rebuilt and properly adjusted. my check engine light did not come on even with the key in the on position and no start. it does now and runs as good as an 81 will. namvet
Melting Slicks
Joined: Mar 2006
Posts: 2,465
Likes: 0
From: Orange Park Fl
Mixture Control. It is an internal part of the E4ME Quadrajet carb that replaced the old vacuum operated power piston. The two wire connector on top of the carb on the passenger side is the MC solenoid connector. The solenoid controls the depth of the primary rods in their jets by voltage from the computer, which varies mixture according to the O2 content of the exhaust, manifold vacuum, engine RPM and throttle position.
God bless, Sensei
God bless, Sensei
Heel & Toe
Joined: Feb 2009
Posts: 22
Likes: 0
I have an 81 and had the same problem and found the bulk of my problems with vacume leaks. Had more than one vacume leak. Be sure to check the vacume system on the headlight system, mine still went up and down but had a leak in the canister. Hope this helps. I have found the bulk of driveability problems were not the ccc problems.
Thread Starter
Intermediate
Joined: May 2007
Posts: 37
Likes: 1
THANKS for the encouragement, found both thermal switchs have vacumn leaks and get worse as they are heated, low vacumn was allowing the heat riser to only partially open. its getting better thanks to all
