81 Computerized Carb/Dist
Thread Starter
Instructor
Joined: Jan 2007
Posts: 195
Likes: 2
From: Wilmington MA
81 Computerized Carb/Dist
I wasnt happy w performance of my 81 computerized carb and distributor. So i read some old threads on swapping out to the older style and read you need to change both the carb and distributor if going to the non-computer carb and older vacuum advance type dist.
So i searched out the parts and installed both. The distributor did not produce any spark. It had a four wire connector like the computer type and was supposed to be interchangable. So i re-installed the computer driven dist and set the timing. Worked perfectly w the standard non-comp carb w better performance.
The only question that remains is: Are the computer driven and non-computer distributors interchangable???
The correct answer will tell me how to proceed. If they are, then i will look towards inoperable components inside the dist. If not, then I'll be going in another direction.
Anybody??
So i searched out the parts and installed both. The distributor did not produce any spark. It had a four wire connector like the computer type and was supposed to be interchangable. So i re-installed the computer driven dist and set the timing. Worked perfectly w the standard non-comp carb w better performance.
The only question that remains is: Are the computer driven and non-computer distributors interchangable???
The correct answer will tell me how to proceed. If they are, then i will look towards inoperable components inside the dist. If not, then I'll be going in another direction.
Anybody??
Le Mans Master
Joined: Jan 2006
Posts: 9,192
Likes: 27
From: Boca Raton Florida
No they are not interchangeable. I also do not think your going to get any serious performance gains from deleting the CCC controlled carb and dist. What WILL get you serious gains are: Good Dual exhaust, better cam, better heads. Those are the bottlenecks for that motor
Drifting
Joined: May 2007
Posts: 1,491
Likes: 2
From: North Royaton Ohio
Don't you need a different distributor since there's no vacuum advance on the 81 and it's computer controlled? If you remove the CCC and use the regular distributor, then you don't have any kind of advance, allowing the motor to run, but sluggishly, so you'd have to swap out to a different distributor. Am I totally wrong here, because I could be, but I think that that's true. Also, does that mean that an aftermarket distributor is out of the question?
Le Mans Master
Joined: Jan 2006
Posts: 9,192
Likes: 27
From: Boca Raton Florida
Nope, you got it right. The CCC controls the timing on an 81. The car will run, but with no advance like you said it will be slugish.
There are a couple reasons to keep the CCC, Dist and carb. The carb is a 750, thats good for 350hp or better and the fuel/air mix solenoid is capable of managing that range. There are no moving parts in the ignition except for the rotor in the cap, good solid system. About the only improvement is a hotter coil and maybe a newer chip that improves the dwell a bit. But those contributions are small to overall HP gains. The system can handle bigger cam, heads, exhaust. When you change them you don't even have to rejet the primary side, possibly the secondaries. I will let you know for sure when I get mine rolling.
So, keep the CCC, Carb and dizzy and spend your money on exhaust and heads and cam. Then if that don'e get it for you go with a different carb
There are a couple reasons to keep the CCC, Dist and carb. The carb is a 750, thats good for 350hp or better and the fuel/air mix solenoid is capable of managing that range. There are no moving parts in the ignition except for the rotor in the cap, good solid system. About the only improvement is a hotter coil and maybe a newer chip that improves the dwell a bit. But those contributions are small to overall HP gains. The system can handle bigger cam, heads, exhaust. When you change them you don't even have to rejet the primary side, possibly the secondaries. I will let you know for sure when I get mine rolling.
So, keep the CCC, Carb and dizzy and spend your money on exhaust and heads and cam. Then if that don'e get it for you go with a different carb
Thread Starter
Instructor
Joined: Jan 2007
Posts: 195
Likes: 2
From: Wilmington MA
Hi, Sixfooter,
The distributor i tried to replace the CC distributor was one w a vacuum advance.
The whole thing that started it was, when i am running in any gear below 2000rpm, and i would press the gas slightly, it would stumble. Had the carb rebuild by a very reputable carb outfit and no improvement. They even looked at it a second time. Still no improvement. Whent all over this thing re vacuum leak-nothing. definatly a carb issue.
This non computer carb on it now is off a 79 L82 and runs great. No stumbling and great throttle response. seems to be ok w the computer distributor.
Think i should leave it or search out another computer carb?
Frank
The distributor i tried to replace the CC distributor was one w a vacuum advance.
The whole thing that started it was, when i am running in any gear below 2000rpm, and i would press the gas slightly, it would stumble. Had the carb rebuild by a very reputable carb outfit and no improvement. They even looked at it a second time. Still no improvement. Whent all over this thing re vacuum leak-nothing. definatly a carb issue.
This non computer carb on it now is off a 79 L82 and runs great. No stumbling and great throttle response. seems to be ok w the computer distributor.
Think i should leave it or search out another computer carb?
Frank
Le Mans Master
Joined: Jan 2006
Posts: 9,192
Likes: 27
From: Boca Raton Florida
Sounds like the Acc pump was not working. Do you know if they went thru the troubleshooting proceedure in the manual? The book is actually pretty smart. I'll look it up and see what it says
Thread Starter
Instructor
Joined: Jan 2007
Posts: 195
Likes: 2
From: Wilmington MA
By Acc pump, do you mean the air "smog" pump? If so, it is not installed on this motor. I siezed and i took off the other plumbing that went with it. I'm in MA and dont need emmissions any longer. I was gravitating towards a standard non emissions set up w side pipes.
How does the air pump effect fuel mix in these computer set ups?
How does the air pump effect fuel mix in these computer set ups?
Safety Car
Joined: Mar 2000
Posts: 4,078
Likes: 27
From: Northeast South Dakota
The accelerator pump is inside the carb. It hooks directly to linkage off of the arm on the carb. When you step on the pedal it gives and extra shot of gas immediately to prevent stumbles. I would tend to guess that the carb shop that did you carb doesn't know anything about the E4ME. There are virtually none that do. The info you would need is on this forum. But, if you like the carb that you switched to then run it. Whatever makes you happy.
-Justin
-Justin
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