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#2460574 - 03/03/18 03:41 PM 75 Dart Carb Problem
71birdJ68 Offline
master

Registered: 02/09/12
Posts: 4020
Loc: Morristown Tn.
I have a 75 Dart /6 and I'm out of ideas on the carb. About 60% of the time there is a giant hole in the off idle, and mid range power. It will just stagnate, the push the pedal 3/4 down, and the the power comes back. The carb has been rebuilt, but the problem I think is most of the emissions equipment is not working. 75 was the first year for a cat converter, and there all kinds of things under the hood that can't be found new anymore. So, I was thinking of trying a carb from an earlier year that isn't dependent on all that stuff to work correctly. Any ideas on a good range of years to search for?
Thanks

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#2460609 - 03/03/18 05:45 PM Re: 75 Dart Carb Problem [Re: 71birdJ68]
mopars4ever Offline
I Live Here

Registered: 01/20/03
Posts: 11256
Loc: md
Even though you say the carb has been rebuilt it sure sounds like a bad accelerator pump to me. The EGR valve can get stuck open and cause problems too. Some stuff can be found NOS but it will take some searching.

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#2460705 - 03/03/18 10:49 PM Re: 75 Dart Carb Problem [Re: 71birdJ68]
RapidRobert Offline
Circle Track

Registered: 11/20/03
Posts: 34405
Loc: Lincoln Nebraska
actually the '75 MY carb is a good one cuz Ma was now relying on the catcon to take care of alot of the emission requirements as opposed to the earlier discombobulated attempts to federally be emission legal with carb mods (73 MY is the worst) & the other timing systems you mentioned. Keep checking the carb since it being PT tells me the issue might be carb related & when resolved you might plumb the dist right to the carb (ported or manifold depending on what is available) for a power/mileage bennie & definitely bypass the EGR & rework the timing starting with initial.
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#2460736 - 03/04/18 12:30 AM Re: 75 Dart Carb Problem [Re: 71birdJ68]
calrobb2000 Offline
pro stock

Registered: 01/20/03
Posts: 1548
Loc: s. e. pa.
hi

Raise the float level 1/8 higher than carb original spec .

install 1 size larger main jet .

set timing to 16 deg adv at idle .

install green accelerator pump cup .

use original power valve not ones in kit .

make sure dist is advancing properly /with vac adv you want app 50 deg total.

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#2461708 - 03/05/18 07:19 PM Re: 75 Dart Carb Problem [Re: calrobb2000]
71birdJ68 Offline
master

Registered: 02/09/12
Posts: 4020
Loc: Morristown Tn.
Where do you find a green cup? The Standard Motor Parts rebuild kit only had two cups, and one was to big. I put a nos power valve in it, but there is a lot of crap up stream that controls it. There is a box on the inner fender that the potting is running down the fender, so it might be dead also. There is just to much stuff that might not be working, and can't be found. I was just wanting to try an older carb, but wasn't sure what year would be good.

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#2461752 - 03/05/18 08:36 PM Re: 75 Dart Carb Problem [Re: 71birdJ68]
mopars4ever Offline
I Live Here

Registered: 01/20/03
Posts: 11256
Loc: md
Back then there was a recall on the accelerator pump cup and I think the replacement green or orange IIRC. Found this online.
Chrysler Motors Corp.

NHTSA ID No.: 77V-242

Date of Company Notification: 12-23-77

Make: Plymouth

Model: Valiant, Volare

Make: Dodge

Model: Aspen, Dart

Model Year: 1975, 1976, 1977

Number of Vehicles: 1,300,000

Carburetor accelerator pump seal distortion caused by contact with certain type gasoline may result in persistent hesitation or stalling. Also, premature actuation of exhaust gas recirculation (EGR) system may result in persistent cold engine hesitation or stalling. (Correct by replacing pump seal and EGR system retrofit modification.)

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#2461879 - 03/06/18 01:12 AM Re: 75 Dart Carb Problem [Re: 71birdJ68]
calrobb2000 Offline
pro stock

Registered: 01/20/03
Posts: 1548
Loc: s. e. pa.
hi

got a repair kit from advance and it had a green one last time i did this .

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