1980 monza, replacement carb?

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1980 monza, replacement carb?

Postby Rolling7z » Wed Jun 16, 2010 12:04 am

Hi i got a 2.3 with the single barrel rochester that is fubared. What would be best, rebuilding it, or finding a better replacement? also which carbs bolt on?
thanks
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Re: 1980 monza, replacement carb?

Postby ck_carnut » Wed Jun 16, 2010 1:36 pm

I thought the 2.3 was dropped from the Monza around 1977, and they came with the 2.5 Iron Duke after that?

Anyway, assuming you do have the 2.3 Vega motor, I see carbs for the 1bbl manifold quite often on ebay. Might be the easiest way to go.
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Re: 1980 monza, replacement carb?

Postby Rolling7z » Wed Dec 01, 2010 9:02 pm

your correct It is a 2.5 iron duke, and the carb is a rochester vjet 2barrel stupid thing lol. Are there any more accessible carbs that would bolt right onto the intake manifold?
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Re: 1980 monza, replacement carb?

Postby marco_1978_spyder » Wed Dec 01, 2010 9:20 pm

The Varijet is half a Qjet. Much like the 'DualJet' was just the front half of a Qjet, the varijet, for all intensive purposes was a Qjet split in half from front to back leaving one small primary barell and a larger second stage.

Even if there was another carb that would bolt on, nothing will work as good as a properly working varijet on a stock 1980 2.5.

One option would be to find a later F.I. 2.5 roller cam motor. You could probably find a decent used running one for the same or a little more than a new replacement carb ... just a thought. Might not be a pure bolt in either..

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Re: 1980 monza, replacement carb?

Postby HI WINDING MONZA » Wed Dec 01, 2010 10:24 pm

SAME CARBS THAT BOLT ON:

Some early 82-85 S10's / GMC S15's 2.5 and 2.8 V6 has the same carb but a tad bigger CFM. ( computor controlled carbs)

Some late 70's and early 80's AMC Eagles, Spirits , and CJ5 's came with the Pontiac 2.5 /Varijet combo.

80 - 84 X cars FWD also 2.5 - 2.8 V6( Citation, Skylark ,Omega , Phoenix) 81 + computor controled carb

Some early Celebritys also ( 2.5 and 2.8 V6) 81+ computor controlled carb

Some Chevy/ GMC trucks 292 6 cylinder trucks


Easier to just rebuild is my suggestion!

Doug in Az 8)
My Old Monza now lives in Arizona with its newest owner.

The 90's just keep rollin' along........
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Re: 1980 monza, replacement carb?

Postby Rolling7z » Thu Dec 02, 2010 10:30 pm

My main problem with the carb was the accelerator pump, so i mange to find 1 rebuild kit available in my region for this perticular carb, I revuilt the carb wih no extra parts or anything, put the carb on the car, and even with adjusting idle and air mixture, the carb stumbles under light acceleration, its fine at idle and great under heavy acceleration, but I am getting tired of tinkering with this damn thing. I have NO vacume leaks, timing is dead on, engine has had all eco friendly parts taken off... Any last ideas?
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Re: 1980 monza, replacement carb?

Postby res0o7eb » Fri Dec 03, 2010 12:35 am

The off-idle 'stumbling' problem may not be the carburetor.
I was thinking timing, but you've checked that.
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Re: 1980 monza, replacement carb?

Postby starfire383 » Fri Dec 03, 2010 12:01 pm

Have you checked that the vacuum advance isn't leaking or seized?
Does the mechanical advance mechanism move smoothly without binding?
What's going on with the EGR, is it blocked off with a plate or could a disconnected valve be stuck partway open?

Any of those can lead to a bad low speed stumble.

BTW, it's not related to your stumble but you ought to have a secondary air door adjustment. Top of the carb, passenger side, on the top air door linkage. You use a tiny allen wrench and the grub screw faces downward. Take it for a test drive adjusting in quarter turn increments moving to a final 1/8 turn adjustment. You can tune how the second barrel comes in to exactly match your car's weight, power, & gear. Most cars are 300-500 rpm away from their optimum point with the GM setting, and most carburetor rebuild kits do not mention this adjustment.
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Re: 1980 monza, replacement carb?

Postby HI WINDING MONZA » Fri Dec 03, 2010 7:12 pm

Is it an automatic trans car?

Doug in Az 8)
My Old Monza now lives in Arizona with its newest owner.

The 90's just keep rollin' along........
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1992 Pontiac Sunbird Coupe 2.0 OHC MPFI I4 TH125C 157k miles
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Re: 1980 monza, replacement carb?

Postby Rolling7z » Fri Dec 03, 2010 8:27 pm

It is a saginaw 4 speed
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Re: 1980 monza, replacement carb?

Postby HI WINDING MONZA » Sat Dec 04, 2010 11:29 am

Check the fuel filter, it sometimes has a rubber check valve on one end that sticks sometimes ( Fram is famous for it even when brand new) remove it ( the check valve) and try.

Doug in Az 8)
My Old Monza now lives in Arizona with its newest owner.

The 90's just keep rollin' along........
1990 Chevrolet Silverado Regular Cab Long Bed 350 TBI V8 700R4 118K miles
1992 Pontiac Sunbird Coupe 2.0 OHC MPFI I4 TH125C 157k miles
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Re: 1980 monza, replacement carb?

Postby Rolling7z » Sun Dec 05, 2010 2:46 am

Thats a good idea I will check that tomorrow and report back
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