sputtering out when i accelerate

Varty Yo

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hi......im having a problem when i step on the gas my cruiser dies for a split second, when i get it moving it keeps jerkin like it loses gas for a second. itsa 67 with the 3.9L. i noticed the tac drop when i step on the gas also. could this be a vacuum prob or fuel pump prob? im very new to cruisers so treat me nice please............thanks guys and gals
 

woody

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not sure what a 3.9 is but...

pull the air cleaner off the top of the carb, look down the bowl and give the linkage a twist...ya should see a stream of fuel from the acellerator pump...if not, then that's plugged...first thing I'd check for...
 
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Mine is a 78' FJ55 w/ a 2F and as soon as it warms up it does the same thing, I've replaced the fuel pump, fuel filter, points, adjusted timing, rebuilt the carb andchecked/repaired all vacume leaks, still does sputtering, could it be vaporizing the gas somewhere?

FUZZ
 

rusty_tlc

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Sound's like the accelerator pump to me. I battled this problem for a long time on my 71. The stock carb has a leather piston arrangement on the accelerator pump. I don't remember for sure but I think you can remove and replace it without dismantling the carb.

If you aren't a purist the best thing to do is ditch the stock carb and replace it with a Weber. I did that 9 years ago on my 74 and haven't looked back. It is by far the best modification I ever made to my 2F.
 

Varty Yo

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thanks guys....i tried takin off the air cleaner then twistng the linkage and the fuel goes into the carb fine. it has 2 fuel filters on it one before the pump and one after, and they are both in glass housings so i can see the fuel inside each one. im sure its not the stock car as the one on it has several vacum hoses not hooked up they are plugged off. the ignition and starter coil have been redone the coil seems to be a brand new unit. it idles fine and only does this when im in gear driving. im stumped as too what to try next. would an electric fuel pump be a better choice then tryin to find a mechanical one?

the carb on it now is: monojet 7042022..... what ever the hell that is
 
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That would be a

Rochester 1 barrel carb.

I would vaccum test it, along with the other considerations.
 

Varty Yo

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vacum test it hey.......by that you mean the carb right? the carb does suck air it whistles when it idles, but only bogs out when drivin. once again im new to cruisers so i dont know where to start.

hey rusty tlc its not the stock carb its rochester 1 barrel does advice still go for that one. i dont see any leather on it?
 

woody

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as you rotate the linkage, you should see a steady small stream of fuel from the acc pump...NOT from the normal jets, but above the primary bowls...if not, plan b....

vacuum...the fact that it's under accelleration leads to a "switched" vacuum line, like one that might connect to a distributor....
 

Varty Yo

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hey woody.........yah the stream is there, but when its idlin its not a stream , and it bogs out......its like a shhhhhhhhhh and almost a mist
 
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Check yer points. My '74 had a similar condition and the points were toast. My problem seemed like misfiring on acceleration (or like it was only running on 4 or 5 cylinders) and got progressively worse in a couple days.

I thought fuel system and timing too because all my ignition system had just been replaced, but turns out the point were fried. I think the root cause is my vacuum advance was sticking. Parts are on the way and I hope to be running normally next week.
 
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