Ok so ive been having some issues with my car trying to stall out when I press the gas down too fast. It only does it from a stop or at low speeds me and my grandpa have figures that its the accelerator pump and I found in an old manual that its adjustable question is how do I do that properly because the instructions are confusing in the book its a holley 1945 1bbl carb anyone have an imput on this subject?
accelerator pump issues
- Thread starter JRDART
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66aCUDA
/6 Racer
slantsix.org has repair manuals and training video's in the engine section as a FAQ at the top.
Frank
Frank
cudamark
Well-Known Member
Yea, you should probably get a factory service manual to verify what the settings should be. If nobody has messed with it in the past, just replace the accelerator pump and return the linkage to the same spot. There are three slots for the acc. pump link rod and the link rod has a loop in it that can be adjusted by bending it. The pump should start a fuel stream from the very start of the linkage movement and continue all the way throught the range of the throttle shaft without binding or preventing the throttle from opening up all the way.
well i have a chiltons manual made specificaly for the 75 year the thing is that it says to put it in the middle slot and the rod should measure 2.22 in...wtf would 2.22 measure out to in fractions lol. but it also dont make any sence because the rocker plate goes in the opposite direction that the pump rod needs to go to activate it. meaning that while looking at the engine from the front the rocker plate rotates ---> while in order to activate the pump it needs to pull the rod <---...its all very confusing really...and yea Lex its a pain in the butt. however it only hesitates at low speeds.
cudamark
Well-Known Member
There is a spring inside the 1945 carb that pushes the acc. pump down. The linkage doesn't do the pushing.....it pulls the acc pump back to it's starting point. Changing the slot or the length of the linkage changes the pump stroke and therefor the amount of fuel discharged from the outlet nozzle. Look down the throat of the carb and move the linkage. Fuel should squirt from the nozzle from the very first movement of the linkage. If not, the engine will hestate and/or die. If there is no fuel discharged or it just dribbles a little, you'll need to take the carb apart and clean/repair/replace as necessary to get it working again.
what if i can hear a suction sound when i move the lever...and i did it one time with the motor running and it killed it...any thoughts?..you guys are really a big help i think i almost got her licked
The accelerator pump isn't a part that should require periodic adjustment.
The setup info in the service manual is meant for rebuilding a carb. Probably be easier to understand also.
You might find something else wrong in there too. Venturi bleed tubes drop out of place especially in Carter and Rochester carbs and cause a stumble off idle.
The setup info in the service manual is meant for rebuilding a carb. Probably be easier to understand also.
You might find something else wrong in there too. Venturi bleed tubes drop out of place especially in Carter and Rochester carbs and cause a stumble off idle.
slantsixdan
=..=
Chilton manuals are useless. So are poor-quality carburetor kits. Get a good kit from www.daytonaparts.com , get a new brass float (Walker p/n 100-48 ) to replace the nitrophyll foam one. Disassemble, thoroughly clean, rebuild, and adjust the carb in accord with the Carburetor operation and repair manuals posted here for free download.
And check the routing of the distributor vacuum advance hose. It should go directly from the spark port on the carburetor to the distributor, with no stops in between. If it stops at a widget on your air cleaner, reroute it so it goes directly from carb to distributor.
And check the routing of the distributor vacuum advance hose. It should go directly from the spark port on the carburetor to the distributor, with no stops in between. If it stops at a widget on your air cleaner, reroute it so it goes directly from carb to distributor.
I have been through the manuals on that website..thank you Dan. However as far as the vacuum line to the dizzy its all one line no cracks or tears..and thats the only vacuum line thats ran to the carb aside from the choke. anyhow i really appreciate the advice..any other input it welcomed.
cudamark
Well-Known Member
Check the pump output with the engine off.......
TripleJackInGA
Master of None
I'm having the exact same issue on my car. 72 Dart 225/Auto with 55k miles. No modifications, and everything at least looks stock and unmolested, just from looking.
I also read somewhere else that in older carbs, there's an o-ring on the acc. pump that newer ethanol-based gasoline can swell/distort.
I'll be using the tips here when I get a chance to look at mine closer.
Thanks!
I also read somewhere else that in older carbs, there's an o-ring on the acc. pump that newer ethanol-based gasoline can swell/distort.
I'll be using the tips here when I get a chance to look at mine closer.
Thanks!
TripleJackInGA
Master of None
I'm having the exact same issue on my car. 72 Dart 225/Auto with 55k miles. No modifications, and everything at least looks stock and unmolested, just from looking.
I also read somewhere else that in older carbs, there's an o-ring on the acc. pump that newer ethanol-based gasoline can swell/distort.
I'll be using the tips here when I get a chance to look at mine closer.
Thanks!
I also read somewhere else that in older carbs, there's an o-ring on the acc. pump that newer ethanol-based gasoline can swell/distort.
I'll be using the tips here when I get a chance to look at mine closer.
Thanks!
slantsixdan
=..=
TripleJack, what you've heard about is the leather pump plunger cup on Carter BBS and BBD carburetors. There's no such cup on the Holley 1920 in your '72 Dart—it uses a rubber diaphragm instead but it does have accelerator pump parts that will fail with age, especially if they've been sitting a long time. Pick up a good quality carb kit; I like the ones from www.daytonaparts.com , and head here for the info you'll need to get your carb working right.
I don't think I can add much to this post, but perhaps add that I have a similar issue.
When I restored my 72 Scamp almost 10 years ago, I sent the carburetor to Holley for a rebuild. As long as I can remember the car had a problem where you have to really feather the gas from a stop or almost stopped or the car simply shuts off. When driving or cruising flooring the panel causes the car to downshift and it acts fine.
If memory serves me, I even sent back the Holley to have it double checked and they said everything was fine.
I haven't played with the car for a while, so I don't exactly remember all the exact details. I do know that when I first started driving the car after the restoration the timing was set correctly and to be honest I got tired of playing with it and lived with the way it was.
If anyone has any thoughts on that, I'd be glad to hear it.
When I restored my 72 Scamp almost 10 years ago, I sent the carburetor to Holley for a rebuild. As long as I can remember the car had a problem where you have to really feather the gas from a stop or almost stopped or the car simply shuts off. When driving or cruising flooring the panel causes the car to downshift and it acts fine.
If memory serves me, I even sent back the Holley to have it double checked and they said everything was fine.
I haven't played with the car for a while, so I don't exactly remember all the exact details. I do know that when I first started driving the car after the restoration the timing was set correctly and to be honest I got tired of playing with it and lived with the way it was.
If anyone has any thoughts on that, I'd be glad to hear it.
ok so after a long while I finally got around to looking over my carb. tested the pump with the engine off and it puts out a healthy stream. However if I blip the throttle it still cuts out for a second like it wants to die and then it finally catches and revs up...any ideas?
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