carb dash pot vacuum

dynamic88 · 07-28-2007, 04:20 PM

i have a 65 olds dynamic 88 convertable with a 425 v8 motor. i was wondering exactly what the dash pot vacuum does. i believe it cracks the carbruator open when you first start ituntil it warms up. but im not sure. i have been recently having trouble with the car running rough when it is first started. it acts like it wants to die and it has been idealing high until it gets warmed up and thenits fine. the carbruator has been rebuilt and tuned. the pot vacuum is looking pretty old. dont know if this is the calprit or not. what do you think. also if it is does anyone know where i can get another one. i have checked my local parts store and they seem to be a thing of the past. if a guy cant get them what else can a guy do to get around this problem if they can. thanks chris

442Harv · 07-30-2007, 07:04 AM

Do you have a hand vac pump? Hook it up and see if it is working, or take the hose off and see. if you can feal vacume, or it may be leaking? I bought one at Car Quest a while back. I have a good parts man and he had to do a lot of looking to find one, did not just come up on their computor. May have to fing a good used carb and take one off? I don't think it will effect you car running at a idle, or normal driving, only when you step on it to open up the rear barrells.

442Harv · 07-30-2007, 09:13 AM

Chris,just wanting to make sure, I understood you correct, and not miss leading you. You are talking about the piece on the choke side, right? Sometimes a couple off carb parts get call different things to different guys. The piece on the driver side, is a part, I think you will have a hard time finding,I think is called a dashpot. I was talking about the choke side vac piece, hope I diddent miss lead you? Harv

dynamic88 · 07-30-2007, 12:29 PM

no its the dash pot and im having a hard time finding one. ive been told that it keeps the pedal from coming back to fast. i dont know if a guy could rig up something different or not. chris

joe_padavano · 07-30-2007, 01:13 PM

Quote:

Originally Posted by dynamic88

no its the dash pot and im having a hard time finding one. ive been told that it keeps the pedal from coming back to fast. i dont know if a guy could rig up something different or not. chris

The first question is what carb is this? 2GC, 4GC, or Qjet? I'm guessing it's a 4GC?

dynamic88 · 07-30-2007, 02:01 PM

joe its a 425 rockchester 2 barrel

joe_padavano · 07-30-2007, 03:35 PM

Quote:

Originally Posted by dynamic88

joe its a 425 rockchester 2 barrel

In that case the vac diaphragm is a choke pulloff that's designed to help open the choke a little once the engine starts. Once the engine warms up and the choke is fully open, it really doesn't do anything.

dynamic88 · 07-30-2007, 05:39 PM

i started calling companys out of the olds section of hemmings. i found a company in washington state that deals in nos and repop for cars and they had some of the dash pots. original gm was 72.00 and a remanufactured one was 20.00, so i took the 20.00 dollar one and its on its way. ive checked alot of places and thought i was going to be out of luck, but i guess not. chris whats a good parts number book to get for this 65 olds dynamic 88. i need something that has a break down with gm numbers so i can find parts a little easier. thanks chris

07-28-2007, 04:20 PM	#1 (permalink)
dynamic88 Senior Member Join Date: Oct 2006 Posts: 160	carb dash pot vacuum i have a 65 olds dynamic 88 convertable with a 425 v8 motor. i was wondering exactly what the dash pot vacuum does. i believe it cracks the carbruator open when you first start ituntil it warms up. but im not sure. i have been recently having trouble with the car running rough when it is first started. it acts like it wants to die and it has been idealing high until it gets warmed up and thenits fine. the carbruator has been rebuilt and tuned. the pot vacuum is looking pretty old. dont know if this is the calprit or not. what do you think. also if it is does anyone know where i can get another one. i have checked my local parts store and they seem to be a thing of the past. if a guy cant get them what else can a guy do to get around this problem if they can. thanks chris

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07-30-2007, 07:04 AM	#2 (permalink)
442Harv Member Join Date: Mar 2007 Posts: 62	Do you have a hand vac pump? Hook it up and see if it is working, or take the hose off and see. if you can feal vacume, or it may be leaking? I bought one at Car Quest a while back. I have a good parts man and he had to do a lot of looking to find one, did not just come up on their computor. May have to fing a good used carb and take one off? I don't think it will effect you car running at a idle, or normal driving, only when you step on it to open up the rear barrells.

07-30-2007, 09:13 AM	#3 (permalink)
442Harv Member Join Date: Mar 2007 Posts: 62	Chris,just wanting to make sure, I understood you correct, and not miss leading you. You are talking about the piece on the choke side, right? Sometimes a couple off carb parts get call different things to different guys. The piece on the driver side, is a part, I think you will have a hard time finding,I think is called a dashpot. I was talking about the choke side vac piece, hope I diddent miss lead you? Harv

07-30-2007, 12:29 PM	#4 (permalink)
dynamic88 Senior Member Join Date: Oct 2006 Posts: 160	no its the dash pot and im having a hard time finding one. ive been told that it keeps the pedal from coming back to fast. i dont know if a guy could rig up something different or not. chris

07-30-2007, 02:01 PM	#6 (permalink)
dynamic88 Senior Member Join Date: Oct 2006 Posts: 160	joe its a 425 rockchester 2 barrel

07-30-2007, 05:39 PM	#8 (permalink)
dynamic88 Senior Member Join Date: Oct 2006 Posts: 160	i started calling companys out of the olds section of hemmings. i found a company in washington state that deals in nos and repop for cars and they had some of the dash pots. original gm was 72.00 and a remanufactured one was 20.00, so i took the 20.00 dollar one and its on its way. ive checked alot of places and thought i was going to be out of luck, but i guess not. chris whats a good parts number book to get for this 65 olds dynamic 88. i need something that has a break down with gm numbers so i can find parts a little easier. thanks chris