Rochester Quadrabog
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From: Traveling the US
Rochester Quadrabog
First I would like to start off by saying every experienced muscle car owner friend of mine told be to buy a Holley from day one. I should have listened.
I had my Quadrajet rebuilt by an experienced reputable shop. I have been dealing with bogging since I put my vette back together.
When I go WOT quickly (floor it), the car bogs badly. Well, I was told to check and see if the accelerator pump was touching the air cleaner. It's not. Timing is set to 36 degrees full advance. 16 in vacuum at idle (268H cam).
I did this test yesterday with the hood up.
Air cleaner on, pull the throttle wide open (fast) - bog then accelerate
Air cleaner top off, bottom still on - bog then accelerate
Air cleaner totally removed - no problem, sounds good
put the bottom air cleaner assembly within one inch of the carb - bog
So then i moved my hand around the carb and pulled the throttle. It seems when I restrict the flow of air around the front passenger side of the carb, it bogs.
At this point I would like to remove the Quadrabog and throw it as far as I can down a gravel road.
I was told a Holley 650 double pumper would be good with my setup.
I had my Quadrajet rebuilt by an experienced reputable shop. I have been dealing with bogging since I put my vette back together.
When I go WOT quickly (floor it), the car bogs badly. Well, I was told to check and see if the accelerator pump was touching the air cleaner. It's not. Timing is set to 36 degrees full advance. 16 in vacuum at idle (268H cam).
I did this test yesterday with the hood up.
Air cleaner on, pull the throttle wide open (fast) - bog then accelerate
Air cleaner top off, bottom still on - bog then accelerate
Air cleaner totally removed - no problem, sounds good
put the bottom air cleaner assembly within one inch of the carb - bog
So then i moved my hand around the carb and pulled the throttle. It seems when I restrict the flow of air around the front passenger side of the carb, it bogs.
At this point I would like to remove the Quadrabog and throw it as far as I can down a gravel road.
I was told a Holley 650 double pumper would be good with my setup.
Pro
Joined: Aug 2001
Posts: 605
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From: hamilton square NJ
Re: Rochester Quadrabog (Rhys)
Hey I had the same thing happen to me when I replaced my cam with a 268H. The first time I took it out with the quadrajet it bogged so bad I wanted to smack it with a hammer. Later that day I was driving and I put the petal to the floor only to have the car bog so bad it stalled. It also wouldn't start up after that and was leaking fuel on the manifold. Needless to say I threw that carb in the garbage and bought a Demon. I haven't seen that bog happen yet. :cool:
Advanced
Joined: Feb 2001
Posts: 76
Likes: 4
From: Bethel Park, PA
Re: Rochester Quadrabog (Rhys)
The same thing was happening with mine and it was driving me crazy. Turns out the fix was pretty easy. The air valve spring needed adjusted. It was set too loose and it was opening too quickly. After a little bit of trial and error it now runs great with no bog.
Melting Slicks
Joined: Nov 2000
Posts: 2,663
Likes: 3
From: Palm Harbor FL
Re: Rochester Quadrabog (Rhys)
So, that's where you went?
I know this isn't the answer to your problem, because I'm sure you'd probably rather fix the carb problem, but have you tried an open element filter? Do you think it would still do it? Could be a temporary Bubba fix. :D
I know this isn't the answer to your problem, because I'm sure you'd probably rather fix the carb problem, but have you tried an open element filter? Do you think it would still do it? Could be a temporary Bubba fix. :D
Thread Starter
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From: Traveling the US
Re: Rochester Quadrabog (JimD)
Already adjusted the airvalve spring. I thought I fixed it once, but I bet it was just a fluke of me not having the aircleaner on right.
Take a look at my tests. It is not the spring. Also, if I drive it around totally open (no top on the air cleaner) it bogs (no restriction to air flow). If I take the bottom of the air cleaner off too, it feels like I have 50 hp more!
Take a look at my tests. It is not the spring. Also, if I drive it around totally open (no top on the air cleaner) it bogs (no restriction to air flow). If I take the bottom of the air cleaner off too, it feels like I have 50 hp more!
Le Mans Master
Joined: Aug 2000
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From: Semper ubi, sub ubi
Cruise-In VI Veteran
Cruise-In VII Veteran
Re: Rochester Quadrabog (Rhys)
There isn't anything wrong with the Q-jet if it is setup right. It sounds to me like your's isn't setup right, send it to Lars and have him set it up for your car.
Thread Starter
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Joined: Dec 1999
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From: Traveling the US
Re: Rochester Quadrabog (Smokehouse69Mark2)
One more thing, when I floor it, I smell gasoline because there is some fuel leaking around the accel pump (on top).
Mark, I don't want to throw another $100 on top of my $125 and still have an old crappy carb. Don't you think a Holley would be better for $275 at this point?
Mark, I don't want to throw another $100 on top of my $125 and still have an old crappy carb. Don't you think a Holley would be better for $275 at this point?
Instructor
Joined: Jan 2000
Posts: 222
Likes: 0
From: Buenos Aires
Re: Rochester Quadrabog (Rhys)
Hey Rhys...cool down!!:mad
Believe me I know how frustrating it is when something new doesn't work, but that doesn't mean the Q-Jet is a Q-Bog.
Although it was designed with other priorities, with the right tweaks it can be made to perform as much as a Holley, with reliability as an outstanding factor, I mean once you set them up, they perform solid as a rock.
From what you describe above, it seems you have an air restriction problem and a way too rich mixture. Was the carb set up on a bench or in it's real enviroment (on top of the engine bolted to the car??) :D
I myself have a Q-Jet (edelbrock's performer rpm 850cfm) which is going into my baby later on this year.
Where are the Q-Jet supporters?
Believe me I know how frustrating it is when something new doesn't work, but that doesn't mean the Q-Jet is a Q-Bog.
Although it was designed with other priorities, with the right tweaks it can be made to perform as much as a Holley, with reliability as an outstanding factor, I mean once you set them up, they perform solid as a rock.
From what you describe above, it seems you have an air restriction problem and a way too rich mixture. Was the carb set up on a bench or in it's real enviroment (on top of the engine bolted to the car??) :D
I myself have a Q-Jet (edelbrock's performer rpm 850cfm) which is going into my baby later on this year.
Where are the Q-Jet supporters?
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Thread Starter
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Joined: Dec 1999
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From: Traveling the US
Re: Rochester Quadrabog (El Mago)
It was rebuilt and set up on the bench. I brought it back to the rebuilder months later because of this problem. They took it off the car, took it apart, re-set it up, put it back on the car and set it up and adjusted it again.
I have enough other stuff to deal with, so that is why I think I want to just get a new one and forget it. :mad
I have enough other stuff to deal with, so that is why I think I want to just get a new one and forget it. :mad
Race Director
Joined: Apr 1999
Posts: 11,520
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From: CORVETTE 77 385 C.I. TEXAS
Re: Rochester Quadrabog (El Mago)
Accel. pump is leaking & there is more than 1 setting. There is limited idle mixture adjustment & you probably can not make too rich. Which air filter & make sure something is not catching. Did you check air valve play I described before?
:cheers:
:cheers:
Thread Starter
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From: Traveling the US
Re: Rochester Quadrabog (Ganey)
Ganey, I tried this with NO filter on at all, and just set my hand over the right front area of the carb and it repeats the bog.
Yes, on the air valve, I did that exactly as Lars told me.
There is definately nothing catching because I had the air cleaner totally off. The only time it runs great is when there is nothing in the front right area of the carb restricting air flow in that area.
Yes, on the air valve, I did that exactly as Lars told me.
There is definately nothing catching because I had the air cleaner totally off. The only time it runs great is when there is nothing in the front right area of the carb restricting air flow in that area.
Thread Starter
Platinum Supporting Dealership
Joined: Dec 1999
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From: Traveling the US
Re: Rochester Quadrabog (Ganey)
Have not had that problem. Adjust mixture start by turning all the way out i.e. until rpm or vac. stops rising.
Melting Slicks
Joined: Nov 2000
Posts: 2,663
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From: Palm Harbor FL
Re: Rochester Quadrabog (Rhys)
Sounds like you want a reason to get a Holley. :D If you're going to dump it, let me know. Mine is in pretty bad shape, and I might be willing to give it a try.
Instructor
Joined: Dec 2000
Posts: 192
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From: Blythewood, SC
Re: Rochester Quadrabog (vettepowA)
I have offered repeatedly to trade two quadracraps for one Holley and have never been accepted. That should tell you what absolute pieces of $H!T they are. I have only heard of one quadra$hit that worked, and I don't want to jinx it by looking at it or mentioning the owner's name.
Buy a Holly or Edelbrock and use that quadrajunk as a hammer or wheel chock. :cool:
Buy a Holly or Edelbrock and use that quadrajunk as a hammer or wheel chock. :cool:
Pro
Joined: Jan 2001
Posts: 594
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From: St. Charles, MO
Re: Rochester Quadrabog (Project76)
Some of these comments are a little like saying that a '58 fuelie is a complete piece of junk just because I cant figure out how to tune it. Why is it that there are 12 second cars running Q-jets, yet people with 15 second cars think the Q-jet is their problem? Sure, there may be better carbs out there, but no matter which carb you have, if it aint tuned right, it will run like crap, and that's not the carbs problem. As many have stated, I'll take a few of these sent my way too if your throwing them out.
My .02
:D :chevy :D :chevy :D :chevy :D
My .02
:D :chevy :D :chevy :D :chevy :D