Moparts
Holley carb won't idle. NEED HELP!
Posted By: 70Duster360
Holley carb won't idle. NEED HELP! - 01/21/09 03:05 PM
First, my combo.
360 based 408". 9.9:1 comp.
EQ magnum heads w/2.02 int.
Hughes hyd roller; 236/242 @ .050, .521/.525 w/1.6 rockers, 107 LSA installed at 104.
Air Gap intake and 1 5/8" headers.
Now my problem. When I first put this thing together I had an Edelbrock 600 I used to get it running. I got a used Holley Street Avenger 770. I took it apart, cleaned it and put in new gaskets. I did not see anything amiss but I'm no Holley expert. Well this thing just will not idle. I have to keep the throttle open to keep it running. I did not see any fuel out of the boosters when trying to let it idle only when opening it up. Ideas? Please help. By the way I'm using the Edelbrock now which dosn't idle great but it is drivable.
Posted By: MR_P_BODY
Re: Holley carb won't idle. NEED HELP! - 01/21/09 03:11 PM
Pull the idle mixture screws and blow air thru the
holes to see if they're open, useing a air nozzle
Posted By: Quicktree
Re: Holley carb won't idle. NEED HELP! - 01/21/09 03:35 PM
first thing you need to do is make sure all of your ignition/timing is right before you go messing with the carb.
Posted By: 70Duster360
Re: Holley carb won't idle. NEED HELP! - 01/21/09 05:00 PM
Mr PBODY, all passages were clear.
Quicktree, Initial is at 18 and total is 34. Zero on balancer was checked after degreeing cam. Known good timing light. Using FBO ignition. Parts store control box for now as the FBO box went kaput after a few miles. No difference between the two noticed. Thanks for the help so far!
By the way it has 69 jets in the front and 74 in the back.
Posted By: Quicktree
Re: Holley carb won't idle. NEED HELP! - 01/21/09 05:35 PM
not real up on the avenger, my advice is sell it and get you a 750dp if your going to be racing.
Posted By: aarcuda
Re: Holley carb won't idle. NEED HELP! - 01/21/09 05:39 PM
whats the lowest rpm it will idle at?
How far open are the throttle plates at that idle? How much of the idle slot is exposed?
Posted By: MR_P_BODY
Re: Holley carb won't idle. NEED HELP! - 01/21/09 05:40 PM
Quote:
Mr PBODY, all passages were clear.
Quicktree, Initial is at 18 and total is 34. Zero on balancer was checked after degreeing cam. Known good timing light. Using FBO ignition. Parts store control box for now as the FBO box went kaput after a few miles. No difference between the two noticed. Thanks for the help so far!
By the way it has 69 jets in the front and 74 in the back.
And your sure you put the metering block gaskets
on in the right direction, if I remember right if
they are on backwards they closed a port off and it
might be the idle port(but I cant remember what it did)
Posted By: 70Duster360
Re: Holley carb won't idle. NEED HELP! - 01/21/09 06:30 PM
aarcuda, the throttle plates were set so the idle slots were square but the throttle had to be held open well beyond that for it to run. Also this is now my daily driver(using the Edelbrock), although if I can get everything right I'd love to take it to the track.
Mr P BODY, I was sure I put the new gaskets right but with me, anything is poss.
I will recheck that.
Posted By: 70AARcuda
Re: Holley carb won't idle. NEED HELP! - 01/21/09 06:39 PM
you need to check you manifold vacuum..and adjust your power valve ..
you are probably not generating enough vacuum...that is why you have to open up the throttle blades to get it to run...
your idle mixture screws probably have no effect on the idle????
usuing the fix is to open up the secondary throttle blades a little to help air flow or drill the primary throttle blades...
as noted about a 750 double pumper with 4 corner idle would go along way to getting to idle right...
Posted By: Lil Demon
Re: Holley carb won't idle. NEED HELP! - 01/21/09 06:51 PM
I'm going to play worst case scenario here. I purchased a set of 1050 Dominators that I was told went down the track three times. These are the same model as what was currently on my car but I was getting them as part of a tunnel ram set up. On my car - we could not get the tunnel ram to idle at all without holding the throttle open - just like you. We thought there was a huge vacuum leak since the carbs had successfully gone down the track.
We could not isolate the cause. Finally I took the tunnel ram off and put my single back on and tried each carb with my single - they would not idle. My original carb idled just fine and it was the same model number with the same jets. We pulled the carbs apart multiple times and could not find any issue.
So, at the end of my rope, I sent them to Jesse Bigs and he found the problem - of the 4 metering blocks - only 1 of them was fully drilled. There is no way they ever went down a track.
If you are at the end of your rope - get the metering blocks checked.
Posted By: 70AARcuda
Re: Holley carb won't idle. NEED HELP! - 01/21/09 07:13 PM
i see where you said the holley was used?
do you know the history of this carb?
nothing worst then trying to fix a bad carb...
Posted By: cudabunch
Re: Holley carb won't idle. NEED HELP! - 01/21/09 07:38 PM
Quote:
Quote:
Mr PBODY, all passages were clear.
Quicktree, Initial is at 18 and total is 34. Zero on balancer was checked after degreeing cam. Known good timing light. Using FBO ignition. Parts store control box for now as the FBO box went kaput after a few miles. No difference between the two noticed. Thanks for the help so far!
By the way it has 69 jets in the front and 74 in the back.
And your sure you put the metering block gaskets
on in the right direction, if I remember right if
they are on backwards they closed a port off and it
might be the idle port(but I cant remember what it did)
Mr.P is correct as I have made this mistake.Having the gasket the wrong way will not let it idle and this was on a 950 Holley
Posted By: Sinitro
Re: Holley carb won't idle. NEED HELP! - 01/21/09 07:42 PM
A couple of issues..
1. Power valve, the 770 AV comes with a #65. If your vacuum is low due to cam timing, most likely will need to drop this down to a #45 or #35.
2. The squirters used in the 770 AV are smaller than those in the 650 AV, we have found that we had to take this up about 3 steps.
Also once you get things dialed in closer, most likely you will need to put a liter spring in for the secondaries. Or you may want to consider Qwik Technology adjustable diaphram for the secondaries dial it rite in.
Hope that helps...
Posted By: 70Duster360
Re: Holley carb won't idle. NEED HELP! - 01/22/09 12:14 AM
Vacuum is 13" - 14". I'm going to pull it apart and check gaskets in the morning.
Posted By: Blown61
Re: Holley carb won't idle. NEED HELP! - 01/22/09 03:33 AM
Quote:
A couple of issues..
1. Power valve, the 770 AV comes with a #65. If your vacuum is low due to cam timing, most likely will need to drop this down to a #45 or #35.
2. The squirters used in the 770 AV are smaller than those in the 650 AV, we have found that we had to take this up about 3 steps.
Also once you get things dialed in closer, most likely you will need to put a liter spring in for the secondaries. Or you may want to consider Qwik Technology adjustable diaphram for the secondaries dial it rite in.
Hope that helps...
Power valve and squirters have nothing to do with idle. Do your self a favor and go to the holley web site, lots of info and pics.
Here ya go.http://www.holley.com/TechService/Library.asp
Posted By: Lil Demon
Re: Holley carb won't idle. NEED HELP! - 01/22/09 05:04 AM
I still say you had better get the metering blocks checked. DAMHIK
Posted By: Sinitro
Re: Holley carb won't idle. NEED HELP! - 01/22/09 06:50 AM
Quote:
Quote:
A couple of issues..
1. Power valve, the 770 AV comes with a #65. If your vacuum is low due to cam timing, most likely will need to drop this down to a #45 or #35.
2. The squirters used in the 770 AV are smaller than those in the 650 AV, we have found that we had to take this up about 3 steps.
Also once you get things dialed in closer, most likely you will need to put a liter spring in for the secondaries. Or you may want to consider Qwik Technology adjustable diaphram for the secondaries dial it rite in.
Hope that helps...
Power valve and squirters have nothing to do with idle. Do your self a favor and go to the holley web site, lots of info and pics.
Do you understand the basics for the power valve operation.. 
Power valve tuning considerations require that the power valve should only open at wide open throttle not at idle..
Here the key is to ensure that idle vacuum does not drop below the power valve opening point.
For example..
Eratic, rough idle and over-rich condition is caused by an 8.0 idle vacuum and a power valve rated 10.5 inches of manifold vacuum. Note that a big cam w/overlap can/will drop the idle vacuum down below 8 inches.
Next Holley question please... 
Posted By: Andrewh
Re: Holley carb won't idle. NEED HELP! - 01/22/09 03:57 PM
It isn't if the gaskets are in wrong, but did you put the right ones in.
The holley kits are for multiple carbs, and if you put the wrong set in, it blocks off the idle circuit.
Been there done that. One of the gaskets at the metering block did not come out in one piece for me so I guessed, and chose poorly.
Posted By: Quicktree
Re: Holley carb won't idle. NEED HELP! - 01/22/09 04:48 PM
check fuel pressure and bowl height. look down the carb and see if fuel is running while at idle.
Posted By: AndyF
Re: Holley carb won't idle. NEED HELP! - 01/22/09 04:54 PM
If the carb is adjusted properly then the power valve doesn't have any effect on the idle circuit. It doesn't matter if it is open or not at idle as long as the throttle blades are in the right spot. BUT, having the wrong power valve in there can mess up the carb in other ways so he should of course have the correct one in there.
It sound to me like the idle circuit isn't working right for some reason. It could be as simple as the throttle blades open too much or it could be something like a blocked passage. Hard to trouble shoot over the internet either way.
Posted By: MR_P_BODY
Re: Holley carb won't idle. NEED HELP! - 01/22/09 05:23 PM
Hard to trouble shoot over the internet either way.
Yep..... you gotta back that car up to the key board
and let me hear it.... LOL. A shop I use to work at
years ago(before cell phones)we did driveablity on
Mopars. Sitting around after work and having a couple
of beers we had a customer call and wanted us to
diagnoise the car over the phone(of course without
paying for our services).... we told him to back it
up the the phone so we could figure it out... he wasnt
real happy 
Posted By: radar
Re: Holley carb won't idle. NEED HELP! - 01/22/09 05:24 PM
Howdy
a lot of more knowledgeable people than me have chimed in, but I just went through a similar problem with my 408. It turned out that the vac. advance(now disconnected)had a lot to do with my problem, but another thing that helped a lot with dieseling on shutdown and getting the idle happy below 1000 rpm was opening the secondary blades a touch. This is on a 750 dp, which has not only a four corner idle but also the small screw on the bottom of the carb to open the secondary. The screw has just enough adjustment to do what I needed- maxed it out and it was easy to use the regular curb idle screw to get me where I needed.
If the carb you got is a 2 corner idle maybe I'm blowing smoke atcha? I dunno but good luck, and feel free to pm me, I'm probably struggling with all the same issues as you.
Kevin in Philly
Posted By: Von
Re: Holley carb won't idle. NEED HELP! - 01/22/09 05:31 PM
Are you sure you used the correct baseplate gasket? I used the wrong baseplate gasket on a 800DP once and it acted as you describe?
Posted By: Anonymous
Re: Holley carb won't idle. NEED HELP! - 01/22/09 06:01 PM
You got a spacer under the carb? I have a plastic 4 hole spacer.Put it on upside down once so the passageways that allow the gas to dribble down from the idle circuit werent there.They were on the intake side.No idle.
Posted By: 70Duster360
Re: Holley carb won't idle. NEED HELP! - 01/22/09 06:22 PM
OK, I've pulled off the primary bowl and metering block this morning. All passages are clear. I made sure to use the same style gaskets I took off. It only has a primary side idle circuit, would adjusting the rear blades a bit make any diff? I am not opposed to drilling the primary throttle plates, but did not want to do anything that was not needed. I hope to have some time this afternoon to swap it back on and try it again.
Posted By: AndyF
Re: Holley carb won't idle. NEED HELP! - 01/22/09 06:43 PM
Quote:
Vacuum is 13" - 14". I'm going to pull it apart and check gaskets in the morning.
With that much vacuum you shouldn't have any trouble getting it to idle with the throttle blades in the correct location. I'm guessing you have some other problem with the engine. Maybe crossed up plug wires, fouled plugs, etc.
When you have a basic tuning issue like this you need to double check all the basics. Float level, vacuum leaks, firing order, etc.
Posted By: Quicktree
Re: Holley carb won't idle. NEED HELP! - 01/22/09 06:50 PM
the vac should be checked at idle in gear to get a reading for the correct PV. what ever it is the PV should be 2 less. vac is 10 PV should 8.