383 Wont Idle with new to me 800cfm DP. Idles and runs ok with Edelbrock/AFB

-
3

340dartley

Well-Known Member
Joined
Feb 4, 2007
Messages
519
Reaction score
170
i have a fresh 383 bored .060 over. New old stock direct connection 11.5 to 1 forged pistons, Mopar 292 .509 cam. Holley street dominator intake manifold. 906 heads with bowl clean up and port matching. No real porting though. When the motor was completed I did not have a carb for it so I dropped an old 600cfm Edelbrock carb I had sitting on the shelf. It starts and runs well. Has a healthy sounding lopey idle. Decent drivability but really giving up a lot on WOT power with the small size.
I picked up an 800 CFM DP yesterday used but very clean. They said it had a kit put in it. I did take it apart and look and it has fresh seals and gaskets and is very clean inside and out. Front jets are 70s. I was unable to make out what the rear jets were but I believe 70s also. I put it on and started the car up. It would not idle at all. I could turn up the idle to approx 1800 and it would hold it. I slower turn the idle screw back until it gets to the idle circuit and it dies. I have adjusted the idle mixture screws out up to 4 turns and no change. I am thinking maybe power valve is set for too high of vacuole and maybe my 7 to 8 inches of vac is causing it to dump. I did not see any vacuum leaks. I have since removed it and put the Edelbrock back on and it is back to running normal. Is this a case where drilling holes in the throttle plates is in order? Thanks for the replies.
 
You may disagree with this, but I think it is time for a NEW Edelbrock 750 (+/-) Carb. I would never buy a used carb that was rebuilt unless it was built by a professional who made a living by rebuilding carbs. I realize there are a LOT of people out there who are quite good at rebuilding carbs, but for me, It is new or professionally rebuilt. That is my $0.02 worth.
 
The 800 DP is pretty big for a 383, IMO.
 
harrisonm said:
You may disagree with this, but I think it is time for a NEW Edelbrock 750 (+/-) Carb. I would never buy a used carb that was rebuilt unless it was built by a professional who made a living by rebuilding carbs. I realize there are a LOT of people out there who are quite good at rebuilding carbs, but for me, It is new or professionally rebuilt. That is my $0.02 worth.
Click to expand...
I don’t disagree. I don’t have a problem rebuilding a carb. I am more wondering if there is something specific to Holley such as the power valve that makes it not like this engine. I have a 750 DP on my 340 and runs well, however someone before me drilled small holes in the primary throttle plates. Was wondering if this is a fix for similar issue. 340 has a MOPAR 508 292 cam and runs 11.90s.
 
I got to laugh "Holly people" LOL I think either carb works well if it's in good condition. I personally like Edelbrock's cuz they seem less finicky.
now I thought I was pretty damn good at those 1406 s and have a couple myself. I've taken them down to nothing and put them back together with kits and have had great results. But this last 1406 that I had same problem, ran fine but wouldn't idle said the last person that I owned it. I went out bought a brand new rebuild kit and dipped in a vat of carburetor cleaner. Then cleaned every orifice out with spray carburetor cleaner. Then assembled it and it was shining like a brand new penny. Put it on my car and it ran fine like before but could not hold an idle. I sold it at the last swap meet for $60 with the receipt for the $50 rebuild kit and put it out of my life...
 
j par said:
I got to laugh "Holly people" LOL I think either carb works well if it's in good condition. I personally like Edelbrock's cuz they seem less finicky.
now I thought I was pretty damn good at those 1406 s and have a couple myself. I've taken them down to nothing and put them back together with kits and have had great results. But this last 1406 that I had same problem, ran fine but wouldn't idle said the last person that I owned it. I went out but a brand new rebuild kit and dipped in a vat of carburetor cleaner. Then cleaned every orifice out with spray carburetor cleaner. Then assembled it and it was shining like a brand new penny. Put it on my car and it ran fine like before but could not hold an idle. I sold it at the last swap meet for $60 with the receipt for the $50 rebuild kit and put it out of my life...
Click to expand...
Well the good thing on this 800 is I am not totally committed to it. The guy I got from basically told me to try it out and see if I like it. I was in the market for a carb and price is right. He said it came off his jet boat and was removed for EFI. Obviously I won’t be drilling anything unless I am sure I will use it. I did read about adjusting the secondary stop screw to creat an air bleed so I can lower my primaries into the idle circuit.
 
Sounds like you have a vacuum leak to me, look it over good. People that don't like Holley's can't tune them, Keep the Holley and figure out what the problem is. Take a piece of vacuum hose and stick it in your ear and take the other end and go around the base and if there is leak you will hear it. The power valve is probably open at idle so figure out what you have and change it to what you need.
 
I wouldn't have a problem running a 800 on a 383, try a 4.5 power valve if you have 8" vacuum at idle, that seem low for that cam that's why I think you have a vacuum leak, get you throttle plates set right, about 1.5 turns from closed on the front and it should idle if every thing is right.
 
I wouldn't be afraid to run that 800 on my 367 manual trans. I currently run a 750DP.And I have run that 292/108 cam in my 367 with the same 750DP, with the same 10.5 PV; and idling at 750 and less.
But I wouldn't run it with anything less than a 10/1 starter gear (manual trans), or a 9/1 with an automatic and a 2500TC, AND as much compression as your gas will support. Without the compression you will need more TC and perhaps a deeper rear gear.
But back on topic;
IMO;You have either
A) a serious vacuum leak or
B) the carb is pissing gas down the barrels, or
C) the low-speed circuit is not working

As to A) this should be an easy find.
As to B) this is even easier to find
Only C) will be tricky. Start by advancing the timing to ~18* at 800 if she'll go there. If not, then just keep advancing until you can start backing off the idle speedscrew.
That cam likes a lot of idle bypass air. So take the carb off and close the primaries all the way, then make sure the secondaries are closed up tight but not sticking. Next crack the secondaries just a little with that stoopid little screw that they put in there that you can only access with the carb off; I think it's called the secondary cracking screw. Myself, I take it outta there and turn it around and install it downside up. Now you can adjust it from the top. Of course the engine will have to be shut off, and the secondaries WOT,to do it,lol.
Anyway; after the secondaries are cracked maybe 1.5 turns, then open the primaries until the transfers show square to a little taller than wide. Then readjust the mixture screws to 1 turn out from lightly seated. Finally make sure you got the right basegasket and that it's in good shape, and don't put it on a spreadbore intake.Well you can; with the right adapter and the right gaskets that properly seal everywhere.Good luck with that.
Now; after the carb is installed DO NOT TOUCH the speedscrew. You will be setting the idlespeed with timing and idle-bypass air, namely the secondary cracking screw.With the extra timing it should idle. If it doesn't, then go back to the ABCs. (Edit: later once everything works, we can revisit the throttle openings)
Course it goes without saying that the fuel levels have to be correct and stable,and the gas is fresh; right?
If you still can't bring the idlespeed into line, I suspect the lowspeed circuit is not working properly, that is to say the transfers are not flowing.(Edit: and/or Idle discharge ports.) You will have to take the front bowl off and verify the right gasket was installed, then you may have to go thru that circuit. While the bowl is off, you can check for a ruptured diaphragm in the PV.
That's all I got for now.(Edit: make sure the PCV is installed and working, and that the breather works in both directions)
Except; at idle; the carb don't care what jets are in it, or if there even are jets in the holes. BUT it is very sensitive to fuel level and stability. And of course; the valves have to actually close, for something like; the math says 110* ; but in reality could be like 90/95*. Closed and not leaking.
Good luck.
 
Last edited:
AJ/FormS said:
I wouldn't be afraid to run that 800 on my 367. I currently run a 750DP.
And I have run that 292/108 cam in my 367 with the same 750DP, with the same 10.5 PV; and idling at 750 and less.
You have either
A) a serious vacuum leak or
B) the carb is pissing gas down the barrels, or
C) the low-speed circuit is not working

As to A) this should be an easy find.
As to B) this is even easier to find
Only C) will be tricky. Start by advancing the timing to ~18* at 800 if she'll go there. If not, then just keep advancing until you can start backing off the idle speedscrew.
That cam likes a lot of idle bypass air. So take the carb off and close the primaries all the way, then make sure the secondaries are closed up tight but not sticking. Next crack the secondaries just a little with that stoopid little screw that they put in there that you can only access with the carb off; I think it's called the secondary cracking screw. Myself, I take it outta there and turn it around and install it downside up. Now you can adjust it from the top. Of course the engine will have to be shut off, and the secondaries WOT,to do it,lol.
Anyway; after the secondaries are cracked maybe 1.5 turns, then open the primaries until the transfers show square to a little taller than wide. Then readjust the mixture screws to 1 turn out from lightly seated. Finally make sure you got the right basegasket and that it's in good shape, and don't put it on a spreadbore intake.Well you can with the right adapter and the right gaskets that properly seal everywhere.
Now; after the carb is installed DO NOT TOUCH the speedscrew. You will be setting the idlespeed with timing and idle-bypass air, namely the secondary cracking screw.With the extra timing it should idle. If it doesn't, then go back to the ABCs
Course it goes without saying that the fuel levels have to be correct and stable,and the gas is fresh; right?
If you still can't bring the idlespeed into line, I suspect the lowspeed circuit is not working properly, that is to say the transfers are not flowing. You will have to take the front bowl off and verify the right gasket was installed, then you may have to go thru that circuit. While the bowl is off, you can check for a ruptured diaphragm in the PV.
That's all I got for now.
Good luck.
Click to expand...
Yes gas is good. All very good information. I will check it that rout when I get back to it tomorrow. I will throw out that the Holley street dominator intake accepts a spread bore as well as a standard bore. I am using the same style gasket for both the Edelbrock and Holley carburetors. I do not see any place where they would leak.
 
I disagree. It could be the carb. Some have weird calibration. Especially in that 'size' range. What's the list and revision number ?
If you don't want to dig into it, then just return it. Recalibration will involve more than jets.

It's not the secondary jets, and it shouldn't be the primary jets and PV unless the calibration is really messed up.

The idle feed restrictions should be around .030" diameter. Main jets around twice that. That's 4 times the area. The small restriction should be the only thing that matters at idle. When your kitchen faucet only flows a few gallons per minute, it's because the faucet's restriction, not a restriction at the meter's valve. As proof,
go open the outside hose valve and it will flow alot more.

Just to be sure its fixed calibration issues, go over everything.
1. Set the float levels.
2. Set the primary throttle blades so roughly .020 - .030" of the transfer slots show.
3. engine running recheck fuel level.
4. Warmed up, see if small adjustments of the throttle position and what effect adjustments of idle mix screws have.
If unsatisfactory, that's it. It's not your carb. Give it back.
 
340dartley said:
I slower turn the idle screw back until it gets to the idle circuit and it dies. I have adjusted the idle mixture screws out up to 4 turns and no change. I am thinking maybe power valve is set for too high of vacuole and maybe my 7 to 8 inches of vac is causing it to dump. I did not see any vacuum leaks. I have since removed it and put the Edelbrock back on and it is back to running normal. Is this a case where drilling holes in the throttle plates is in order? Thanks for the replies.
Click to expand...
I slower turn the idle screw back until it gets to the idle circuit and it dies.
It was on the 'idle circuit' the whole time. (At 1800 rpm really unlikely the boosters started up. But you can look. ) The 'idle circuit' supplies fuel above idle. The idle ports are only a branch of that circuit.
I have adjusted the idle mixture screws out up to 4 turns and no change
Not surprising they lose effect above 2.5 turns out or so. What happened when you ran the screws in?
If you want to give it another try, set the transfer slot as mentioned above. WRITE DOWN how many turns of the idle stop screw it takes to reveal .020. .030 and .040 of the transfer slot.
When on the engine, it should be no more than .040 once its warmed up.
What's the initial timing at? 800 rpm? 1000 rpm? 1200 rpm, 1800 rpm? Within reason you can pickup some rpm by increasing the timing. Going to guess it will want at least 16* and will probably like 18* initial better, maybe as much as 20.
Is this a case where drilling holes in the throttle plates is in order?
Yes. But it seems too far off and too little info to jump to concluding that's what is needed.
 
Mattax said:
I slower turn the idle screw back until it gets to the idle circuit and it dies.
It was on the 'idle circuit' the whole time. (At 1800 rpm really unlikely the boosters started up. But you can look. ) The 'idle circuit' supplies fuel above idle. The idle ports are only a branch of that circuit.
I have adjusted the idle mixture screws out up to 4 turns and no change
Not surprising they lose effect above 2.5 turns out or so. What happened when you ran the screws in?
If you want to give it another try, set the transfer slot as mentioned above. WRITE DOWN how many turns of the idle stop screw it takes to reveal .020. .030 and .040 of the transfer slot.
When on the engine, it should be no more than .040 once its warmed up.
What's the initial timing at? 800 rpm? 1000 rpm? 1200 rpm, 1800 rpm? Within reason you can pickup some rpm by increasing the timing. Going to guess it will want at least 16* and will probably like 18* initial better, maybe as much as 20.
Is this a case where drilling holes in the throttle plates is in order?
Yes. But it seems too far off and too little info to jump to concluding that's what is needed.
Click to expand...
Maybe I need to try and describe the Symptom a little better or at least with more detail. When I initially installed the carburetor, it would not idle at all. I could keep it running by holding the throttle open. Using the idle speed screw I turned it in until I was able to release the throttle without it stalling. This was at a about 1800 rpm. I then screwed the idle mixture screws all the way in and then backed them both out 2 turns. I then tried lowering the idle speed and adjusting the mixture screws in and out. Giving it a bit of throttle input when ever it would start to die. The mixture screws had little to no effect regardless of position. At one point I think I had it idle down to 1200 rpm but one goose of the throttle and it would not idle again.
As far as initial timing, I will have to recheck that. I set it at 33 degree total timing at 2000 rpm. I did not suspect a timing issue as it runs normal with the old carburetor. For the record the distributor is an old Mallory Dual point with no vacuum advance.
 
increasing the initial timing will cure most carburetor problems....that camshaft will like alot of initial timing....plus a BB total timing should be up around 38 degrees...
 
340dartley said:
Maybe I need to try and describe the Symptom a little better or at least with more detail. When I initially installed the carburetor, it would not idle at all. I could keep it running by holding the throttle open. Using the idle speed screw I turned it in until I was able to release the throttle without it stalling. This was at a about 1800 rpm.
Click to expand...
A carb that is runs nice fully warmed up, will need to be held open when cold. Running the screw in to get it warmed up is common procedure.
What we don't know is if this is really the case, and the eddy you had on it was too rich.
However with that cam, its going to want richer carb feeding cold or hot.

340dartley said:
I then screwed the idle mixture screws all the way in and then backed them both out 2 turns.
Click to expand...
This must be because the idle port isn't restricting the fuel. Throttles are still too far open at idle.

340dartley said:
As far as initial timing, I will have to recheck that. I set it at 33 degree total timing at 2000 rpm. I did not suspect a timing issue as it runs normal with the old carburetor. For the record the distributor is an old Mallory Dual point with no vacuum advance.
Click to expand...
That's a logical conclusion. Not really knowing why the old carb did well or what the timing is at raises the question. Timing and fueling go hand in glove.
With no vacuum advance, the 33 at 2000 might be fine. or maybe it could use a little more.
Definately check timing at the low rpms, and also at 3000 rpm. Depending on the springs, it might still advance a few more degrees as the rpms climb. That would be OK.
 
Mattax said:
A carb that is runs nice fully warmed up, will need to be held open when cold. Running the screw in to get it warmed up is common procedure.
What we don't know is if this is really the case, and the eddy you had on it was too rich.
However with that cam, its going to want richer carb feeding cold or hot.


This must be because the idle port isn't restricting the fuel. Throttles are still too far open at idle.


That's a logical conclusion. Not really knowing why the old carb did well or what the timing is at raises the question. Timing and fueling go hand in glove.
With no vacuum advance, the 33 at 2000 might be fine. or maybe it could use a little more.
Definately check timing at the low rpms, and also at 3000 rpm. Depending on the springs, it might still advance a few more degrees as the rpms climb. That would be OK.
Click to expand...
Timing on this distributor is all in by 2000. After experimenting with this carb the other day, the Edelbrock was put back on and it went back to running smooth. I am a little limited on what I can run on total advance because of high compression ratio and pump gas. I run av gas or an av gas pump gas blend when I plan to race it or do spirited driving. Currently it is on pump gas 91 octane is best at pump I can buy here in California.
 
Didn't read all the answers... some are lengthy. My 2 cents, you have a vacuum leak. Could be something minor, or could be a warped body/metering body.
 
318willrun said:
Didn't read all the answers... some are lengthy. My 2 cents, you have a vacuum leak. Could be something minor, or could be a warped body/metering body.
Click to expand...
You may be correct. If there is a leak it is internal in carburetor. I am going to go through the carburetor to make sure everything is ok and nothing obvious was messed up.
 
Any situation where the idle screws are ineffective,the idle screw is turned in too far,uncovering too much of the transfer ports.
By settiing idle mixture screws at 2 to 2-1/2 turns and adjusting timing to get idle where you want it then tune from there.
Just had one a week ago that was terrible rich at idle,mixture screws were out 4 plus turns.
Backing off throttle stop screw and adjusting timing as i went i managed to get it to where it would idle nice,and idle mixture made positive changes.
I’m no expert,but i stick with what works. Holleys are great once you get an understanding of them.
I prefer the eddy’s myself.
 
340dartley said:
Timing on this distributor is all in by 2000. After experimenting with this carb the other day, the Edelbrock was put back on and it went back to running smooth. I am a little limited on what I can run on total advance because of high compression ratio and pump gas. I run av gas or an av gas pump gas blend when I plan to race it or do spirited driving. Currently it is on pump gas 91 octane is best at pump I can buy here in California.
Click to expand...

Waitaminute.
If this is a track-car, ignore the following;
How much cylinder pressure is this engine making?
With a true 10.5 Scr and that cam's (if a 108LSA cam) Ica of 70* installed at 104*, then yes; you have too much pressure for iron heads. If a streeter I would knock it down and fix that. But just putting 10.5 pistons in the block, doesn't automatically make it a 10.5 engine. Ima guessing you know that.
But if a streeter, check this out. This has nothing to do with your problem, just an observation.
I see your AV gas solution as maybe a band-aid for the 33* at 2000 rpm. If this is a streeter with anything but a very hi-stall TC, there is no reason to run that much low-rpm advance.
I have run that 292/292/108 in my 11.3Scr Eddie headed 367 with as little as 5* initial timing, but mostly with 14* initial, and with 28*@2800, and 32@ 3400. That's all on the same curve. And with the Vcan modded to 22* maximum, the total Part-Throttle timing available was; 50*@2800/54*@3400. And it was a tire-fryer on the power curve. Tuned like this it has always run on 87E10 all the time, and at up to and even a tic over 185 psi cylinder pressure.
As a streeter;You gotta have a working Vcan..... you just gotta.
As a streeter, ask yourself how often do you go thru the zone of STALL to 3400 at WOT, compared to how much time you spend at part throttle. Then ask yourself why you have a race timing-curve and a no-Vcan distributor in your streeter. With say a 2800TC, then 2800 to 3400 is a one-time deal from around 23 mph to 28mph, surely your 388 cuber can pull you thru that zone with less timing..... and therefore with less antiknock.
Right now,
at 33* all-in by 2000 rpm, and no Vcan;
below about 3600 rpm, your timing is right just about exactly at one rpm and load setting, and Ima thinking it would be at very light acceleration around the stall-speed.And again at maybe 3200WOT....At over 3600 it's never right.
And neither is it right at idle. And this is very important.
With 33*at 2000, and maybe 10* in the mechanical, this makes the idle timing to be around 23*, am I close? But it won't hold still because it wants to be advancing all the time with those very light springs in there. If you can't get the idle down under the start-point of the timing curve, then you will never have a stable idle-speed.
But it gets worse, with the timing so far advanced then when you try to idle it down, you will be closing the throttle to below the start-point of the transfers, shutting them off, and then it stalls.But if some transfer exposure still exists; then,now with the low vacuum of that cam the transfers may want to dry up. So when you get to opening the throttle, it takes time for the transfers to wake up, and so you get a big old stumble. To cure that you start fudging the pumpshot and fuel level, and on and on it goes. While the cure is staring right at you; namely a lack of transfer slot exposure, mostly caused by the excessive idle-timing.
So check it out.
IMO, it runs pretty good (with the Edelbrock carb) because it's a 388 cuber often running with extra anti-knock.
Imagine how it could run with the proper timing at least some of the time.
Please don't hate me..... I'm just trying to help
 
Last edited:
Ok update. I
AJ/FormS said:
Waitaminute.
If this is a track-car, ignore the following;
How much cylinder pressure is this engine making?
With a true 10.5 Scr and that cam's (if a 108LSA cam) Ica of 70* installed at 104*, then yes; you have too much pressure for iron heads. If a streeter I would knock it down and fix that. But just putting 10.5 pistons in the block, doesn't automatically make it a 10.5 engine. Ima guessing you know that.
But if a streeter, check this out. This has nothing to do with your problem, just an observation.
I see your AV gas solution as maybe a band-aid for the 33* at 2000 rpm. If this is a streeter with anything but a very hi-stall TC, there is no reason to run that much low-rpm advance.
I have run that 292/292/108 in my 11.3Scr Eddie headed 367 with as little as 5* initial timing, but mostly with 14* initial, and with 28*@2800, and 32@ 3400. That's all on the same curve. And with the Vcan modded to 22* maximum, the total Part-Throttle timing available was; 50*@2800/54*@3400. And it was a tire-fryer on the power curve.
As a streeter;You gotta have a working Vcan..... you just gotta.
As a streeter, ask yourself how often do you go thru the zone of STALL to 3400 at WOT, compared to how much time you spend at part throttle. Then ask yourself why you have a race timing-curve and a no-Vcan distributor in your streeter. With say a 2800TC, then 2800 to 3400 is a one-time deal from around 23 mph to 28mph, surely your 388 cuber can pull you thru that zone with less timing..... and therefore with less antiknock.
Right now,
at 33* all-in by 2000 rpm, and no Vcan;
below about 3600 rpm, your timing is right just about exactly at one rpm and load setting, and Ima thinking it would be at very light acceleration around the stall-speed.
At over 3600 it's never right.
And neither is it right at idle. And this is very important.
With 33*at 2000, and maybe 10* in the mechanical, this makes the idle timing to be around 23*, am I close? But it won't hold still because it wants to be advancing all the time with those very light springs in there. If you can't get the idle down under the start-point of the timing curve, then you will never have a stable idle-speed.
But it gets worse, with the timing so far advanced then when you try to idle it down, you will be closing the throttle to below the start-point of the transfers, shutting them off, and then it stalls.But if some transfer exposure still exists; then,now with the low vacuum of that cam the transfers may dry up. So when you get to opening the throttle, it takes time for the transfers to wake up, and so you get a big old stumble. To cure that you start fudging the pumpshot and fuel level, and on and on it goes. While the cure is staring right at you; namely a lack of transfer slot exposure, mostly caused by the excessive idle-timing.
So check it out.
IMO, it runs pretty good because it's a 388 cuber often running with extra anti-knock.
Imagine how it could run with the proper timing at least some of the time.
Please don't hate me..... I'm just trying to help
Click to expand...
Technically it is a street car I suppose. It gets driven occasionally around my small town and to the Friday night cruise which basically turns into a burnout festival. It really wants to be a track car though if that makes sense. It it does have a true 11.5 to 1. Zero deck height .060 motor. Here is my problem with building the motor and this is my own flaw. I am on an extreme tight budget. I built the motor over a 10 year span and with craigslist and swap meet finds. Here is a summery of the motor. It was bored .060 over, zero deck height on the pistons. Direct Connection new in box 11.5 to 1 forged pistons. Skirt clearance at .010 as these are the old school pistons that grow a bunch with temp. The motor has 1 sleeve for what it is worth. ARP main bolts. ARP Rod bolts. Rods resized. Crank original steel crank turned .020 under. Balanced rotating assembly. Heads are mostly stock 906 castings. Hoping to upgrade later. Valve train stock. Cam is mopar performance 292 509 degrees and installed strait up. Double roller timing chain, mopar windage tray, high volume low pressure oil pump. The car is not an A body (forgive me but best knowledge seems to be here and I do have 2 other A bodies). It is in a 68 rust bucket Sport Satellite that I have owned since just after high school (1992) 727 torque flight with reverse manual valve body. Unknown brand 3000 rpm stall converter (10 inch). 3.90 to 1 rear gears. It is a big fun car to drive. Hopes to be a mid 12 second car when dialed in.
 
Last edited:
Ok update on the carburetor. I went through the Holley again and didn’t really find anything off. Main jets are 70 in the front and 85 in the back. Power valve is a 6.5. I installed a 1 inch carb spacer for 3 reasons 1 I wanted to experiment with more plenum volume, 2 I needed to gain some clearance from the choke well on the intake because it was causing the secondary linkage to not open more than half way, and 3 I was buying. New carb gaskets anyway so used this a way to get them.
I did flip the secondary throttle stop screw so it can be accessed from the top (great tip). Reinstalled carb and started vehicle. Same exact issue as before. Only idle at 1800 rpm. Lowering idle while adjusting mixture screw had no effect. I then turned the secondary throttle screw out 1 turn and restarted engine. I was now able to lower idle down to normal idle speed of 800. I tried adjusting idle mixture. Idle mixture screws have no effect. I can turn them all the way in or all the way out. engine still sits and idle sand wont stall. I am thinking it is getting fuel from either a leaking or incorrect for my combo power valve. I feel like me adjusting the secondary throttle stop is a bandaid covering up another issue. On a good note the car runs really well power wise with the 800 on it.
 
You said you had 6 " vacuum at idle, a 6.5 PV will be open at idle dumping fuel.
 
You must log in or register to reply here.
-

Back
Top