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Discussion Starter #1
I just put a different motor in my car and it has been in for about a month now. While it was cold outside the car ran great. Now all of the sudden the car will not idle. I checked my floats and both were up to high so I have them just below the site plug and was able to run the car with the screw out and gas stayed in. If I turn the idle up it will stay on but as soon as I drop it down to were it needs to be the car dies. I have a holley 4 barrel carb with a edelbrock intake and a pretty good size cam if any of that matters. Thanks for any help or info.
 

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holley model ?
 

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Should dribble out of site hole iirc. Gently turn idle mixture screws all the way in. Back out 1.5 turns. That should get you close for idle. Use a vaccuum gauge to set mixture so you get the highest possible reading with all screws turned out the same. (could be 2 or 4 mix screws). If it isn't running right at 1.5 turns I would change fuel filters and remove fuel bowls on carb and or carb completly to clean it out. They can be picky if you get a little dirt in them.
 

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Sounds like the float valve is sticking?
 

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I just put a different motor in my car and it has been in for about a month now. While it was cold outside the car ran great. Now all of the sudden the car will not idle. I checked my floats and both were up to high so I have them just below the site plug and was able to run the car with the screw out and gas stayed in. If I turn the idle up it will stay on but as soon as I drop it down to were it needs to be the car dies. What rpm? factory settings are worthless with a "pretty good size cam"

ive always had probs with holleys that have been sitting for extended periods of time. the metering blocks always gummed up and gave me werid probs. you may need to saok them in laquor thinner over nite and blow them out.


I
 

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Discussion Starter #8
Should dribble out of site hole iirc. Gently turn idle mixture screws all the way in. Back out 1.5 turns. That should get you close for idle. Use a vaccuum gauge to set mixture so you get the highest possible reading with all screws turned out the same. (could be 2 or 4 mix screws). If it isn't running right at 1.5 turns I would change fuel filters and remove fuel bowls on carb and or carb completly to clean it out. They can be picky if you get a little dirt in them.
The carb was rebuilt before install. I back them out 1.5 turns and it will still on idle at a higher rpm. Even then when it goes long enough it will still die
 

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Discussion Starter #10
I just found this when I typed holley 1850 tuning

Because the 1850 is designed with a somewhat lean idle circuit, driveability problems occur when it is used on an engine with a big camshaft and low manifold vacuum because the idle circuit cannot supply sufficient fuel to run at light throttle.
 

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I just found this when I typed holley 1850 tuning

Because the 1850 is designed with a somewhat lean idle circuit, driveability problems occur when it is used on an engine with a big camshaft and low manifold vacuum because the idle circuit cannot supply sufficient fuel to run at light throttle.
Not familar with 1850 (I've only messed with 4150/4160), but this sounds like your problem. It only runs at higher rpm because the idle circuit isn't working and the main jets are beginning to kick in as you raise rpm.

???
 

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Discussion Starter #12
Not familar with 1850 (I've only messed with 4150/4160), but this sounds like your problem. It only runs at higher rpm because the idle circuit isn't working and the main jets are beginning to kick in as you raise rpm.

???
When I read that I was kind of thinking the same thing. First is a 500 lift cam considered a big cam and then also why did it run when I first put the motor together. Cause it was cold outside?
 

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I have over .500 lift on mine with a roller cam but I'm using 4150 style. .500 with a flat tappet is pretty high. Try checking your vaccuum if you can keep it running, as you said that was likely the issue. I think mine was 6 to 8 on the carb vacuum port, not sure on manifold.
 

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Discussion Starter #14
I have over .500 lift on mine with a roller cam but I'm using 4150 style. .500 with a flat tappet is pretty high. Try checking your vaccuum if you can keep it running, as you said that was likely the issue. I think mine was 6 to 8 on the carb vacuum port, not sure on manifold.
I can keep it running but it is at a high idle so it would not get an accurate reading. I have an edelbrock carb as well I wonder how hard those are to rebuild
 

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i think my first holley was an 1850. i put center pivot floats on it and a rear metering block. sometimes an engine wants a little more air. there is a screw that adjust the opening of the rear butterflys. the head of that screw is on the underside of the base plate on the passenger side of the carb. take the carb off and turn the screw about 1/4 turn clockwise and it will open the butterflys slightly. try that. i have had to do that on some engines with bigger then stock cams.
 

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The 1850 is the list number and is a model 4160 carb. Base entry level 600 cfm with no electric choke and no ford kickdown lever...normally, unless someone changed it.

First of all make sure your timing is set correctly for that .500 lift cam...that isn't a radical cam by no means as far as lift goes...it's the duration @.050 that comes into play moreso.

If it has lets say 218-224 @.050 for the duration , you should have roughly 12-14 degrees of initial timing in it. That's what mine likes with the vacuum advance on ported vacuum (no vacuum at idle)
But, you haven't given us much info on your engine specs to really pitch in and offer much help.

If the carb was just rebuilt with fresh gaskets and the passages traced and blown out , it should run fine.

Take the carb off and look at the two primary venturi butterflies. With the choke wide open and the curb idle screw set correctly, there should be roughly .020 of the transfer slot showing below the butterflies. Set them so they resemble a perfect square.

Now, while upside down look at the rear venturi and you'll see a setscrew in the base which has a slot in it for adjusting. Back it right off and then slowly turn it in until it contacts the lever above it (keep the slack in the secondary diaphragm tight against it).

After contact..give it 1/4 turn more...as a baseline.

Put the carb back on and warm it up fully. Assuming you have the floats set right, grab yourself a vacuum gauge and set the two idle mixture screws.

Turn them in one at a time until lightly bottomed and then back out until you get the highest / smoothest vacuum reading. You may have to move from side to side and readjust each screw to get it perfect.

I'm no carb expert but i certainly enjoy working on holleys..

There's lots of great info and people on this forum to help out. Just keep us posted...John
 

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When I read that I was kind of thinking the same thing. First is a 500 lift cam considered a big cam and then also why did it run when I first put the motor together. Cause it was cold outside?
Does the choke work?..If so then maybe it is staying on too long or it was covering up a lean condition and now that it is warmer the choke is not coming on?....Usually the cold weather tends to lean out a carb due to more oxygen in the air..If it won't run now in the warmer weather it might be because it is too rich?..How do the plugs look?...Getting back to the camshaft what is the duration @ .050 Lift? That has more meaning than just lift alone..
 

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I can keep it running but it is at a high idle so it would not get an accurate reading. I have an edelbrock carb as well I wonder how hard those are to rebuild
I run Holley's and Edelbrocks and the Edelbrock is probably the easiest carb I've worked on. With the metering rod and jet kit, pretty easy to tune. Big plus is no blown power valve if you get a backfire.
 

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Discussion Starter #19
Does the choke work?..If so then maybe it is staying on too long or it was covering up a lean condition and now that it is warmer the choke is not coming on?....Usually the cold weather tends to lean out a carb due to more oxygen in the air..If it won't run now in the warmer weather it might be because it is too rich?..How do the plugs look?...Getting back to the camshaft what is the duration @ .050 Lift? That has more meaning than just lift alone..
No choke on the carb. Here are the specs

Part Number/Work Order Number 15202
Engine Application 289 FORD
Grind Number 201 HDP

ADVERTISED CAMSHAFT SPECIFICATIONS:
INTAKE: Duration: 284º Lift: .500 Clearance Hot: .000
EXHAUST: Duration: 304º Lift: .520 Clearance Hot: .000

The specifications listed above are based on a rockerarm ratio of .00 IN
.00 EX

RECOMMENDED VALVE SPRING INFORMATION:
Part # 68390-2 Single Dual X Triple
Approximate spring pressure: valve closed: 120 LBS.
valve open: 0 LBS.
8.0
BTDC 8.0
ATDC
ABDC
36.0 52.0
BBDC

The information below is for degreeing cam only. Correct only at .050" tappet lift.
INTAKE Opens: 8.0 BTDC
Closes: 36.0 ABDC
EXHAUST Opens: 52.0 BBDC
Closes: 8.0 ATDC

LOBE SEPERATION 108º

Duration at .050" Intake: 224
Exhaust: 240
LOBE LIFT Intake: .315
Exhaust: .322

If using "Lobe Center" method of degreeing, cam should be installed on an intake centerline of: 104º
 

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Discussion Starter #20
Thanks for all the great advice

finally got it running. I had to turn the screws out a lot and then it started running on its own power. Then I noticed a little gas leaking and the adapter that is on the carb was cross threaded and leaking. I guess I win for worst luck in the world.
 
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