2.0 with dual carbs won't idle when engine is warm

[kmhemi]

I have a 914 with a 2.0 The motor has around 2,000 or so miles on it. It has flat top pistons, Eagle racing cam, dual Weber 40's and mildly ported heads. I installed a Pertronix Ignitor kit as well.

Now, when the engine is cold it starts fine and runs perfect. It idles perfect. Once the engine is warm it still starts and runs fine but it wants to die instead of idle. Do I have my carbs a tad lean or am I not getting enough spark? I have tried the ignition timing at several settings and it doesnt seem to matter.

I set the carbs with a Gunson, While they may not be perfect they're very close. anyone have any suggestions?

[Joe Ricard]

Too rich on the idle circuit.
turn in each mixture screw 1/4 and then "goose it" see where idle sits.
repeat till either you achieve a good idle or you bottom out screws which means you have too big an idle jet. Ideal setting is between 2 and 1 turns out from bottom.

the Symptom you describe is runs great when cold then dies when hot/warm.
Set the timing where it should be and leave it.
set your idle speed after you get the mixture figured out.
synch your carb linkage last.
adjust idle speed as needed once warmed up.

Then post back here to tell me how screwed up I am.

[Kevin Powers]

confusion. you're saying from dead cold start, it idles just fine without feathering the pedal?

k

[Joe Bob]

Got any intake leaks?

[Joe Ricard]

Intake leaks will make it run lean. and funky uneven. Never get the carbs to synch perfect.

[kmhemi]

I checked the bolts on the intakes. They are tight. I sprayed carb cleaner around the flanges to see if the idle changed. It did not. Other than not wanting to idle when it's warm the car runs like a million bucks. When you first start it will idle around 1000 rpms. It will idle for about the first 30 minutes that you drive it. After that you have to hold the throttle pedal to keep it from dying. As soon as you take off moving it runs perfect.

[Joe Ricard]

Did you completely ignore everything I wrote?

TURN THE FIRE DOWN. (Sorry Johnsonville brats commercial)
Back off on the idle mixture screws It is running too rich.

Having tight intake nuts proves nothing.

Also carb cleaner will only make a small barely noticable change if injested by the engine through a small vacuum leak.
Try Ether. Should bog the cylinder.

However, you will probably not notice anything still while dumping a ton of gas down each cylinder.

[kmhemi]

If I change the mixture the engine bogs real bad. It's so sensitive that 1/2 to 3/4 l turn on each carb and the car wouldn't be driveable. Should it be that stubborn?

[kmhemi]

I will try and lean it out some this weekend. I can always mark the screws so I know where I started.

[Joe Ricard]

If you can barely turn the screws in or out then you got a bigger problem.

You haven't stated what size jets you are running for idle.
with that hot motor 55 idle should be in the ball park. Start with one and one half turns out from bottom on the mixture screws.

50 Idles start with 2 turns.

I would also turn in the throttle stop screws to get the engine to run at about 1200 rpm. (do this on both sides evenly)

Now that yo got it running you should be able to turn in the mixture screws to increase the idle speed as it leans out.
now go back and adjust throttle stop screws to attain 900 RPM.

If this is not working then "CAREFULLY" look down the carb throats. look for gas drops hitting the throttle plates. Where is it coming from.... either Acceleration jets in the form of a dribble.
or from secondary venturi or between top cover and body. Floats to high or inlet valve is not seating. Or fule pressure is too high and pushing inlet valve off seat. I HAVE SEEN THIS SEVERAL TIMES.