All Small Six Weber 32/36 rough idle

This relates to all small sixes
You probably have the idle screw turned too far in causing the throttle plate to open past the ported hole.
 
You probably have the idle screw turned too far in causing the throttle plate to open past the ported hole.
The carb settings were all wrong. I got them alright now.

So i have the idle set to 750 which is 1 3/4 turns out for the idle speed screw and the dui on manifold vacuum. When in gear (reverse and drive) it drops to 550. Using the ac in park it drops to 650-600. When in gear and ac on it goes to 450. Does that seem right?
 
I see no problem except maybe with the last number, a little slow, but if you don’t have problems stalling, run it. If you do, you will have to raise everything 1-2 hundred. You could get fancy, newer stuff has a little solenoid the kick in a little extra throttle, triggered by the ac. A pain for 3-4 hundred rpm
 
Do you guys know of a fan controller that can use the existing temperature sensor or something not too crazy to tell the fan when to kick on?

This one i have is alright but it kicks on inconsistently and for too long. Its just this probe that sits on the radiator and activates a relay.
 
It's some aftermarket distributor a shop put on for me because they broke my original. It has the spark advance valve thing built into it and maybe a centrifugal advance (that might explain why it seemed to advance without vacuum imput). I ordered a dui a few weeks ago. The carb just happened to come first
You're going to love the DUI. It was a game changer for me. I live in the mountains and that DUI made hill climbs a lot easier.
 
I can already tell the engine is performing better. 1500 idle feels as smooth as how the old 500 idle felt. That new carburetor also helped a ton. Its way more responsive and it holds rpm way better than my autolite did. I just need to swap out my speedometer cable and I'll be driving it again. I took it off to connect the rally pac so I might as well change it while I'm here
 
The carb settings were all wrong. I got them alright now.

So i have the idle set to 750 which is 1 3/4 turns out for the idle speed screw and the dui on manifold vacuum. When in gear (reverse and drive) it drops to 550. Using the ac in park it drops to 650-600. When in gear and ac on it goes to 450. Does that seem right?
Just FYI- idle speed changes when a load is added are less with ported vacuum.
 
About how much of a difference does that make? At idle it seems to like manifold a little more and doesn't miss as much compared to ported. I have issues with 4 and 6 running rich but if I lean it out more the rest are too lean. Manifold seems to have fixed that a bit because of the advance at idle
 
About how much of a difference does that make? At idle it seems to like manifold a little more and doesn't miss as much compared to ported. I have issues with 4 and 6 running rich but if I lean it out more the rest are too lean. Manifold seems to have fixed that a bit because of the advance at idle
The benefits of manifold in your case justify leaving it. The engine still drops rpm when a load is applied with ported. It's less drop because the idle throttle is open more without the extra advance, plus-depending on the distributor diaphragm- the timing may retard as the vacuum drops with the added load.
 
Good point. These old cars have decades to generate electrical gremlins. When I had the engine out last year, I installed a new ground strap from the back of the block to a threaded nut-sert that I put into the firewall and my battery ground strap goes to the engine block as well. I replaced all of the electrical leads from battery to starter and grounds and checked my alternator wiring and grounding. My starter solenoid is fine but ancient so I recently changed that as well. I also added relays for the headlamps and high beams which I use the headlamp switch to trigger. Better safe than sorry.
I know this is kinda old but where did you ground from the engine? My voltage is a bit low with headlights on and a fan and I'm not seeing a ground on the back of my engine
 
I know this is kinda old but where did you ground from the engine? My voltage is a bit low with headlights on and a fan and I'm not seeing a ground on the back of my engine
I took my ground cable from the battery and bolted it to the block. I think there was a bolt just behind the lower alternator bracket. Then I took a braided ground strap from the top passenger side bell housing bolts and took it to the firewall. I drilled a hole, sanded the paint around it and installed a riv-nut with a washer and connected the ground strap with a nice shiny new bolt so I’d get a good electrical connection.
 
So I'm stumped. The car was running great for two days. Stopping well, idling perfectly, being able to use the ac while idling and then today I start it and its having trouble idling. I try to start it and its having issues at high idle. They stop eventually so I kick it down to idle and its having trouble keeping rpm. Its fine(950) then crashes to 400 out of nowhere. I got to the back of the car and I can hear fuel gurgling in the exaust. I let it run for a bit and it stops gurgling. I turn it off and blow air through the carb to dry up the cylinders and I pulled a plug to make sure it wasn't wet in there anymore. I start it up again and its doing alright until it suddenly isnt and starts crashing again. I thought maybe I need to adjust the air mixture but giving more or less fuel causes the engine to stumble harder and not recover. I messed with it more until it would pull 18 vacuum then crash to 10 and then go back to 18. I checked the voltage with a multimeter and the battery was reading 14 with the car running and so was the power from the ignition. I have no clue why the car runs so rich. This problem has persisted on every carb i have used. Does anyone have any ideas?
 
You need to check/ verify fuel pressure at the carb. Webbers have to have very little, like 3 psi if I remember right. I am starting to come to the realization that a fuel pressure guage at the carb should be mandatory
 
I recently checked the fuel pressure on my van's 200 w/stock mechanical pump and it was 5 psi up at the carb connection. This was an acceptable reading for the Mercarb/2G, but may be a bit much for your Weber.
 
Weber’s need a low pressure fuel regulator. I run a Holley 1-4 psi regulator #12-804 on my triple carb set up. No problems since installing the regulator. Members have reported the Mr. Gasket regulator failing and leaking fuel.
 
You need to check/ verify fuel pressure at the carb. Webbers have to have very little, like 3 psi if I remember right. I am starting to come to the realization that a fuel pressure guage at the carb should be mandatory
Ill put one but I have a webber fuel regulator before the carburetor
 
1. How old are they?
2. Where is your fuel filter and what kind?
3. Do you use ethonal free gas?

If more than 3 or 4 years old on the needle/seat, especially if you don’t use ethanol free, it would be worth a check. Ethonal is hard on just about everything, especially if the car sits for any length of time.
If you can inspect the fuel filter that helps. Look for trash. I had a filter elliment disinigrate and cause problems. It had been in 5-7 yrs with very little mileage
 
1. How old are they?
2. Where is your fuel filter and what kind?
3. Do you use ethonal free gas?

If more than 3 or 4 years old on the needle/seat, especially if you don’t use ethanol free, it would be worth a check. Ethonal is hard on just about everything, especially if the car sits for any length of time.
If you can inspect the fuel filter that helps. Look for trash. I had a filter elliment disinigrate and cause problems. It had been in 5-7 yrs with very little mileage
Everything is only four months old and the longest down time I had was a week. The fuel filter is before the fuel regulator and its a metal one from Napa. Sadly I don't have ethanol free gas here.

Im having such a hard time diagnosing and figuring this car out because damn near everything but the engine itself have been replaced and it will run great then horrible out of nowhere
 
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