All Small Six Weber 32/36 rough idle

[bmbm40]

They don’t do pumps crimped together
Is there ANY for the 6’s that are screwed together? ( just filling time till Wednesday )

Well that is too bad... I had pleasant thoughts of having fuel pumps rebuilt whenever it suited me and thwarting Chiner at the same time.
That dream is dead now.

 

[beanmiester]

Update for the masses

Fuel pump checked out at around 4 1/2 psi

The regulator also passed at 2 ish psi


Now I'm going to check the float and needle seat

 

[beanmiester]

In all the diagrams and videos I see that arm is held in with a cotter pin, does that little ring do the same thing and if so is it a one time use?
Also if it is one time where would I get them

 

[Frank]

Yes it does the same thing only better. Can be used repeatedly. Use a thin screwdriver blade or a pried open paper clip, slip in the closed end and pop it off. They are very easy to fly off and never be seen again! Keep a spare finger or small magnet on it when removing.

 

[DON]

And make the spare finger the biggest, fattest one you have!!

 

[beanmiester]

Oh it FLEW . Luckily it landed in a tray the frame makes in the engine bay. Also I found out I have extras in my tool box

 

[beanmiester]

Last update on the carb for all you party people. The carb is all correct. That means something else is causing the issue. YAY!

right now I'm getting different better plug wires (I'm using gross autozone ones atm) and we will see how much of a difference that makes

 

[beanmiester]

Small question for the masses. Routing pcv valve into my air cleaner is a bad idea right? It will gum up the carb. Im asking because this air cleaner has a hole that a plastic pvc elbow sits in and i cant think of what else you'd use it for.

 

[Frank]

PCV systems have two parts to the circuit. 1) The PCV valve is in the valve cover, this line goes directly to the intake manifold, preferable as near the center of the intake as possible. No other vacuum circuits should be Tee'd into the PCV. 2) A second opening into the crankcase that is at atmospheric pressure and is filtered. Usually this is a second hole in the valve cover. Newer vehicles have this side routed to the air cleaner housing with it's own short hose and small air filter.

In operation, the PCV valve draws in blow by in a controlled amount, being driven by direct intake vacuum. Fresh air is draw into the engine from the atmospheric line side as the fumes are being sucked out. But on heavy acceleration and high engine loads when vacuum is at or near 0, the PCV valve is now blocking the blow by from escaping. It must be released, and it escapes by pushing out of the second hose into the air filter and is inhaled by the carb.

Both parts of this system are a must if a PCV system is used.

The atmosphere side does not have to go to the air filter housing, but the PCV valve does have to go directly to the intake manifold.

 

[beanmiester]

Ok got it thanks. Now my second question is if that needs to go directly into the intake where should I draw a second vacuum line from since they cant be connected in any way?

 

[awasson]

A functioning PCV on the small 6 is pretty important. These engines generate a fair bit of crank case pressure. Mine is a year old now since I rebuilt it and it doesn't have as much pressure as it did before break in but I'm sure I'd have pushed oil from the seals if my PCV wasn't in good nick.

Further to @Frank's info, here's a photo of how I routed mine. Mine goes from a new $5 PCV valve from Rock Auto into an oil catch can, in the corner behind the shock tower on the passenger side, sealed circuit with no breathers or anything and then into the fitting on the log just below the carb. The front oil cap is a breather that as @Frank mentioned is necessary.

 

[awasson]

Ok got it thanks. Now my second question is if that needs to go directly into the intake where should I draw a second vacuum line from since they cant be connected in any way?

I was wondering that as well, especially since I'll be putting in power brakes at some point.

 

[beanmiester]

Right now everything is tied in because i didn't know it was supposed to be. Im mostly curious because I cant see another vacuum source on the engine and my transmission/brakes needs one. When i got the car it was all tied in on one line.

 

[awasson]

Right now everything is tied in because i didn't know it was supposed to be. Im mostly curious because I cant see another vacuum source on the engine and my transmission/brakes needs one. When i got the car it was all tied in on one line.

Right. The transmission needs one as well. My first job out of high school was as a transmission service tech. I've been driving manual for so long, I forgot autos have a modulator that needs vacuum.

 

[wsa111]

Get rid of the mechanical fuel pump & get an electric pump & run a return line to the tank to cool the fuel off. Keep the fuel pressure regulator at 3 psi.
Mount the carburetor on a phenolic space to prevent some heat from the Weber. Good luck. Vapor lock is causing your problem.

 

[awasson]

@beanmiester, I know you did some troubleshooting offline. Did you manage to resolve the problems you were having?

 

[beanmiester]

Nah. We think its vapor lock but since the carb doesn't need much pressure it keeps chugging along. Im getting an electric pump and an afr meter

 

[beanmiester]

So for for now I'm trying to figure out the vacuum situation that way my booster isnt gets crank case fumes

 

[awasson]

I don't know if we covered it in the earlier discussion but I was reviewing and noticed that you mentioned an electric fan controller. I had an electric fan on my mustang for a very short time and I experienced nothing but trouble because the carb, at least in my situation needed the air circulation to prevent vapour lock. I put the 5 or 6 blade fan back on and everything was fine again but even though the electric fan cooled the rad better than the mechanical one, as soon as the engine got to temperature, bad things happened.

I intend to go with the electric fan again at some point and I've made some changes to allow for that. I have a phenolic spacer to install and I've routed all of my hoses away from the engine. Gas line was just touching the valve cover before. I'm also going to make a heat shield for between the valve cover, which gets smoking hot and the float bowl and I'd like to make one for the exhaust side as well. I should have ceracoated the header.

 

[beanmiester]

My carb gets to about 110 at the max which makes sense because its in the hundreds where I am. A mechanical fan pushing hot air didn't cool it off any compared to the electric. Basically my carb is always just slightly hotter than ambient temperature