What are these screws on a Weber 32/36 (also rough idle cold) SOLVED!

[Guest zaeos]

I am having a rough idle when cold problem and i am trying to figure out what the heck these screws are (not shown is the one near the ported vacuum):

 

Here is a little background on what I've noticed and tried so far, any suggestions would be helpful:

When i start the car cold with the choke engaged it will fire up and run great for about 20 seconds, after that it begins to misfire and progressively gets worse, accompanied by a knock/tapping, until it starts to warm up a little. When at full operating temp is runs fairly well, not perfect but well. 

Another weird note.... unplugging the idle cut-off has no effect.

 

History:

I purchased the car after it had sat in a garage for about 10 years. It ran rough when i managed to get it fired up before doing anything... go figure. Here is what I've done to rectify the lumpy idle since:

-valve adjustment .07 using go/no-go

-rebuilt and re-jetted the carb according to the advice on this forum

-I've done plugs, wires, distributor cap and rotor

-replaced the distributor with a rebuilt cardone, added a hot spark ignition

-removed the resistor wire for the blue coil installed by PO

-removed the smog equipment and wiring, plugging the intake and exhaust manifolds

-sprayed carb cleaner in every possible hole and mating surface i could find with no change to idle

-set timing

-Cleaned contacts and replaced ground wires for battery and alternator ( although i did notice recently that my fuel gauge will occasionally jump while warming up... never does it hot ... hmmmmm a clue maybe? )

-washed the windows and greased the muffler bearings

 

Come on wonderful forum!!! Who's got the magic answer?!!?!?!

 

 

 

 

Edited April 5, 2018 by zaeos

[TobyB]

Red circled is a plug.  No idea why they do it like that. Maybe to make it easier to clean out?

The old way was a hard- to- remove and even harder- to- replace lead plug...

 

There are no magic answers- you just go 'round and 'round, and if

you're lucky, things get a little better every go- round,

OR

you learn something useful from when things get worse, instead.

 

You've already hit many of the usual suspects, so I suspect you could

figure it out if you beat your head against it long enough.  That's the only way I seem to learn...

 

Unplugging the idle solenoid should kill the engine, mostly.

So either it's not working, open or shut, or you're running with

your idle screw so far open you're running on the main.

If your pic shows a fair approximation of the idle stop, then the solenoid's stuck open.

 

Running worse after 20 seconds makes me think maybe the carb's flooding

(float level or fuel pressure) or it's so stinking rich that the plugs are fouling.

You can check that by starting it, letting it die, and then examine the plugs,

and also look to see what's going on in the carb- if you see fuel running down,

it's flooding.

 

Put the timing light on it while it's running, warmed up, and see if the timing jumps around.

The front pulley's better for this, altho enough marks on the flywheel will work, too.

 

for starters,

t

 

Edited February 7, 2018 by TobyB

[Healey3000]

What kind of fuel pump are you running - stock or electric?

[Guest zaeos]

Thanks for the quick reply! weird idea for a plug!

I suppose your right.. just need to keep at it.

 

Looks like ill have to do some solenoid testing....

 

I set the float level to 40mm ... speaking of fuel pressure could the stock fuel pump cause this type of issue if it needs a rebuild? Any way to test?

 

The idle screw is about 2 turns out... The 60 main idle jet i started with had no effect backed out past 3 turns so i went with a 65, should i up the secondary idle from 55 to 60 as well? (pic is off the internet... too lazy to go downstairs rn!)

 

Timing light used to jump around, and it did so less with the hot spark and is pretty solid with the cardone distributor. My light is pretty cheap however and I'm seeing what could be a misfire ( unsteady light ) ...or just sh*tty equipment

 

 I'll go through some more things this week and report back.....

 

Thanks agian!

 

 

 

[ray_]

And what plugs are you running?

 

(There are about 2 correct answers)

 

p.s. My carbed car is doing the same thing. I'm about to plug in a fuel pressure gauge.

 

Cheers,

[kbmb02]

Q: What kind of choke: water or electric?

[Guest zaeos]

Thanks for the responses!

 

ray_: I am running NGK BP6ES plugs

 

kbmb02: It's a water choke, when i kick the pedal the butterflies close and the fast idle engages, but as soon as i touch the pedal the fast idle kicks off and it chugs or stalls... are you thinking it might be choke adjustment?

 

[Mark92131]

Q: What is your compression in each cylinder?

 

Mark92131

[borgpj]

Sure sounds like too much choking.  The best way to verify one way or the other is to remove the air cleaner and observe the choke butterfly soon after you start the car.  If the car runs better when you manually open the choke butterfly a bit, it probably needs to be adjusted to open faster.

[Guest zaeos]

1 hour ago, Mark92131 said:

Q: What is your compression in each cylinder?

 

Mark92131

Compression when i first checked, again with a sub par gauge that my friend said gave low readings, was between 95-110 psi ... seems pretty close to each other but maybe not close enough?

 

9 minutes ago, borgpj said:

Sure sounds like too much choking.  The best way to verify one way or the other is to remove the air cleaner and observe the choke butterfly soon after you start the car.  If the car runs better when you manually open the choke butterfly a bit, it probably needs to be adjusted to open faster.

Thanks! I'll take a look when i get home today.

[Guest zaeos]

Quote

 

Ok... update on testing the choke: 

I started the car choke closed and fast idle on... when i opened the butterfly manualy the rpm's picked up significantly but i wouldn't say it ran smoother. I then kicked it down into regular idle and openend and closed the choke which had little effect on the idle.

 

I did not see any fuel  running down into the carb while it was idling.

 

My hunch is something between an electrical gremlin/bad ground.... the car still bucks as i increase the throttle and tuning on the carb seems close to correct from all my research. I'm going to do some gremlin hunting this weekend and see if I can't locate it and ground my dash gauges while I'm at it.

[Scottwattz]

I've been working through the same issues. Ive cranked in the fast idle screw and left the electric choke about a 1/8" off the wall. What did help was resetting the air fuel screw. Still not a great cold cranker but its better. And she screams all the way to the second barrel. Would like to know more on this issue as mine likes to rev UP as it gets warmer.

[Dudeland]

12 hours ago, Scottwattz said:

I've been working through the same issues. Ive cranked in the fast idle screw and left the electric choke about a 1/8" off the wall. What did help was resetting the air fuel screw. Still not a great cold cranker but its better. And she screams all the way to the second barrel. Would like to know more on this issue as mine likes to rev UP as it gets warmer.

When I kick off the high idle mine will drop to about 600-700 RPM until it is completely warmed up then it sits nicely about 900. 

[Scottwattz]

That's my problem is there is no high idle to kick off as of yet

 

[jimk]

3 hours ago, Scottwattz said:

there is no high idle to kick off

Open the throttle a bit, lift the fast idle cam operating rod so the fast idle screw is on the cam step. Use screwdriver to set the fast idle with the fast idle screw on the cam.  This can be done without the engine running.  If so, then start the engine and if the fast idle cam has dropped, re-set it by hand same as before and readjust fast idle speed.   Then open the throttle to make sure the fast idle cam drops off the fast idle screw again and the normal idle is being controlled by the normal idle speed screw.  If these terms are not understood, either read the manual or take it to a qualified tuner.