Weber idle solenoid (1 Viewer)

[jfnall]

Weber/Empi 38/38.

I can't seem to get things adjusted to get rid of the engine run-on after the key is turned off. If I get the idle gets down to 400 it will shut off. But to keep things running smooth I need it to idle at about 700-750.

I got an idle solenoid from JT outfitters forth main jet side. Installed and actually ran worse

I took it back out and tested it. Shouldn't a solenoid have some sort of click when power is given to it? Trying to determine if I was sent a bad part. Power to the tab and the bolt part is ground. Am I thinking about his correctly? Ideas?

Thanks

 

[TobyB]

Err, on a 38/38, you'd need 2, as both barrels have idle jets.

And you might not hear a click, but hook up a small piece of tubing to the
nose of the jet- if you can blow through the fuel passageway, it's not closing...

On top of that, the solenoid valve is a fixed jet- as in, you have to change the
whole caboodle to change jetting.

hth

t

 

[jfnall]

Explain to me how this idle solenoid works. If it has power from the ignition, doesn't it open even at idle? Maybe a spring that allows it to close that releases when it get fuel pressure?

And as for needing 2, the secondary side of the 38 is a smaller type fitting. Can't find one that size, so...

The idea is to cut back the amount of fuel while at idle, so if the main has the solenoid cutting if off, then the other side would still do it's thing, but fuel input would be less. Would this be worth taking the time to readjust the carb and try or is this not gonna work at all?

I'm wishing I would have taken the advice by many to stay with OEM setup

 

[lehiguy]

You shouldn't need any cut off solenoid at all if things are set correctly. You may have significant carbon deposits that act as an ignition source when the key is turned off. Try a round (or two) of Sea Foam. I had this issue when I first purchased my 60. The carb was set properly, but once the motor was hot it would deisel when I turned off the key. Sea Foam cured it, never did it again. If the carb is set to best lean idle and there are no carbon deposits, you will be golden.

 

[jfnall]

Only have 5000 or so miles on my rebuild. Don't think i have carbon yet. Would it be possible to get carbon by running rich for all that time? I just have to get down to 500 rpm or less to make the run on go away. Too low to idle well.

 

[lehiguy]

Only have 5000 or so miles on my rebuild. Don't think i have carbon yet. Would it be possible to get carbon by running rich for all that time? I just have to get down to 500 rpm or less to make the run on go away. Too low to idle well.

What's your altitude and what pilot jets are you running? How far out are the idle mixture screws?

 

[klinetime574]

Seafoam it and re-tune your Weber. I bought an Idle Solenoid an never figured the damn thing out so I ditched it.

It looked like you needed to remove the jet from the holder and then put that jet into the solenoid. Maybe I was doing it wrong. But mine ran worse after I had it on. So I took it off.

 

[jfnall]

Idle jets 65 out approx 1.5 turns
Mains 160
Air correction 185

Altitude approx 1500

Running headers
40 over pistons
RV cam
HEI distributor

I have tried all jets up and down 5 at a time idle from 50-75. Mains 142-160 air 185 - 190

It is running best with my current setup
If I go down on idle jets it runs on even longer.

 

[TobyB]

The Weber idle solenoid just turns off the 'idle' (really, progression) jet after you switch off
the ignition. It's supposed to solve exactly your problem.

But having 2 different sizes, I'd bet you have a 32/36- the 38/38 was originally designed for
a small V6, and each barrel fed a bank. So having one shut off and the other not would be
...odd...
But if Empi made it, it might be odd! Do the barrels open simultaneously, or one after the other?

Generic things to check: float level, float valve, fuel pressure (3 or less- really!)...

t

 

[jfnall]

It is a synchronous carb. Both open at the same time.

There is no float window so I'm not sure how to check float level. I did have a problem with the float seat being stuck open at one point. Gas would just flow into the intake long after the truck was still sitting. That's been fixed.

Fuel pressure- I haven't checked it but I am running a stock brand new OEM fuel pump. I could find a pressure regulator that wasn't total crap. Any ideas on one to mount ? Or do I just hook up a gauge a check at idle?

 

[lehiguy]

The Weber idle solenoid just turns off the 'idle' (really, progression) jet after you switch off
the ignition. It's supposed to solve exactly your problem.

But having 2 different sizes, I'd bet you have a 32/36- the 38/38 was originally designed for
a small V6, and each barrel fed a bank. So having one shut off and the other not would be
...odd...
But if Empi made it, it might be odd! Do the barrels open simultaneously, or one after the other?

Generic things to check: float level, float valve, fuel pressure (3 or less- really!)...

t

The jet holders and pilot jet OD are different side to side even on the synchronous Webers. The ID must match.

 

[lehiguy]

Idle jets 65 out approx 1.5 turns
Mains 160
Air correction 185

Altitude approx 1500

Running headers
40 over pistons
RV cam
HEI distributor

I have tried all jets up and down 5 at a time idle from 50-75. Mains 142-160 air 185 - 190

It is running best with my current setup
If I go down on idle jets it runs on even longer.

That sounds too rich on the pilots to me. If you concentrate on the idle mixture screws, where does it improve? Farther open? Farther closed? Try 1/4 to 1/2 turn in either direction, see what it gets you. Going one direction vs. the other should make the idle speed go up. That is the direction you want to explore.

 

[ntsqd]

Even with only air cooled DGV tuning experience 65's sound rich to me too. Naming them "Idle Jets" is misleading, they're part of the fueling circuit until about 3500 RPM. So they're not just an idle setting, they're also a large part of your fueling just going down the road. Need to get them right first, then you can progress to the mains if you need to. I posted the procedure that I used when I was campaigning the DGV on the buggy some time ago. See if you can find it as that sequence made getting the jetting right for any conditions straight forward and easy.

 

[klinetime574]

I am running a parts store fuel pressure regulator set to 2.5 lbs.

I know its a cheap part. But thats the thing. It's cheap. Put one on and see if it solves your problem.

Weber manual states 3 lbs of fuel pressure max. (Of course I never looked up what the stock pump puts out haha)

 

[lehiguy]

I ran mine straight off the mechanical pump for years without issue.

 

[klinetime574]

I ran mine straight off the mechanical pump for years without issue.

Oh really? I really wanna know what the stock fuel pump puts out. Anyone know?

I do know an FPR helped me out with my issues.

Good thread.

 

[ntsqd]

Holley makes a low pressure version of their normal blue regulator. It's range will work with a Weber carb. Used to be that they were red, not so sure any more.

 

[softdrinkviking]

Oh really? I really wanna know what the stock fuel pump puts out. Anyone know?

I do know an FPR helped me out with my issues.

Good thread.

hi, i am reviving this thread because i think i need a FPR.


so basically, i want opinions, do the weber 32/36 carbs usually NEED a FPR, or is using one just a sign of some other, undiagnosed problem?

(if i do have another prob, it's not the floats or jets, and my vacuum at manifold is perfect and steady)

 

[softdrinkviking]

got an FPR

okay, so i got one, and put it on, and it's night and day now.

i was struggling to tune my cruiser, and it has always run rich, so i thought it must be the jets, but they are the right size, and if i went down, it would have been too rough at idle.

so after years of a rich mixture, i got a $25 mr. gasket fpr, and now i can tune it to where it doesn't stink like gas, and it runs like a top.

i say they work. just my 2 cents.

oh, i dialed it at 2.5. i tried 2 and 3, but 2 was too rough, and 3 was little to no change. (could just be that the mr. gasket is a little off, or my fuel pump isn't perfect after 40 years)

 

[klinetime574]

softdrinkviking I have the exact same FPR, and experienced the exact same thing as you when I installed it.

It definitely needs one IMO.

jfnail did you try a Seafoam treatment? I think carbon can build up very fast if the carburetor is not set correctly.