Ive got a Weber 32/36 DFEV and i cant get it to idle properly. Its been surging high and low on idle. When i look down the throats at idle, i can see the aux venturi is spraying fuel out. Ive adjusted my float levels higher and lower but it doesnt seem to be affecting this. Ive now reset it to the original

What else would be causing this to happen? Suggestions on how to fix this

yeah that can be to high float or leaking float valve/seat.
fuel is no suppose to come out of there at idle. Also idle air set to high will do that, to high fuel pressure.

about all I can think of? I got more experience with EFI though.

What fuel pressure are you running ???

Don't know about 32/36 DFEV specifically, but in generall Weber's don't like more than about 3.5 PSI.

Yep, check fuel pressure.

I don't remember having an alternate username I'm having the exact same problem, but have been chiseling away at it.

My rough progression was like this:

Fuel regulator malfunctioned.
I took the top off the carb.
needle and seat malfunctioned.
discovered jetting was wrong.
Checked all the jets but the inside of teh carb is squeaky clean.
replaced needle and seat.
checked runner manifold flanges for trueness.
flattened manifold flanges.


Now I'm up to replacing a couple of the jets. Removed most of the over rich condition, but the hunting idle remains which is a bummer. I haven't looked down the top of the carb while it's running yet.

The hunting idle didn't happen before the regulator issue. the power valve diaphragm seems to be fine. If the jetting doesn't fix it I'm officially stumped. There is nothing left.
I have mine running a lot better as a result, but the idle is still wrong. If you make progress OP, say what you did!

im using a stock mechanical type fuel pump. without a gauge, i guess the only thing i can do is check the max pushrod height. any other suggestions?

Yeah, even tho mechanical pump I'm still thinking fuel pressure... AFAIK fuel squirting out of there can really only be fuel pressure.

From memory a stock pump does around 3-3.5 PSI when the pushrod height is correct... so presumably they can go over the 3.5 PSI if the max height is higher.

3.5PSI is still a little too high for a Weber. Mine is set to a shade over 2.5PSI.

When it is ran over the max pressure which is 3PSI I think, they can misbehave pretty badly and intermittently.making faultfinding hard.

Your problem haunted my dreams last night so feel privileged.
You shouldn't be seeing any spray from the secondary jet. The secondary throat should be closed at idle, therefore no vacuum to suck fuel out.
Either your secondary throttle plate is incorrectly adjusted or your float bowl is overflowing.

i think u might have misunderstood. Its dribbling from the auxiliary venturi of the primary throat. Nothing is coming out of the aux venturi of the secondary.

just checked my fuel pump pushrod. it seems all ok but have put a few more gaskets underneath. fuel seems to be coming out at a reduced rate. anyway borrowing a gauge tomorrow to see whats what

I see. I did misunderstand. Sorry about that.

I found / have some nice cutaway diagrams of the weber. Will try to dig them up later today if i didn't save them I need to visualise this a little better.

Are you saying that your main is putting fuel down the primary throat at idle instead of just the idle on the main?

bingo

just to clarify, on the primary and secondary venturis, there its a smaller venturi at the top of the carb (when u look down into it). This is called the auxilary venturi. The main jet feeds fuel through the piping into the aux venturi and hence you have your main circuit running.

so checked the fuel pressure. its about 2- 2.5psi so all good

called a carbie specialist and explained the problem. they immediately said that ive most likely got a blocked idle jet. so blew took out all the jets and the idle mixture screw and blew thru all the passages with compressed air.

and guess what... its all good! now just got to dial in the jetting properly