Weber carb - return spring woes

My throttle usually doesn't return to idle when I let off the gas pedal. So far everything I've tried has made it worse. The Weber 32/36 DFAV carb has a rotary return spring on the main throttle shaft; I've tried repositioning it and winding it extra tight and it does not like that at all. (causes more binding with no benefit of returning it to idle)

There is also an external return spring, I assume it was there for the stock carb before the weber was put on, and it basically doesn't help. It seems like it's positioned wrong.

So tonight I've got an idea to fab up a couple steel brackets and install the external spring in a position to work better. I'll post pictures of it below if this works.

If anyone has solved this problem or would strongly suggest I don't do what I'm doing??? I'll check this again before I start drilling.

Cheers
c.j.

The stock return spring on the carb is not strong enough to return the throttle plates to idle, as you know. You need to have an external return spring to get the carb back to idle, and have it aligned for max pull with the least amount of tension so you don't need 2 feet to push it down. I use a universal double carb return spring on Geronimo's 32/36 DGEV and I have no issues.

Also try using WD40 or some other light spray lubricant on everything - cable inner, linkages etc. Minimise the drag needed to release the throttle back to the idle stop. I had to modify the return spring set up and throttle linkage on my 34DATA carb by taking the spring bracket and throttle linkage off the Mikuni, drilling a relocated mounting hole in the spring bracket and mounting it to the electric choke retainer. I was able to use the Mikuni throttle return spring and mount the linkage the same way the Mikuni had been set up.

I've always tapped the throttle and it goes back to idle

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Originally Posted by Salteen

I've always tapped the throttle and it goes back to idle

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But mine doesn't do that, it just keeps racing.

I think this worked. There wasn't a good place to hook a spring (at either end) so I added a bracket onto the throttle lever and another on a manifold bolt to anchor it.
Before:
Attachment 24444
After:
Attachment 24447

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Originally Posted by geezer101

Also try using WD40 or some other light spray lubricant on everything - cable inner, linkages etc. Minimise the drag needed to release the throttle back to the idle stop. I had to modify the return spring set up and throttle linkage on my 34DATA carb by taking the spring bracket and throttle linkage off the Mikuni, drilling a relocated mounting hole in the spring bracket and mounting it to the electric choke retainer. I was able to use the Mikuni throttle return spring and mount the linkage the same way the Mikuni had been set up.

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Yup, custom fabrication!

yeah then either A your idle needs to be adjusted or B your return spring is bad. I used the factory late on mine and repositioned my throttle cable to the opposite side of the engine bay.

My goofy 34 DATA has the throttle shaft configured differently - the electric (well, was a water choke...) is directly over the primary throttle shaft where the throttle linkage is mounted. This thing caused me grief as the throttle cable barely passed the choke housing and the choke adjuster screw hit the intake manifold. Took me ages to set up the spring mount as the spring was hitting the auto choke housing as well :rolleyes: I had to tap a thread in an alternative location for the throttle stop (there was a provision for it luckily) Your throttle return spring set up is much better than some I've seen. The good thing is it's linear with the linkage and the cable.

34 DATA? If that's a variant of the DMTR/DAT/DATR/DATRA design, those are designed for transverse engines (like my Lancia and various '70s Fiats) that orient the barrels fore/aft. That's why the float bowl is horseshoe-shaped, so one lobe or the other always has fuel feeding the jets during hard cornering in either direction. On a longitudinal engine orienting the barrels left/right, cornering in one direction can starve the jets and in the other direction flood them, tho' granted we may never corner hard enough in these trucks to run into that anyway.

Yeah, it is. It was originally off a Lancia Beta 2.0 twin cam. I would have to be pulling some decent lateral G's to starve the fuel bowl of fuel. You being a Lancia owner will sleep better at night not knowing what I've done to this carb. It was a real mess when I salvaged it and it's taken some fiddling to get it to operate in the same configuration as the Mikuni did from factory. I did notice the fuel bowl had a gallery drilled through it from one side to the other (although this one was hell clogged with sediment and contaminated fuel)

For some reason I felt compelled to pull the whole engine out of it even though I'd never do anything practical with it. It was actually a beautiful looking engine even though it was completely caked in crap :( (FYI I didn't grab it but if I had, that sucker was going into a Fiat X1/9 the minute I found one...)

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Originally Posted by geezer101

Yeah, it is. You being a Lancia owner will sleep better at night not knowing what I've done to this carb. It was a real mess when I salvaged it and it's taken some fiddling ....

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Man - it's going to totally suck when they make us all go to electric cars and we don't have carburetors to occupy our spare time.

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Originally Posted by charger_john

Man - it's going to totally suck when they make us all go to electric cars and we don't have carburetors to occupy our spare time.

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Electric cars are bad news - way worse than a 40 year old Italian carb... nobody's talking about it yet but the sh*t is making it's way to the fan. Maybe one day someone will dig up this post and go "was this dude an alien or a clairvoyant or something...?"

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Originally Posted by geezer101

It was actually a beautiful looking engine even though it was completely caked in crap :( (FYI I didn't grab it but if I had, that sucker was going into a Fiat X1/9 the minute I found one...)

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It's basically the same Lampredi-designed twincam engine as used in the Fiat 124 and others, just leaned over by ~20° and turned sideways to drive the front wheels, with a few other minor alterations to account for that. The transaxle was designed by olde-skoole Lancia engineers specfically for the Beta and evolved to see continued use in later FWD Fiat, Lancia and Alfa Romeo models. The Beta powertrain also went into the mid-engined Lancia Montecarlo, which otherwise used mostly X1/9 running gear but in a slightly larger body designed and built at Pininfarina.