Car wont run triple webers

[jonbill]

There's mixture screws per cylinder, throttle stops per carb, linkage per carb, possibly idle air bypass per cylinder and idle jets - all affect idle and off idle response. You Deffo need to get same air flow values for all cylinders at idle.

[jonbill]

I have a couple of these between my linkage and the valve cover to ensure it all closes.

https://www.dellorto.co.uk/shop/weber-carburettors-parts/carburettor-parts-weber-carburettors-parts/dcoe-dcosp-parts/linkage-return-spring-lt5000/

I'm sure you'll be able to get something similar closer to home.

[240260280]

Initial Tuning of Weber DCOE or other Side Draft Carbs

What are the model and series numbers on each of the 3 carbs?  e.g. 40DCOE151

Important: Make sure fuel level is same on all carbs.  Ignore any web sites that say 25mm  down from jet bridge as fuel will spill into carb throat. ~ 29mm down is where to aim according to many sources.

 

Idle Balance:

1. Set all the idle enrichment screws to the same number of turns out.

• If you have 151's (made in Spain) then turn all the 6 idle enrichment screws all the way in then each turn out 1.75 turns (1-3/4). Also close the air bypass screws.
• If you have others (made in Italy) then turn all the 6 idle enrichment screws all the way in then turn out 0.75(3/4) turns

2. Warm up the car, disconnect the 3 push rods, and then adjust the idle air flow for each of the 3 carbs.

• measure the flow to all 6 carbs
• adjust the idle stop on each carb so that all 6 are equal in air flow.
• if the flow between two throats is different on the same carb AND you have 151's then us the air-bypass on the lower flowing throat to increase its air flow to match its partner.
• if the flow between two throats is different on the same carb AND you have non-151's then you may have a bent throttle shaft and drilling a small hole in the lower flowing throttle plate can bring back the balance. (Don't do this until you take carb apart and inspect for other possible problems like throttle plate wear, etc.)

 

Off-Idle Balance:

1. Install throttle arms and make sure they do not push on carbs so as to increase idle rpm or air flow.  These arms should have no influence at idle. You can do this by not tightening the three throttle arms at the main throttle linkage bar on the manifold until all push rods are attached to the carb lever arms.

2. Have a way to solidly turn and hold the linkage to off idle ~ 2000 rpm and measure air flow.

3. Note the carb flowing the least and use the turnbuckle adjuster on its push rod to extend the push rod so that the air flow increases.

4. Loosen all push rods at main throttle linkage bar and repeat #1 to #4 until the off-idle is as balanced as you can make it.

 

The next tuning steps are to get jets and air correctors right. You need an a/f  wideband O2 setup to do this precisely otherwise note engine note, plugs, and driving and adjust to taste.

We can give suggestions for jetting if you share engine displacement and mods.

Edited September 15, 2019 by 240260280

[hatepotholez]

Thanks guys.

 

they are 40dcoe151’s, Italian made. From what I know it’s a stock cam and engine is stock, I did just install headers 6-1 and a full exhaust from motorsport auto. I believe pipe diameter size is 2.5.

Edited September 15, 2019 by hatepotholez

[Patcon]

IMPORTANT! Do not over tighten any jet screws. Lightly seat them and then back them out as desired. You can damage the precision holes at the bottom if you over tighten them!

[240260280]

Is it a 2.4, 2.6 or 2.8 litre engine?

[hatepotholez]

sorry, 2.4

[240260280]

What are the idle jets, main jet, main air corrector, and choke size?

This works for a higher compression L24:

 

40DCOE151 (3)

30mm Choke

Fuel Height: ~30mm down from top of body

Idle Jet: 55F9

Enrichment Screws: 2.25 turns

Emulsion Tube: F11

Air: 170

Main: 120 

 

[240260280]

These work too:

 

 

Edited September 17, 2019 by 240260280

[hatepotholez]

I'm guessing this would work as a return spring, but I would need 3.

 

https://www.piercemanifolds.com/product_p/lt5000.htm

[jonbill]

That's the sort of spring. But you don't have to use it like that.

Here's how mine is setup with 2 of those springs. You can see them on the linkage by the filter on the cam cover.

 

 

 

[hatepotholez]

Ok some updates. I installed a home depot spring to the throttle linkage. Then I sent the car off to a specialist.  He got the car running(as did I) but it takes a tremendous amount of gas to get it started and then with the slight touch of the gas pedal the carbs spits like crazy. He put full chokes on and the car wouldn't start, then he started covering some of the carbs air horns while starting it and finally got it running. He stated the carbs are not giving enough fuel to get the car started. He will check if the chokes or jetting needs help.

Would the idle air mixture screws prevent it from cold starting even if the chokes are on?