Issues with Brand New Weber 32/36

[H3nleY]

Hello again!

 

I decided to finally get rid of my China clone Weber 32/36 for a brand new DGV one just for my own peace of mind.

 

After fitting it on, the truck started just fine but immediately bogs down and dies at any touch of the throttle, even when fully warmed up. The idle is also a bit stumbly, varying between 800-1000 rpm. Adjusting the idle mixture screw out does nothing. Closing the choke plates causes the same issues.

 

I am running a low-pressure (2-3.5 psi) electric fuel pump through two brand new filters (one by the tank, one in stock location under hood). Adding a fuel pressure regulator doesn't change anything. The plugs and wires are also brand-new NGK ones and I have checked the firing order. The only things I haven't changed (not stock, just changed around a year ago) are the cap, rotor, points, and coil. The distributor itself is stock.

 

This didn't happen with the clone carburetor. It would also be important to mention that I did recently have an issue with the points closing their own gap and needing to be readjusted.

 

Could there be something not installed correctly in the new Weber? Or is there something wrong with one of the ignition components I haven't replaced?

 

Thanks!

Edited April 25 by H3nleY

[Stoffregen Motorsports]

What jets are in the new carb?

 

If the only thing you changed was the carb, then the problem is either in the installation or in the jetting. I really doubt there's any issue with the carb itself.

 

If you did other work too, then what was it?

[datzenmike]

Loo down the primary and pump the gas. You should see a strong squirt of fuel. Does it?

[H3nleY]

2 hours ago, Stoffregen Motorsports said:

What jets are in the new carb?

 

If the only thing you changed was the carb, then the problem is either in the installation or in the jetting. I really doubt there's any issue with the carb itself.

 

If you did other work too, then what was it?

I'll have to check, I didn't look at the jet sizes 

[H3nleY]

20 minutes ago, datzenmike said:

Loo down the primary and pump the gas. You should see a strong squirt of fuel. Does it?

Yeah the accelerator pump works just fine

[Stoffregen Motorsports]

There are two fuel jets, two air jets, emulsion tubes and pilot jets.

[H3nleY]

3 hours ago, Stoffregen Motorsports said:

There are two fuel jets, two air jets, emulsion tubes and pilot jets.

Okay so good call on looking at the jets, the thought completely slipped my mind when I was checking things over. I compared the new Weber with the China clone and found a few differences.

 

China clone: Both the primary and secondary main jets are 140. The primary air corrector is 170 and the secondary is 160. The primary idle jet is 60 and the secondary idle jet is 50.

 

New Weber: The primary main jet is 140 and the secondary main jet is 135. The primary air corrector is 165 and the secondary is 160. The primary idle jet is 55 and the secondary idle jet is 50.

 

If I'm looking at this right, then wouldn't the new Weber be letting in less air and less fuel? Could that be causing my issues?

Edited April 25 by H3nleY

[Stoffregen Motorsports]

Yes.

[datzenmike]

Look at the jet for blockage. I don't think it's far enough different to not run as you describe. More like, lots of air no fuel.

 

Swap the china 140 main jet in.

[IZRL]

Probably a dumb question but have you checked the fuel pressure at the carburetor? Weber instructions say it needs a constant 3-4 psi.

[H3nleY]

48 minutes ago, IZRL said:

Probably a dumb question but have you checked the fuel pressure at the carburetor? Weber instructions say it needs a constant 3-4 psi.

I haven't run a gauge on it, no. It claims to be 2.5-3 psi. I have it wired to a switch and even with it off, there are no changes in how the truck runs.

[H3nleY]

2 hours ago, datzenmike said:

Look at the jet for blockage. I don't think it's far enough different to not run as you describe. More like, lots of air no fuel.

 

Swap the china 140 main jet in.

I'll swap over some of the jets tomorrow and update y'all then. Thanks!

[H3nleY]

On 4/25/2024 at 4:05 PM, datzenmike said:

Look at the jet for blockage. I don't think it's far enough different to not run as you describe. More like, lots of air no fuel.

 

Swap the china 140 main jet in.

I come bearing news! 

 

I swapped in all of the jets except for the 55 primary idle jet as it's somehow a bigger size than fits in the carb body. 

 

As it turns out though, the problem was just that the points had gotten slightly dirty. Cleaned those off and it started just fine.

 

The NEW problem is it refuses to rev properly. If I hit the throttle, it'll "stumble rev" rather than smoothly rev up the RPM curve. The idle mixture screw doesn't change the issue, although it is out two turns, and the throttle screw just touches the throttle. Even if the throttle screw doesn't touch the throttle at all, the issue remains.

 

Could this be a lingering points issue? Should I get a new set of points? I also have not adjusted the float yet, but I'm not sure if that could cause this.

 

Thanks y'all!

Edited April 27 by H3nleY

[datzenmike]

They should be gaped at 0.018" to 0.022". They shouldn't just get dirty, you should 5k out of them before you have to file them and re-gap. Check your condenser or capacitor. It's job is to reduce arcing when they open. Without a condenser the points life is barely a couple of hundred miles.

 

If messing with the points the timing will need to be checked as an 0.018" gap will be more advanced than a 0.022""

[H3nleY]

21 minutes ago, datzenmike said:

They should be gaped at 0.018" to 0.022". They shouldn't just get dirty, you should 5k out of them before you have to file them and re-gap. Check your condenser or capacitor. It's job is to reduce arcing when they open. Without a condenser the points life is barely a couple of hundred miles.

 

If messing with the points the timing will need to be checked as an 0.018" gap will be more advanced than a 0.022""

I did find it strange too. I ran a piece of a spark plug box through them and it fired right up. I gapped them the "proper" way with the lid of the box they came in so that shouldn't have happened

[Stoffregen Motorsports]

Man, it sure sounds like a carb issue to me. Are all of the mounting nuts tight?

 

The "bigger" idle jet is common on the primary side. Does this carb have an idle cut solenoid? If not, you can install one, and it will help with dieseling. Finding jets for the large jet holder is not hard. I believe Pierce sells them. Any place that stocks parts for DGV Webers will sell those jets.

[banzai510(hainz)]

I just bolt them weber up and they run .  140 135  130 they pretty much run.

[H3nleY]

8 hours ago, Stoffregen Motorsports said:

Man, it sure sounds like a carb issue to me. Are all of the mounting nuts tight?

 

The "bigger" idle jet is common on the primary side. Does this carb have an idle cut solenoid? If not, you can install one, and it will help with dieseling. Finding jets for the large jet holder is not hard. I believe Pierce sells them. Any place that stocks parts for DGV Webers will sell those jets.

Definitely some carb gremlins yeahhhh

 

I didn't adjust the floats out the box so I'll have a gander at those tomorrow. Could too low of a bowl affect acceleration like that?

 

The nuts are indeed tight, as are the two screws for the adapter plate. No idle cut on this one

[bilzbobaggins]

Do you mean that when you stab the throttle it bogs a bit then revs up?  If so, thats very much a 32/36 trait.

[datzenmike]

If the 32/36 had a vacuum secondary it would be perfect. As it is now the secondary tips in at or around 60% throttle so you have to learn where this point is and drive it. I have very little experience with them but the time I drove one on an L16 it felt faster off a start if you 'tipped it in' after the engine gained some speed first rather than just flooring it. It didn't 'fall on it's face' but it lags slightly. The Hitachi with a vacuum secondary only runs on the primary till there is sufficient venturi vacuum and flow to pull in the secondary. The L20B Hitachi is a 30/34 so good throttle characteristics and economy.

 

The 32/36 should run with a wide variety of jets as Hainz says and is tune-able. There shouldn't be a 'fall on your face' bog off idle. In my experience with carburetors this is too much air not enough gas. This is not going to be a vacuum leak as a vacuum leak that bad simply won't idle. Float level is critical on carburetors so check that and the obvious blockage of the primary jet. If it bogs when the secondary engages look at the secondary jet.   

[H3nleY]

She is fixed!

 

The floats were a little too high and the spark plugs, although gapped at .035, needed to be gapped at .030.

 

I have also discovered that the distributor cam lobes are pretty worn, as is the rubbing block on the points since I now realize I never lubed it. Whoops! As a result they don't spread very far when trying to gap them. Will get a new set and probably a new distributor in the near future.

 

Thanks for all the help again y'all!