chris r

chrisr hz tonner discussion

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I was gunna ring weber spec tomorrow re carbs for my eh but maybe not now haha

Dont start me on single barrel strombergs arhhh

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Just now, sr2 said:

LOL, I'd be taking Weber Specs comments with a grain of salt. They have a reputation for being somewhat.... ahem..... "opinionated" to say the least, (looks like they were angling to sell you a new 32/36?).

I ran an XE Coon in the early 90's and the 34ADM on it started, idled and ran smoothly - a huge improvement on the stromberg carb on the XA Coon I'd had before.

 

It's hard to escape that this has been a very common swap in Aussie for decades and most use the existing 'Coon jetting. 

Classic example from the GMH-Torana Forum - these guys know their stuff. 

http://www.gmh-torana.com.au/forums/topic/75566-weber-34-adm/

All I took away form him was only interested in selling me a new carb and some other expensive adapter and water line kit for the manifold 

They also sell a rebuild kit for the 34 adm if they were as shit as they say why do they stock parks for them....

 

I've found nothing but good reviews about the 34adm in my research 

It can't be worse than the single barrel stromberg that I took off 

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32 minutes ago, rusty360 said:

I was gunna ring weber spec tomorrow re carbs for my eh but maybe not now haha

Dont start me on single barrel strombergs arhhh

He tried to sell me everything "just drop your manifold off and we'll do the rest"

I stopped listening when he was rattling off prices and it went past the $1000 mark plus gst. 

 

Based on the 'they are shit but buy our new stuff' response I'd avoid them as much as possible tbh 

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The following jetting, apparently gives excellent throttle response, very smooth idling and excellent pickup on secondaries.
For a stock 3.3l Crossflow Motor.

Primary Idle: 75 (70 factory fitment)
Secondary Idle: 65 (60 factory fitment)
Primary Fuel: 140 (135 factory fitment?)
Secondary Fuel: 220
Primary Air: 160 (160 factory fitment)
Secondary Air: 180 (160 factory fitment)

 

Taken from 

http://www.ozfalcon.com.au/index.php?/topic/8610-weber-carb-34adm-master-thread/

And

http://www.ozfalcon.com.au/index.php?/topic/7026-ford-registered-technician-bulletin-34-adm-weber-carb/

 

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21 hours ago, Bearded Baldy said:

The following jetting, apparently gives excellent throttle response, very smooth idling and excellent pickup on secondaries.
For a stock 3.3l Crossflow Motor.

Primary Idle: 75 (70 factory fitment)
Secondary Idle: 65 (60 factory fitment)
Primary Fuel: 140 (135 factory fitment?)
Secondary Fuel: 220
Primary Air: 160 (160 factory fitment)
Secondary Air: 180 (160 factory fitment)

 

Taken from 

http://www.ozfalcon.com.au/index.php?/topic/8610-weber-carb-34adm-master-thread/

And

http://www.ozfalcon.com.au/index.php?/topic/7026-ford-registered-technician-bulletin-34-adm-weber-carb/

 

I'll pull the top off on the weekend anc check/compare with what I've got and go from there

 

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Ordered a sigma wideband off 14.7 so I can see what's going on in real time. 

Will chuck the points dizzy back on as a test and see if it behaves less badly with that 

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Hey I have been thinking about your carb issue and a comment you made got me thinking.

Can you post a pic of the fuel shut off solenoid fitted to your carb?

I think there are two types of solenoid for the pre and post emission control carb.  I think (but don't know) that the early pre emission control carb like yours is supposed to have a solenoid that has the low speed jet incorporated into the assembly as shown in the picture below. The later version like my carb has a separate low speed jet and the solenoid is a plunder type item as shown in the other pic.

I think there is a chance that you have the wrong solenoid and if this is the case your carb will be running with no low speed jet and nil fuel metering on the primary barrel. If this is true I expect it would be running ridiculously rich.

Have a look here

https://www.progas.com.au/portfolio_category/carburettors-accessories/ 

Idle solenoid 1.jpg

idle solenoid.jpg

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I've got the solenoid like the first picture.

Thatd make sense if I had the wrong one 

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Alright I am sure we have nailed the issue, it seems highly likely that you are missing the jet for the primary low speed fuel circuit. This would certainly explain the problems you are having.

This is probably not your fault as I expect the carb came with the incorrect solenoid assembly installed. 

All you need to do to fix it is throw the junk solenoid in the bin and replace it with one of these.

https://www.weberperformance.com.au/product_info.php?cPath=6_268&products_id=1345

I would also purchase a selection of these

https://www.weberperformance.com.au/product_info.php?cPath=6_268&products_id=631

I would grab a 55, 60 and 65 as you may need to experiment to see what suits best.

When I tuned mine I used a wide band O2 sensor and a stand alone gauge. From memory the AF ratio on the gauge looked best with a 60 installed but the car seemed to run nicer and pull better under load with a 65 installed. I decided the seat of the pants dyno was telling the truth and went with the 65. 

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Hey any chance you can post a picture of exactly what is installed in this position on the carb. This is where the low speed fuel circuit jet is supposed to be installed. This jet is responsible for fuel metering from idle and remains active up until around 3000 RPM when the main jets progressively take over the fuel metering. I believe you should have either the integrated  jet/solenoid assembly as shown in the above post (bottom pic) or the alternative solenoid delete option as fitted on my car.

Chris r Weber pic.jpg

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Yw9N4HD.jpg

That's the solenoid I've got in the carb. 

Looking down the hole there doesn't seem to be any provision for jets etc. Just a plunger sized hole 

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Something seems vey strange, the carb needs 4 fuel jets to work properly (plus the two air correction jets). You definitely need low speed jets for both the primary and secondary barrels. As far as I can tell, only 3 of the 4 fuel jets are fitted to your carb. Obviously the main jets are installed and the air jets as well, and there will be a low speed jet installed on the secondary barrel but you need a low speed jet (sometimes called an idle jet) on the primary side as well. From the factory your carb would have had a special solenoid that incorporated the low speed jet. The picture below shows how they work. Unmetered fuel enters through the holes in the side of the jet, the tapered end of the jet seats and seals against the carb body (this is the area that you described as a plunger sized hole). In your version of the carb this hole is not there to accommodate a plunger it is supposed to accept the tapered end of a fuel jet. Metered fuel exits via the calibrated orifice and ensures the correct amount of fuel is delivered to the primary low speed fuel circuit. Without this jet there will be way too much fuel delivered at low engine speeds  (up to about 3000 RPM). Would it help if I took mine apart and snapped a few pictures for you?

 

idle solenoid.jpg

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This picture of the secondary side of the carb may help as well. The red arrow shows the fuel pathway inside the carb and you can see that the low speed jet is in the path of the fuel flow and controls the amount of fuel delivered. Pull out the secondary low speed jet and have a look at it, you will soon see how this works. The primary jet and the jet holder is physically larger than the one fitted on the secondary side but works exactly the same way. 

If you want to get really carried away have a look inside the primary barrel above the butterfly and you should see a row of small holes. These holes are called transition ports and this is where the fuel is flowing to. The fuel delivered to these transition ports must be precisely metered to ensure the correct air/fuel ratio is achieved and this is the purpose of the low speed jet.

20200726_201444.jpg

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16 hours ago, 1963 AP5 said:

Something seems vey strange, the carb needs 4 fuel jets to work properly (plus the two air correction jets). You definitely need low speed jets for both the primary and secondary barrels. As far as I can tell, only 3 of the 4 fuel jets are fitted to your carb. Obviously the main jets are installed and the air jets as well, and there will be a low speed jet installed on the secondary barrel but you need a low speed jet (sometimes called an idle jet) on the primary side as well. From the factory your carb would have had a special solenoid that incorporated the low speed jet. The picture below shows how they work. Unmetered fuel enters through the holes in the side of the jet, the tapered end of the jet seats and seals against the carb body (this is the area that you described as a plunger sized hole). In your version of the carb this hole is not there to accommodate a plunger it is supposed to accept the tapered end of a fuel jet. Metered fuel exits via the calibrated orifice and ensures the correct amount of fuel is delivered to the primary low speed fuel circuit. Without this jet there will be way too much fuel delivered at low engine speeds  (up to about 3000 RPM). Would it help if I took mine apart and snapped a few pictures for you?

 

idle solenoid.jpg

Yeah if it's easy that'd be much appreciated if you could! 

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No worries, will do.

In the mean time this diagram may be useful to you. It describes how the fuel circuits in the primary barrel work. I think you are probably experiencing problems with the progression circuit. You can probably get it to idle OK but it will cough and splutter as you open the butterfly and the engine transitions to the point where it will run nicely on the main circuit. Sorry if I am adding way too much info but I will try to describe how this works.

At idle with the throttle butterfly closed (well nearly closed) the fuel mixture is controlled by the idle mixture screw.

As you open the butterfly the progression holes (I called them transition ports in by previous post) are uncovered and exposed to vacuum pulling fuel into the airstream. The amount of fuel delivered to the progression circuit is controlled by the low speed jet (idle jet). The progression circuit remains active up until about 3000 rpm and after that the engine will be running on the main circuit.

Without the low speed jet metering the fuel in the primary progression circuit I think it will just pour fuel through the progression holes.

Detailed photos of my carb to follow.

Fuel circuit diagram.PNG

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Here you go.

As shown on the pictures this is how my one works.

The low speed jet and holder on the primary side is an aftermarket item that is designed to be used in place of either the two stage jet (on late model versions like mine) or the integrated solenoid/idle jet (on early versions like yours). It is physically much larger than the jet fitted to the secondary side and I have included a picture that shows the size for reference.

On my carb the fuel supplied to the progression circuit (low speed circuit) must pass through this jet before it gets to the progression holes in the primary barrel. This is important because without this jet you simply can't tune the amount of fuel delivered to this fuel circuit. I think I made a mistake in the previous post and I got the direction of the fuel flow through the jet wrong, it actually enters through the end and exits through the holes in the side.

I also took a photo of the carb body looking inside the area where the jet is installed. It does look suspiciously like a plunger sized hole but I am pretty sure your one should work just like mine and it will need a jet fitted in this location.

As far as I am aware the only difference between the early model version like yours and the later model version fitted to my car is the separation of the fuel shut off solenoid and the idle jet. On the early version, the jet and solenoid were combined in one assembly. On the late model carbs they relocated the solenoid and changed it to a plunger type and  fitted a fancy 2 stage idle jet in the low speed fuel circuit. I don't think the plunger type is supposed to be fitted to the early version of the carb.

I also checked the jet size and it's a 60.

Fuel flow diagram.jpg

Jet and holder.jpg

Jet physical size.jpg

Jet removed.jpg

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