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1939 LaSalle Opera Coupe - Carburetor Adjustment (Pics)

Started by Aeroman (Juan Ramirez), September 14, 2009, 02:23:50 AM

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Aeroman (Juan Ramirez)

Hello Everyone,

I have a question about fine tuning my carb on my '39 LaSalle coupe. I have issues getting the engine to fire up and stay on idling.  I have it all original, with the 322cui engine.  This is what happens:

Temporarily, I am using a 6V electric fuel pump.  Gas is getting up to the carb.  I turn the key, press the Starter button, and the engine cranks and fires up for a split second.  I pour a little fuel in the carb and it remains on for a few seconds.  I adjusted the automatic choke to be closed when cold.  After pouring fuel in the carb, I got it started and noticed when I keep the choke butterfly close to "closed" position, it stays on.  However, if I open up the choke butterfly, allowing more air in, it shuts off all the time.  So it seems like the increase in air is killing it.  My question is, what can I do to get it just right where the engine stays on?

I noticed there were two valve screws located at the base of the carb.  What do these represent and at what setting should I leave them at?  Two full turns out?, etc?

Thanks





1939 LaSalle Opera Coupe

John Washburn CLC 1067 Sadly deceased.

Hello,

If you can get the old girl to run with the choke closed, but not open, you have a vacuum leak. Check out the fuel pump and the rubber hose to the windshield pump, it could be leaking.
John Washburn
CLC #1067
1937 LaSalle Coupe
1938 6519F Series Imperial Sedan
1949 62 Series 4 Door
1949 60 Special Fleetwood
1953 Coupe DeVille
1956 Coupe DeVille
1992 Eldorado Touring Coupe America Cup Series

Aeroman (Juan Ramirez)

Quote from: John Washburn CLC 1067 on September 14, 2009, 09:10:53 PM
Hello,

If you can get the old girl to run with the choke closed, but not open, you have a vacuum leak. Check out the fuel pump and the rubber hose to the windshield pump, it could be leaking.

Thanks John, i didn't think about that.  I am also thinking it may be running too lean?

About how many turns should the idle adjustment screws be turned out?  There are two of them.  Thanks!!!!!
1939 LaSalle Opera Coupe

John Washburn CLC 1067 Sadly deceased.

What you really want to do is adjust each one individually, screwing it in till the rpm drops, then back the screw out till you get the highest rpm, best running at idle. You may have to do this a couple of times to get it correct.

Good Luck
John Washburn
CLC #1067
1937 LaSalle Coupe
1938 6519F Series Imperial Sedan
1949 62 Series 4 Door
1949 60 Special Fleetwood
1953 Coupe DeVille
1956 Coupe DeVille
1992 Eldorado Touring Coupe America Cup Series

Otto Skorzeny

Do that with the vacuum advance (if equipped) disconnected and plugged.

Turn the idle screw all the way down so the engine just barely runs.

Then adjust your mixture screws accordingly as John describes.
fward

Ask not what your country can do for you, but what you can do for YOURSELF

HUGE VENDOR LIST CLICK HERE

John Washburn CLC 1067 Sadly deceased.

Otto,

No vacuum advance on 39, was reintroduced in Cadillac/LaSalle in 1940.
John Washburn
CLC #1067
1937 LaSalle Coupe
1938 6519F Series Imperial Sedan
1949 62 Series 4 Door
1949 60 Special Fleetwood
1953 Coupe DeVille
1956 Coupe DeVille
1992 Eldorado Touring Coupe America Cup Series

Otto Skorzeny

fward

Ask not what your country can do for you, but what you can do for YOURSELF

HUGE VENDOR LIST CLICK HERE

35-709

#7
Problem here is, as Juan stated, and if I am reading it right, the car will not continue to run unless gas is being poured down the carburetor OR if the choke is kept fully closed once it starts.
I have to ask, will the car run normally at a higher "off idle RPM" without keeping the choke closed or pouring gas down the carb?  If it WILL then there is (at least for starters) a problem in the carburetor's idle circuit.  From the looks of everything in the pics you posted I do believe the carb needs a proper overhaul.  BUT, for a quick (and maybe temporary fix) you can try this --- if you have not played with the two "valve screws" (those are your idle mixture screws), then screw them all the way in (just until they bottom out, don't tighten them) counting the number of turns each takes (remember it) and then remove them, it should be about the same for each --- 1 1/2 to 2 turns (at least on newer carbs, I am assuming yours is about the same).  You will later do the same thing to reinstall them, bottom them out and then screw them out the same number of turns you counted before.  If you HAVE changed them, just take them out.  Blow compressed air into each idle screw hole (hopefully you are removing whatever might be plugging the idle circuit doing this), your compressed air nozzle should make a sort of snug fit with the hole.  Then reinstall the idle mixture screws 1 1/2 to 2 turns out from bottom (make it 1 3/4s if you like  ;D)  If you're lucky the car may now idle and you can fine tune it by adjusting each screw until max idle RPM is achieved based on what your idle is set at in the first place --- another screw.  If you want to get REAL fussy you can use a vacuum gauge and adjust the idle screws for max vacuum.

Having said all that, if the car will only run with the choke full on or by pouring gas down the carb no matter what RPM you are at then you are looking at a carb overhaul and/or a fuel pump problem.
 
Geoff N.   
1935 Cadillac Sedan resto-mod "Big Red"
1973 Cadillac Caribou - Sold - but still in the family
1950 Jaguar Mark V Saloon resto-mod - Sold
1942 Cadillac 6269 - Sold
1968 Pontiac Bonneville Convertible - Sold
1950 Packard 2dr. Club Sedan
1935 Glenn Pray - Auburn Boattail Speedster, Gen. 2

Aeroman (Juan Ramirez)

Thanks to you all, I'll print this out and try what you suggested.  I have overhauled the carb with a new rebuilt kit.  I made sure the float had the proper clearance using a feeler gauge.  I have that after market electric fuel pump located near the gas tank.  It is pushing fuel right through.  At first, I thought I had flooded the carb but after pouring some fuel into the barrel, she fired right up for 1 second and that was it.  She doesn't want to stay on.  ONLY when my bro-in-law holds the "butterfly" in the barrel almost closed does she remain on...and she stays on with a rather higher RPM.  So we figured that the carb isnt getting fuel for it to stay on.  Maybe I can take a video and show you what I mean!  Thanks again.
1939 LaSalle Opera Coupe

35-709

"So we figured that the carb isn't getting fuel for it to stay on."

And right you are.  In light of what you said it sounds to me like the carburetor is going to have to come back apart.  Stuck float (make sure it is free and isn't dragging on the inside of the carb), maybe piece of trash somewhere.  It is just going to take a close and painstaking look and very careful re-assembly.  You'll get it, post your YEEHAW when it happens.
;D  Geoff N.

1935 Cadillac Sedan resto-mod "Big Red"
1973 Cadillac Caribou - Sold - but still in the family
1950 Jaguar Mark V Saloon resto-mod - Sold
1942 Cadillac 6269 - Sold
1968 Pontiac Bonneville Convertible - Sold
1950 Packard 2dr. Club Sedan
1935 Glenn Pray - Auburn Boattail Speedster, Gen. 2


Otto Skorzeny

Juan,

Take that carburetor off and send it to Daytona Parts. Click on the link below my signature to find the contact information. They do a superb job.

Next, get under that car and get rid of all those spiders!
fward

Ask not what your country can do for you, but what you can do for YOURSELF

HUGE VENDOR LIST CLICK HERE

David King (kz78hy)

#12
I think you want to get it running first.  Keep the choke open some, put a screw driver in there just to hold it open.  Drip a little gas in carb and run your routine.  I'll bet it starts.  You will have to work the throttle some, but at least you can hear it run.

My two cents.

David
David King
CLC 22014  (life)
1958 Eldorado Brougham 615
1959 Eldorado Brougham 56- sold
1960 Eldorado Brougham 83- sold
1998 Deville d'Elegance
1955 Eldorado #277
1964 Studebaker Commander
2012 Volt
CLCMRC benefactor 197

Director and Founder, Eldorado Brougham Chapter
Past President, Motor City Region

Rare Parts brand suspension parts Retailer via Keep'em Running Automotive

35-709

I am sticking with what I said about that carb. having to come back apart.  Be certain that the float isn't sticking for some reason and that the needle valve is moving off of its seat when the float goes down.

Forrest's suggestion is worth considering too.
Geoff
1935 Cadillac Sedan resto-mod "Big Red"
1973 Cadillac Caribou - Sold - but still in the family
1950 Jaguar Mark V Saloon resto-mod - Sold
1942 Cadillac 6269 - Sold
1968 Pontiac Bonneville Convertible - Sold
1950 Packard 2dr. Club Sedan
1935 Glenn Pray - Auburn Boattail Speedster, Gen. 2

John Washburn CLC 1067 Sadly deceased.

Ok,

After listening to the video's, and with some experience -- and it seems this quote is still viable "90% of all fuel problems are electrical".

That being said, pouring gas down the carb should have got some response, unless the plugs are flooded. Using new, resistor plugs, might cause a problem, the new plugs are not manufactured to protect against flooding, so if you flood these new, resistor plugs (really flood them) they will not fire. So you might want to check this out.

Make sure you have spark at the plug pull one out and ground it against the  block and see if it fires when you turn the engine over.

Now back to the carburetor, rebuild it, that carb looks like it has sat for a long time. Once this happens they will still start, but won't run

Carb kits: thecarburetorshop.com

Jon provides the hard parts, that others don't. As always, this is my opinion.

John Washburn
CLC #1067
1937 LaSalle Coupe
1938 6519F Series Imperial Sedan
1949 62 Series 4 Door
1949 60 Special Fleetwood
1953 Coupe DeVille
1956 Coupe DeVille
1992 Eldorado Touring Coupe America Cup Series

Aeroman (Juan Ramirez)

Thank you, Thank you for all of your help!!!!  I am going to do a last ditch of what was suggested - opening the choke a bit, pour fuel in the carb, and see if it runs.  Most likely, I will be removing the carb and rebuilding it again.

One quick question - what is that small cover do on the top of the carb?  It covers two small holes and they are exposed when the cover is spun a bit.  Thanks again!
1939 LaSalle Opera Coupe

Aeroman (Juan Ramirez)

We got it to fire up and got it running!  Yep, we removed the carb and found some crusty stuff on the bottom of the bowl.  It was chalky - I don't know where it could have come from since I had cleaned and sealed the gas tank.  The other issue we found was the needle valve.  It was getting stuck a lot when we dropped the float down.  I blew into the fuel inlet and it wasn't allowing any air through.  I was told there is an old trick of using the handle of a screwdriver to tap the carb and getting it to work.  I have included some images:





Jets looked plugged too:











And what is this swivel tab thing used for?  Breather?


1939 LaSalle Opera Coupe

Steve Passmore

Hi Juan
After reading your post and watching your videos I was about to say I fully agree with Otto and Geoff that your trouble was  all down to the carb, Now I see they were right and you have solved it, well done. That old engine was wanting to fire, she just needed the gas down her throat. It was getting to the carb body but was obviously not getting into the venturi.
Do you plan a full restoration on this car? I think I saw a grill on ebay recently.
Steve

Present
1937 60 convertible coupe
1941 62 convertible coupe
1941 62 coupe

Previous
1936 70 Sport coupe
1937 85 series V12 sedan
1938 60 coupe
1938 50 coupe
1939 60S
1940 62 coupe
1941 62 convertible coupe x2
1941 61 coupe
1941 61 sedan x2
1941 62 sedan x2
1947 62 sedan
1959 62 coupe

John Washburn CLC 1067 Sadly deceased.

Juan,

I am trying to figure out what the "And what is this swivel tab thing used for?  Breather?" I can't make out what you are looking from the last two pictures.

This has got me baffled?

The crud in the carb was what is left when gas goes bad.

Good Job.

John Washburn
CLC #1067
1937 LaSalle Coupe
1938 6519F Series Imperial Sedan
1949 62 Series 4 Door
1949 60 Special Fleetwood
1953 Coupe DeVille
1956 Coupe DeVille
1992 Eldorado Touring Coupe America Cup Series

Aeroman (Juan Ramirez)

Quote from: Steve Passmore CLC 22373 on September 22, 2009, 05:21:13 PM
Hi Juan
After reading your post and watching your videos I was about to say I fully agree with Otto and Geoff that your trouble was  all down to the carb, Now I see they were right and you have solved it, well done. That old engine was wanting to fire, she just needed the gas down her throat. It was getting to the carb body but was obviously not getting into the venturi.
Do you plan a full restoration on this car? I think I saw a grill on ebay recently.
Thanks!  A full restoration?  YES.  Frame up, down to the bolt.  Thanks for the heads up on the grill, I'll look for it.
1939 LaSalle Opera Coupe