1975 Chrysler New Yorker Brougham

[75LandYacht]

What carb is in it?

 

[bvberserk]

What carb is in it?

it should have 4bbl thermoquad, but I didn't have a reason to verify, since it was running a-ok

 

[75LandYacht]

it should have 4bbl thermoquad, but I didn't have a reason to verify, since it was running a-ok

Reason I ask is thermoquads can get Heat soaked from the engine heat causing the fuel to boil off in the fuel line, so when you go to start again the Fuel pump will need to fill the line again leading to the carb causing that Hard start issue. Just my thoughts. Could be something else though, others here may have some input as well.

 

[Robert Saigh]

^^ John: Don't Thermoquads have a tendancy to Leak onto the manifold?

 

[75LandYacht]

^^ John: Don't Thermoquads have a tendancy to Leak onto the manifold?

They can Bob, if the center plastic section of the carburetor is warped it can lead fuel.

 

[thethee]

Don't forget about the primary jet wells when it comes to leaking

 

[commando1]

Or the TQ being a POS to begin with...
@73 T&C will agree with me.

 

[bvberserk]

Or the TQ being a POS to begin with...
@73 T&C will agree with me.

Won't confirm this after first start failure

 

[bvberserk]

Well, I found out that it is pretty hard to troubleshoot this stuff alone anyway, first I noticed that metering rod is stuck/not moving, but that was an easy fix - unscrewed it and released, screwed back. now it moves freely. Somehow I rode fine several times and didn't notice anything (though MPG was not the best I guess with metering rod stuck). However main thing I noticed - I don't see any fuel squirting. It is wrong, correct? What shall I check next? disconnect fuel filter and check if there is fuel there? Try to crank engine and verify fuel pump is pumping fuel to the floor/bucket (with fuel line disconnected from filter)?
I would appreciate any ideas

 

[thethee]

Does it still run? Should be squirting fuel from the center nozzles. Looks like a broken accelerator pump. Can be replaced but have to open up the carb for that.

 

[bvberserk]

Does it still run? Should be squirting fuel from the center nozzles. Looks like a broken accelerator pump. Can be replaced but have to open up the carb for that.

No it doesn't run, doesn't start (another car is heard on video). Thanks, I guess I'll check fuel pump first then will look towards disassembling carb

 

[75LandYacht]

No it doesn't run, doesn't start (another car is heard on video). Thanks, I guess I'll check fuel pump first then will look towards disassembling carb

Thermoquads can be very temperamental. Do you have access to another carburetor? Even an aftermarket one?

 

[Jon O.]

Pull off the fuel line where it goes into the carburetor, crank just long enough to see if fuel comes out. If it does, it's a carburetor issue. If not, you have a fuel pump/gas tank crud issue.

 

[bvberserk]

Pull off the fuel line where it goes into the carburetor, crank just long enough to see if fuel comes out. If it does, it's a carburetor issue. If not, you have a fuel pump/gas tank crud issue.

Thank you for explaining even basic things. Although I do understand some carb principles, it is always better to have some support
As for the update today - was able to start the car (in 4 hands) - son cranked it while I was trying to see squirts through opened primary/choke door - and although I couldn't see any squirts (strange) it started up after several tries.
* When I tried to close the choke door - it ran more rough even trying to stall. With door wide open it ran better
*It ran really smokey
*When getting warmer it still ran unstable, trying to stall when idle and OIL lamp was blinking on idle

So my conclusions are: curb idle is too low -car should run stable with no OIL lamp blinking.
Probably high Idle should also be higher
Mixture is too rich - need to tune idle mixture to run leaner
I'm going to get a tachometer to configure IDLE on weekend.
Do I need to tweak anything with ignition at the moment?
Anyway I'm happy it started - it means that ignition and fuel delivery work well, nothing is totally broken
Though definitely need to know my own carb better - need to see those squirts

And sorry for rookie English, I don't know all the carb parts yet - I'm pretty sure primary/choke door is not a primary and not even a door

 

[Jon O.]

Your idle will probably come up on its own when the carburetor is set right. Get a vacuum gauge to set the mixture screws by, then use tach to set idle speed. If it ran fine, and is all of the sudden running rich, the first thing I would check is if the floats move freely and still float. Then if the needle and seat seals. Do this before you turn any adjustment screws. I don't know about a thermoquad, but there are some Ford carburetors I have ran without a top on them to determine if the fuel bowl was overflowing/ needle and seat not sealing.

 

[bvberserk]

Continue getting familiar with NYer. Was concerned about blinking OIL lamp that I haven't noticed earlier. Checked the oil level and it was too high and was superthin like water. I suspect it was thinned by gasoline. Am I supposed to change oil every time I have starting issues? So there was no another option as to change oil.
Oil filter was extremely tight, I was really afraid of destroying it. Got a bit smaller filter - it is used both in my Intrepid and Town&Country.

 

[bvberserk]

As for starting, today is 50F and after sitting for 2 days car started like a champ from the first engine rev, without any priming/pumping - like modern injector car.
But carb tuning was harder than I expected when watching uncle Tony's videos - have some random misfire, which causes vacuum gage bouncing around. Anyway, when completely warm, engine has about 20 inches of mercury vacuum, I started with typical 2.5 revs mixture screws and tweaked a bit leaner, since it was not clear whether screwing/unscrewing causes any vacuum changes.
I'm still going to open up the carb and check accelerator pump, as during WOT test it almost died several times. I wonder how is pump movement looks like? I assume as it is operated by vacuum (and spring) it can be moved by hand freely - mine is not moving - or moving like 1/5" (5mm).
And also what is the correct way to measure vacuum? I used carb vacuum port which is connected to Air filter housing, is it ok?
Any ideas how to track down such misfire without ODBII?

 

[thethee]

If it is in fact gas in you oil might wanna check the fuel pump, could have a leak in the diaphragm. Most of your problems seem fuel related so I'd start there.

 

[Jon O.]

There should be a little tree on the intake manifold with vacuum hoses coming out of it. You connect the vacuum gauge onto one of those hoses. There should be 4 mixture adjustment screws, one for each barrel in the carburetor. Turn one screw to the right until vacuum starts going down. Then turn the other direction until vacuum goes up as far as it will go. Then turn to the right just a little. It may take several turns to see the vacuum change. After that, do the 3 other screws. After you have them done, go around and check them all again. The shake/bounce in the vacuum needle should smooth out when you get it all set right.
If you have something in the oil, square that away first. The engine will quickly self destruct if it's contaminated. The oil will smell like gas if it is contaminated with it. Check your radiator just incase to make sure there is no oil in there.