car won't start, carb problem?

[Krubba]

So finally got around to trying to start the bird again, last ignition fixes were grounding issues and fuel pump. Of course now it wouldn't even crank

So diagnosed the solenoid, jumpering the ignition terminal (red blue wire) to battery lead, cranks fine. Then after some testing, figured out which slots in harness are for starter neutral safety switch (slots furthest from where wires come in), and jumperes them, voila! Engine cranks!

And cranks, and cranks, and cranks. Pull off fuel hose at carb, dry. Get out my vacuum test pump, start sucking, and finally gas shows up, yay! Crank engine, spurts gas, looking good :)

Crank some more, still nothing. Pour some gas straight into carb, it fires. Then again nothing.

I also blew air through fuel filter to check if it's clogged, and it's not, so fuel must be getting all the way to the carb, but nothing into the carb? Feel like it must be something simple, but I don't see anything loose or disconnected.

And it ran fine in the spring, haven't touched carb since. Any ideas what could have gon wrong so suddenly?

[tbird]

Disconnect the fuel line at the carb and see if you get fuel at that point when cranking if so the floats must be stuck up in the carb or needle and seat is plugged.

[Krubba]

I'm positive fuel is getting to carb, pump was pulsating fuel out the hose when I disconnected from filter, which in my case screws into carb.

How do I check and un-stick floats, or clean needle? Can I just remove top part of carb leaving carb in place?

Carburetor scares me almost as much as automatic transmission :|

[RAVEN]

You can remove top plate cover of carb very simply.
A) remove air filter cannister
B) remove air filter mounting stud in centre top of carb body
C) remove the 8 slotted cover screws. 2 at front edge of carb body, 2 at rear edge of carb body, and the 4 around the centre air horn above the butterflies.
D) disconnect the small linkage of the choke by removing the spring clip or cotter pin (which ever you have)
E)disconnect the small air tube for hot air choke (again if your carb is fitted with same)
F) LIFT top cover off carb body, AND YOU ARE THERE

NOTE: this is if you have an Autolite carb.

Have fun.

[dales65]

Krubba, I live in Edmonton as well and quite familiar with carbs, if your still having problems give me a call, 780-868-5459.

Dale

[Krubba]

Wow, thanks Dale!

I'll give it a go myself first, take off the top and at least fire some carb cleaner through it. It's not an original, it's a 4300, but it seemed to be working well enough before this little hiccup.

[redstangbob]

It's not an original, it's a 4300

Sorry, 4300's don't work like 4100's, you don't run them with the top off.

[redbow]

It takes three things for an engine to run. (1) fuel, (2) fire, and (3) air. If you have fuel through(not just TO) the carburetor. And it still will not run then the carburetor is not the problem, so check to be sure that your getting fire. It's a proven fact that in 75% of cases of engines not running the carburetor is Not the problem.

Burke

[Joe Johnston]

It's a proven fact that in 75% of cases of engines not running the carburetor is Not the problem.

Reminds me of large signs in a buddy's shop.

On one wall is a sign "Most problems thought to be electrical are fuel related!"

The sign on the opposite wall "Most problems thought to be fuel related are electrical!"

[Krubba]

I confirmed spark by pouring fuel straight into carb, and engine did indeed run for a second or two, and with fuel getting to carb, it can only mean fuel wasn't getting through the carb. I pulled the carb off tonight, and split the top and bottom halves. Scary how easy that was!

Actually didn't look as bad as I expected inside, but still chased carb cleaner through every orifice I could find and gave it a general cleaning. Then quickly reassembled before I forgot what goes where, but didn't have time to try it out. But there was at least a cup of gas in the carb, so floats probably weren't the problem, maybe something else plugged up.

Hopefully will test tomorrow and report back...

[Krubba]

Tested cleaned carb today. First, cranked a bunch, but could tell something was wrong with the linkage. Went to fix and saw the carb was leaking like a sieve! At least I know fuel is getting in :\

Tightened all the screws, which felt a bit loose (guess I was tired and weak last night), and mopped up the spilled fuel. Tried it again, and she finally fired up! Hallelujah! However, she's never run so rough, and still leaks fuel right where the accelerator linkage hooks up. I'm hoping it's just a poorly connected spark plug :|

[Krubba]

Couldn't let it rest, went to try it again. Started up right away, yay, but man is it running rough! Sounds almost like a tractor. Plus, after running for maybe a minute, if that, it filled the garage with smoke and smelled like it was gonna blow up if I lit a match.

So, all I touched since this car last ran well was new oil pan and fuel pump. I took out spark plugs to make manual cranking of engine easier, which is why I'm suspecting plugs. Maybe bad connection or bad order? How does bad spark sequence manifest itself?

Any other ideas?

[Krubba]

Oh, also put a video up on YouTube, so you can hear it and see it shaking:

http://youtu.be/f9UV5lleI-g

I'm looking up the spark sequence now so I can rule that out.

To test for bad connections, can I just unplug cables at distributor while running to see if it changes the idle? Is that safe?

[BrianC]

Could be a bad vacuum leak.

[Krubba]

First, a huge thanks to Dales65 for coming by and letting me pick his brain. It was a real treat talking to face to face to someone who's gone through the same trials and tribulations!

Secondly, BrianC, you were right. I couldn't see the forest for the trees, but Dale saw it right away. I had forgotten to reconnect the brake booster. Doh! Can't even remember when or why I took that off...

Mind you, after putting that on, the motor was still running pretty choppy, and the garage still filled with smoke. But we let it keep running, and as it warmed out, the idle smoothed itself out and was soon running as well as before. Not really sure why that might be, I'll have to see if it stays smooth on the next cold start.

There was still an odd misfire, which I noticed back when I ran it before, so I'll take Dales advice and put in new plugs, cables, points and distributor cap, and see how she runs then...

Thanks again for all the tips, Dale!