VCCA Home Forums TECHNICAL - GENERAL Mechanical - Engine, Trans, etc Newly acquired "35 Standard won't run

I brought home my newly acquired '35 Coupe this past weekend. The engine was lightly stuck but moved quickly with a pry bar in the starter ring gear teeth. After new plugs, points, condenser, changed coil and carb, and finally the starter, it starts and runs for a few seconds and dies. On a couple of occasions it has run for as much as 1/2 minute. At first, it surged for the time it was running. That has gone away and it seems to run smooth, but will not rev up. It acts like it is struggling to keep running, then dies.
Timing has been checked and reset. Vacuum advance holds vacuum. The replacement carb came from my, perfectly running, other, '35 Standard coupe.
Any ideas??

Mike

When it dies is it running out of gas or has no spark at the plugs/

Based on previous experience, clean the points. I have had too many "new" points that probably were "on the shelf" for years have a very thin layer of corrosion that is easily removed with even a crisp dollar bill.

These are old stock Delco Remy points. I'll give them a little shine and see what happens. Thanks for the tip.

Mike

Gene,
I am using a gravity flow nurse tank so I think my fuel supply is adequate. I have no reason to think I am losing spark. For the few seconds that it runs, it is at a fast idle and is not affected by the throttle position.

Chipper,
I knew it was a ridiculous notion that $1 bill would solve my problem, so I used a $20. It didn't help. Could I borrow a $100?

Mike

I could be clear out in left field but there's one particular synapse that won't shut up that keeps screaming "coil" at me considering the carb is a known good substitute.

Tiny,
I am using a coil that ran good on my 1936 truck.

Mike

In noodling this problem, I keep coming back to something electrical. Ignition switch? condenser? coil? or wire connection? rotor? cap corrosion? ground? Once you find the cause it will be a slap to the forehead.

It seems strange to me that throttle position does not affect it.

Hi Mike

I've seen this exact thing happen myself,
I just can't remember for sure what caused it! 🙂

I THINK it was a condenser or/and coil problem as suggested by those above.

Can you temporarily add a electric pump to the auxilliary tank?

I think the gravity feed might be the issue.

Jon.

This is a really out-of-left field question. Is the gravity feed system properly vented?

I had a fellow VCCA member who had set up a gravity feed gas supply to temporarily run the engine in a Model A. One evening our VCCA chapter was at his place for a meeting. He was describing the exact same symptom. The engine would start fine but only run and 20 seconds. Throttle movement did not affect anything.

I looked at his one gallon rectangular metal can for the fuel supply. He had soldered an outlet line into the cap. He had a make-shift hanger to hold the can upside down about the same height as the cowl fuel tank in the Model A. I asked how he vented it. No response. Just a sheepish look.

You could try the carburetor from your other '35. Or dribling gas thru he air horn while trying to keep it running. Perhaps the present Carb. is not letting gas flow through.

The reason I think gravity feed might be the problem:

(A) 1971 Pontiac 455 H.O. (high output - read as "thirsty") with fuel pump fuel seat orifice 0.135
(B) 1928 Chevrolet 4 cylinder with gravity feed fuel seat orifice 0.140
(C) 1935 Chevrolet 6 cylinder with fuel pump fuel valve seat 0.076

Note the difference in fuel valve seat orifices for gravity versus pressure pump.

Using gravity, the fuel valve seat in your W-1 flows approximately 30 percent as much fuel as the carb for the 1928 4 cylinder.

Jon

If the addition of an electric pump is not an option, maybe you can put an air fitting in the tank vent, and pressurize the tank to about 4 psi.

Jon

Well, well, well. It turns out that when mice have been living in your exhaust system for almost 60 years, they leave a lot of stuff in there. It is a miracle they never moved into the manifold or a cylinder with an open valve.
The engine was lightly stuck but I was able to free it with a pry bar on the starter ring gear. I turned it a full turn after adding some ATF and acetone to each cylinder. The starter turned it easily with the plugs out. I had also bounced each valve with a dead blow hammer before I tried to turn the engine.
Once I had checked the boxes and hit the starter, I got a sputter pretty quick. I thought I was about to go for a ride. That was Sunday. I didn't work on it much yesterday or this morning. Monday, Tuesday and this afternoon were spent chasing a problem that I think I should have caught onto much sooner.
As soon as I disconnected the exhaust pipe, it started and continued to run.
Thanks for all the input.

Mike

You guys are great.
I had composed a reply to Gene and Chipper that went into more detail about the things I had tried. That post disappeared into the ozone so my replacement post was more brief and less informative. THANKS again.

Mike

Wow! That was a good find! I never would have thought about a plugged exhaust.

That was it!!

Now I remember!

My sister-in-laws Hyundai completely plugged the catalytic converter and ran exactly as you described.
I found the problem with a vacuum gauge.
A wrecking bar up the end of the converter got her going again.

Very sorry I couldn't help you due to my obviously diminishing memory. 🙂

I have had clogged exhaust problems before but the engine would run at idle for 10 or 15 minutes or if you could get from idle to 2500rpm quickly it would keep running until you tried to drive. The muffler got the 5/16" drill treatment while a new muffler was acquired.
Tony

Glad you figured it out. That particular synapse never fired. I'll have to train it better.

The old potato up the tailpipe trick!

Glad you found it!

Jon

I might have to start hanging out with a smarter crowd. But where will I find them?
Jon, You could have come to help, instead of just sitting down there in Eldon and thinking to yourself what a dummy I was.

Mike