VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1912-1928 idle but no go

I think I have solved my 27 clutch problem and I'd like to give it a test run but can't get out of the shed. The engine will idle (a bit roughly) but it will not pick up revs. Justs coughs, backfires and gives up the ghost.
I have cleaned the rotor and points and there seems to be a healthy spark at each plug while idling.
The carburretor is getting gobs of fuel. I took the carburretor off and cleaned all the bits and there appears to be no trace of water or dirt. Put it all back together - same thing. The only faulty thing would be the broken paper seal between the float bowl and the carb body but could that cause any issues? What else is there to do??

Same thing with My FB 50. I removed and cleaned the spark plugs. It started and ran like a champ. Now I clean the plugs regulerly so it won't leave me stranded. Also check the plug wires to make sure they have not goten switched some how. The float bowl is open to ambiant air pressure that gasket should not cause that kind of problem it just keeps the fule from leaking out.

I'm very interested in this posting since I appear to be at exactly the same place with my '24, having done the same things i.e. cleaned up the distributor, checked all the wiring & spark, benched the carb and cleaned it (twice). My gasket on the carb to intake manifold is old. Could that be causing an air leak? What is a good way to check it?

Bill R.

a good way to check for an air leak at the carb gasket is to.
start engine and spray carb cleaner around the gasket. if the rpms change or the engine stalls. you got an air leak.

Hi,my 28 does not have a fuel bowl gasket. Some do, some don't.Doesn't seem to make a difference but it wouldn't hurt to put a gasket in. There are a few things to look at. Backfiring and stalling is an indication of fuel starvation on demand. Usually we sort this by swapping a carburetor from a car that is running well. If it persists look elsewhere. You may not have access to another car which is a problem. It is also possible that your lines are blocked and that includes the filters on the vacuum tank and the carburetor inlet.There is also the vacuum tank float. If it is perforated the float sinks and raw fuel is drawn down the vacuum line to the carburetor.It runs badly, blows smoke and dies. Beyond that the distributor may not be located correctly. Basically the car should start with the distributor retarded. It is then advanced half way so that it idles evenly. It is then fully advanced to drive.Finally is the flexible inlet pipe from the air cleaner to the carburetor in place. They don't like running without one.
Hope this helps.

All 1928 carburetors should have a bowl gasket. If for no other reason it provides the spacing for the bowl in addition to stopping the fuel from sloshing out.

OK. Thanks for the replies there folks. A few things for me to check. I have started with the plugs as suggested. They were very carboned up but they are now clean and the gap set. While I was there I cleaned the connecting nuts and posts etc. Two of the copper washers were missing.
The vacuum tank is not a problem. It was, until we hid a small electric fuel pump inside it and fuel delivery problems were over.
The air cleaner is connected Ok. Got a Donaldson aircleaner mounted up under the firewall on the inside.
It should run OK without the fuel bowl gasket but I will obtain a new one (make one?) to stop the fuel sloshing out. Were they paper or rubber or what?

What type & number of 7/8" plug are you using?A sparkplug what a fairly high heat range and long reach is needed to make a Chev run well.Too short a reach or cold a heat range will cause carbonisation of your plugs.
You should also check your float level setting,and make sure that the idle tube has not come apart.You should also check that the standpipe is intact(they're diecast and can break)as well as ensuring that the venturi is in place.
If you're running an electric pump,you may want to consider installing an adjustable pressure regulator between the pump and carby,and set the pressure to no more than 1-2psi.

Strange things are happening. Finally got the engine to pick up but it will only do so with the choke fully applied. As soon as the choke is returned to normal running position the engine dies. Weird.

I had the same problem. I had to pull the choke out to get the car to move. I took the vacuum tank apart and bead blasted the rust out of it. Haven't had a problem since then.

The float bowl gasket is made of paper gasket material.

My prediction is that the electric fuel pump will add more problems than it will solve. The only advantage to the pump is after the car has sit a long time, the pump can be used to place some fuel in the bowl for starting. It should be placed near the fuel tank.

I have also heard that electric fuel pumps can cause problems

If you can use the float in the vacuum pump to turn off the electric pump and gravity flow the fule into the carburetor you will be OK. I have found that a new gasket on the top of the vacuum pump will fix them right up. How old is the fule?
might need new gas.

I don't think the electric pump is a problem. The auto electrician who fitted it said it was a lift pump and did not exert much outlet pressure.
Your idea of the float being used to regulate the fuel sounds feasible though. I regret that when the electric pump went into the vac tank we tossed out all the other pieces, float as well. I've since learned it's not good to discard any original pieces.
What you said about old fuel might be worth checking. I did top it up with new fuel but the half tank or so had been there for a couple of years. I guess petrol loses some of its kick after that long.

When I was first trying to start my FB 50 after 50 years in storage I found several problems. One, the timing, someone had turned the distributor about 90 degres. It was firing on only two cylenders. I found top dead center with a dowel rod in the #1 plug hole and put the plug wires into the cap in the proper firing order. Two, it would run only at full choke. I soaked the carburetor in GUNK (a carburetor cleaner, not sure what product you would find where you are) for 48 hours then rensing it in gasoline. I had cleaned the carburetor in gasoline three or four times with very little if any improvement. The soaking in GUNK did a world of good. The engine ran great. Three, the plugs needed cleaning. The rough running and full choke coveres them with carbon. Now a clean them often and never have trouble anymore. A hotter spark plug would probably be better. Good luck I hope your are driving it soon.
Hutch

I'm not a big fan of the electric fuel pump. That being said, if it was causing a problem, and since he has no bowl gasket, wouldn't fuel be gushing out onto the floor if the pump was overpowering the float valve?
I will go on record that old fuel is the problem. Some of it won't light with a match when it gets old.

Mike

If you are using an ethanol in your gasoline (petrol) in Australia it will absorb moisture. It only has to absorb .5% moistuure to drop out of suspension with the gasoline. The ethanol drops to the bottom of the tank where your fuel pickup is and it will not make any difference if you add gas or not you are drawing on ethanol. You will have trouble getting the vehicle to start or run properly.
Millions of daily drivers run on an ethanol mix without problems because the fuel is changed every week but collector cars that sit for long periods will experience problems.

Our unleaded fuel down in Aus will only last 3 months now and will not start the engine after that. In 2 stroke garden implements it's even worse I believe. If topped up with new fuel it will work. A lot of car collectors I know have fitted taps to the bottom of their fuel tank and drain it after each use to avoid this problem.
Ray, throwing away a 28 vac tank float is like throwing away a hundred dollar note as they are as scarce as hens teeth now, as they often crack and the sink.
I had an electric fuel pump on my 28 coach when I bought it and it gave me nothing but trouble so I rebuilt the vac tank and did nearly 30,000 trouble free miles. A mate with a 26 coach just fitted an electric pump with no pressure reducing valve and the pump forced petrol past the needle/seat and the car burst into flame, luckily he had a fire extinguisher nearby and and it only burnt the engine and bonnet (hood in US speak) a frightening thought.
Chris

I would support Chris's comments as I also run Aussie fuel in my 28. In 30 years my vac tank only failed once, because of my stupidity of using silastic on the top gasket. Will never do that again. I run the Stewart Warner vac tank with the pressed steel top,which I believe may actually be 27, but to me its a bit more simpler that the alloy top model. Never the less I would never consider replacing the vac tank with a fuel pump. The main thing to be on top off with vac tanks is rust, which I have overcome by lining the tank with the ceramic coating as per fuel tank treatment.

Regards

Ray

What is the percentage of Ethanol that is added to Aussie gas?

You guys are all correct - fuel must be the problem. This morning I drained the fuel from the tank into a bucket (which fell over and covered the workshop floor and me with fuel. Anyway, it appears that the fuel is murky orange instead of the bright clear purplish colour it should be. I removed the fuel tank to drain the rest (The outlet is 2" above the floor of the tank and there is no drain plug.
I have also cleaned the lines and drained the float bowl. It looks like the tank floor is covered with some sort of gunge. Like a green scale. I put a heap of old chain in the tank and shook it around but it's not that successful. Any ideas on how I can clean the tank? I'd really like to get some clean fuel into the engine now. I think I was pretty unreasonable to expect the old girl to run on crap fuel. Should have checked that earlier.
And yes, I should probably have fixed the vac tank hassles before resorting to the fuel pump. We live and learn. I think old Henry had the right idea with the Model A Ford - gravity tank over the cowl. Neat.

Ray
27 was the last vac tank with diecast top, all 28's had the tin top
Chris

The stupid things we do. My fuel tank has a whole heap of greenish gunge stuck to the bottom and I wanted to remove it before reinstalling it. Went to the net and Googled cleaning fuel tanks. Whole lot of info about muriatic acid etc. but one site said use acetone and a heap of chain and shake it around. That sounded like a fine idea so I put in the acetone and a long length of chain and gave it the works for about half an hour. A flashlight reveals that there was some improvement. Now for the nasty part: a vigourously agitated chain gets tangled. It's in there but it ain't coming out. I could cut it but that will leave two feet of knotted chain in the tank. I guess it won't harm, but I'm not real keen on leaving it there.
As I said, the stupid things we do.

Hi Aussiechev.

To clean your tank I would suggest you use the petrol tank cleaner that is part of the tank re-lining system.Most major auto paint suppliers sell various tank repair systems, and if they are like my nearest retailer, they sell the individual components.Try the web site www.por15.com.au

Regards

Ray