IML: Starting Problems = Was: re: Alison's car

The problem with having to crank for ages is very common in carbureted cars. Those of us who drive Fuel Injected cars are spoiled by the instant start performance of an electric fuel pump leaping into action as soon as you twist the key!

In the olden days, when our collector cars were driven every day, this problem didn’t get a chance to show up as frequently, but now, when we drive them seldom, the carburetor bowl is always empty when we go to start them. There are a couple of sure cures:

Fit an electric booster pump in the gas line back near the tank, wired to a separate switch, so that it will run when you turn on the key and then the fuel pump for a few seconds before you try to start the car, thus filling the carburetor bowl before you begin to crank.

Be prepared with an ounce or two of gas to put in the top of the air cleaner lid (loosen the wing nut first, the gas will run down the screw threads and prime the engine).

But, the right way to fix this, of course, is to determine where the fuel is disappearing to, and cure that problem.

The only hitch in this git-along is that the fuel bowls are all vented to the atmosphere in our older cars, and the gas will evaporate sooner or later no matter what you do. However, this takes a couple of weeks, so it isn’t the main problem with these cars.

A somewhat more likely cause is a carburetor that has been “rebuilt” too many times, and/or left in the cleaning solution too long, so that the aluminum or pot metal bowl is porous, allowing gas to slowly seep through the microscopic pores of the bowl. If this problem is severe enough that the car demands long cranking after only a day or so, you would smell gasoline in the garage if you have this problem.

The most common cause of this is a leak somewhere in the carburetor that is allowing gas to drain into the intake manifold while the car is sitting. This is a serious problem, as it will dilute the oil in the pan sooner or later, and could even lead to a serious engine fire if the leakage is bad enough. The worst scenario is when a cylinder has enough liquid fuel in it that it balks the starter or even breaks the piston .

The way to check for this problem is to remove the carburetor, making sure the fuel bowl is full, then set it on a level surface with a paper towel underneath. If the fuel is leaking down out of the carburetor, it will show up on the paper towel in an hour or two.

Just to mention it, there is an old wife’s tale about gas being siphoned back into the fuel tank due to a failure in the check valves in the fuel pump. This is hogwash – the fuel line which connects to the fuel pump enters the carburetor above the level of the fuel surface in the bowl, so even if both check valves were bad, that could only cause the fuel pump and associated lines to drain back – it could not possibly drain the carburetor (remember the bowl is vented).

NOW< on a separate subject:

In your particular case, you mention hard starting when hot – this could be because fuel is boiling in the carburetor and spilling down into the intake, flooding the engine (but you’ve added a heat insulator, right?).

It could also be that your timing is set too far advanced, making the engine “kick back” as you start to crank it. You can tell which by listening to the starter – if it seems reluctant to turn as you begin to cranks, try cranking it with the coil secondary pulled out of the distributor cap and grounded. If then it cranks normally, your timing is too advanced.

If, on the other hand, it cranks just fine but won’t fire up right away when hot, you are probably suffering from fuel boiling – more and more a common complaint over here with our reformulated fuels, but I don’t know if you suffer from the same malady down under – is your EPA equivalent making you use oxygenated fuels too? If so, you may just be stuck with the problem. Keep the carburetor cool is the only cure, I’m afraid.

Dick Benjamin

From: mailing-list-owner@xxxxxxxxxxxxxxxx [mailto:mailing-list-owner@xxxxxxxxxxxxxxxx] On Behalf Of Harmsworth
Sent: Wednesday, October 05, 2005 8:22 PM
To: mailing-list@xxxxxxxxxxxxxxxx
Subject: Re: IML: Alison's car

Yes you are correct Dick. I got the car with the Edlebrock fitted and the original carb in the Edlebrock box in the trunk along with the original air cleaner. The Edlebrock had some pretty horrendous vacuum leaks when I first got the car & after fitting a spacer under the carb to lift it so the air cleaner would sit on it properly I managed to turn both idle screws in 6 turns would you believe. It had been running so rich it was like it was running on coal rather than petrol, leaving black sooty marks all over my driveway. It's running as sweet as ( the dogs nuts ) now. It explodes into life from dead cold although is a little hesatent to fire up when hot. Anyone got any ideas?? and if left idle for a week then I have to crank for ages to get it to fire. Lack of fuel maybe?? Thanks

Regards Peter H

63 Lebaron

----- Original Message -----

From: Dick Benjamin

To: mailing-list@xxxxxxxxxxxxxxxx

Sent: Thursday, October 06, 2005 4:31 AM

Subject: RE: IML: Alison's car

Yes, Torrance is a suburb of LA. Alison’s car previously was owned by Norm Silverman (AKA “Watchfatha”) and was a very nice driving car - I drove it. I believe Alison converted it to an Edlebrock carburetor to cure some problem with the AFB – I hope you got the original carburetor with the car. There’s nothing wrong with the Edlebrock conversion, but you might want to put the car back to original someday. There was a problem getting the air cleaner to fit, so I think the car had an aftermarket (ugh) air cleaner on it.

Dick Benjamin (who used to work in Torrance)

From: mailing-list-owner@xxxxxxxxxxxxxxxx [mailto:mailing-list-owner@xxxxxxxxxxxxxxxx] On Behalf Of Harmsworth
Sent: Wednesday, October 05, 2005 3:31 AM
To: mailing-list@xxxxxxxxxxxxxxxx
Subject: Re: IML: Alison's car

No virus found in this incoming message.
Checked by AVG Anti-Virus.
Version: 7.0.344 / Virus Database: 267.11.10/119 - Release Date: 4/10/2005