1940 Series 90 8Cyl hard start?

[scot]

Hello,

1940 Series 90 with the straight eight two barrel carb. If the car sits for a few weeks without starting it I have to crank it forever to get it to fire up. If I start it every few days, a few pumps of the throttle it she fires right up.

Any suggestions?

Thanks,

Scot

[Guest rsd9699]

Drive your Olds more often and it Will start easier and will keep the battery charged up.

Otherwise, use gasoline without ethanol (alcohol).

Or use a mix of 90/10 local pump gas with diesel to keep the fuel from evaporating and/or draining back into the gas tank.

Or add an electric fuel pump to prime the system for a few seconds prior to trying to start your engine.

Ron

[scot]

Thanks for the ideas Ron.

I would love to have the time to drive the car more often. Maybe I will try a bit of diesel in the gas like you suggested. As for the electric pump. Hmm, definately not original equipment! Not that I show the car, but I try to keep it as original as possible. Do they even make a 6 volt electric fuel pump?

Thanks,

Scot

[Guest rsd9699]

What - you are not using it as a daily driver - ha ha.

Yes they do make 6 volt fuel pumps. Original - not at all but easy to "hide" and takes the strain off the electrical system and the frustration of repeated starting attempts.

Todays cars with fuel injection actually run the electric fuel pump a few seconds to pressurize the system to allow for that instant start as you turn the key.

But the gasoline of today is not your father's gasoline. Gasoline in the olden days had more oil in it and as the oil refining methods changed the oil was reduced especially after they discovered "cracking". The gasoline is thinner so to speak and readily evaporates. Adding either diesel or transmission fluid will thicken the oil and slow the evaporation. I personally use diesel but I do use transmission fluid on the "road" where diesel is not available. It also tends to stop dieseling in high compression engines and vapor lock due to hot weather and hot engine compartments.

Happy Oldsmobiling

Ron

[scot]

Well, Tues. I filled the tank with gas and put diesel in with it. Just went out (Sat) to the garage to see how she would start. Still had to crank and crank, Pumped the peddle a number of times. Finally fired up. Shut it off and crank again and she fires right up.

Is it possible for the fuel to be draining out of the float bowl?

Thanks,

Scot

[Guest rsd9699]

Yes - anything is possible.

1) Have you verified that you have a good solid stream of gas output by the accelerator pump? The pump may be dribbling a little gas with each depression of the accelerator pedal thus after ten pumps or so you have enough gas to finally start.

2) If the choke is automatic - depress pedal to floor 3 times to allow choke to set (check that it is nearly closed) and provides fuel for a cold start.

3) Manual choke - you pull it out all the way and make sure the choke plate is nearly closed then pump 3 times.

4) If no fuel is discharged then pull the top of the carb and see if there is fuel present. If fuel is present - accelerator pump is at fault or the chambers are plugged up - some have a check ball - is it free or corroded in place. No fuel present or very little - then fuel is leaking through a crack or a porous cavity. Fuel can not flow back wards through the system without there being something at fault

Process of elimination. They were not hard to start new or they would have never sold a car.

On the original accelerator pumps, some were leather seals and may have taken a set with out gas and not being exercised - soak in oil and work leather to expand it. Others had a diaphragm and it may be broken - just replace it.

Shop manual will assist you in trouble shooting this and other problems.

Let us know what your plan of attack is or if you have more questions.

Ron

[scot]

Ron,

Thanks for the detailed trouble shooting guide. I will go through the steps and let you know what I find.