Car does not start after sitting a few days. Fuel pump?

Check the BATTERY. If it doesn't have the proper cranking amps capacity it may be cranking the engine slower than it should. I've run into this a few times in the past. Engine sounded like it was cranking over normally, but unknowingly was slower than it should be. A new battery fixed the problem. On something that sits for more than 2-3 weeks I don't WANT the engine to start too quickly as dry starts are the BIGGEST cause of wear on any engine. I crank my engine for 15-20 seconds at a time, usually twice, before the oil gauge starts to move. Then pump the gas to start.
Just my opinion.


Tom T.

 

Thats true. I noticed when I do start it with the starting fluid it starts right up and sounds terrible, rattling, clicking for a few seconds before oil pressure builds up. Low battery, low cranking speed, not enough oil pressure or fuel pressure. Makes sense. I put it on the trickle charger last night and it cranks much much faster now. That may be part or even most of the problem. Going to check my fuel filter as well, just replaced it recently but maybe got it in there backwards.

 

Interesting.

If I hear a sucking sound what problem does that indicate? and the fix?

 

There is a vent hole in the cap, or a vent in the tank (not sure what they used in your LeSabre).
When the vent hole is blocked, a vacuum is created when the fuel pump is pumping the fuel from the tank.

Like I said: Remove the cap (so air will enter the tank) and try to start the car when it has been sitting for a few days :TU:
It's always worth the try, it's a free test :beer

 

will do.Thanks.

 

Have you tried using a long rubber line (feed line from tank) on the fuel pump to a one or two gallon jug of gas. This will tell you if you fuel pump is good, if the car start up correctly. If it does, I would do the same thing from the rubber feed line coming out of the tank. This will check the steel feed line from the tank to the pump. if the car starts correctly at that point. I would say you have a problem in the tank. I am thinking the pick up in the tank is the cause.

I didn't read the whole post, sorry if you all ready tried this. :idea2:


Ron

 

pretty smart.

 

im about where tech8 is at, pump a few times, and turn it a couple times. then i hold throttle @ 50% open, and turn it over till it fires up. my 70 lesabre came with the owners manual (believe it or dont) and the manual actually says that if youre having trouble starting it after the engine is warmed up, hold the pedal halfway down and turn it over till it starts. obviously this isnt a cure for your problem, just my $0.02

 

Same problem here on my 69 Riviera.

The difference is I have an electric fuel pump, except mine will start after a minute or so.

Same symptoms as everyone else. It must be evaporation. I even installed a little check valve in the fuel line near the carb. No change.

The car runs great after it starts.

 

after thinking on this quite a bit, i would definitely go for the bowl floats first. when you rebuilt the carb, did you replace them, or just clean them off and re-use them? probably where i would start with it. if you have a helper, have them turn it the key while you tap the bowl with the plastic handle of a screw driver.

 

Kinda late getting in on this but I had a similar issue. I epoxied the carb bowls, replaced the fuel pump and still the same. After checking everything I found the short rubber hose that connects the tank to the gas line was cracked. replaced it and now everything is fine. I think it had hirline cracks and was allowing air to suck in rather than fuel.

 

Clamp off the fuel return line off the fuel pump. You could be bypassing most of the gas straight back into the tank.

 

X2 I hate when it fires right away with no oil pressure yet, ticks me off:af:

 

I had the same problem with my 68. After sitting for a few days or more, it would not start without an excessive amount of cranking unless I dumped about a tablespoon of gas in the carburetor. Then it would fire up.
I decided to see if the 10% ethanol gasoline was the problem. The only problem is we do not have non-ethanol premium around here, only 87. And my car will not run on 87, it barely tolerates 93. I found a source of LL 100 octane non-ethanol and put 5 gallons in with the approximately 10 gallons of 93 premium that was already in the tank. The car was already warmed up when I did this so I drove around some to get the 100 octane mix into the carb. I parked the car and let it sit for a week. When I started it a week later, it started easier than it used to but still not perfect. I added another 5 gallons of LL 100 octane and with the new mixture it starts great.
I am now up to an almost 100% LL 100 octane mixture. The car can sit for a week or more, and I just turn it over for about 5 seconds two times to get the oil pressure up a little, pump the gas pedal twice, turn the key and it fires right up. And it stays running, it doesn't stall like it used to do.
Now if they would start selling 93+ non-ethanol around here I would really be happy...

 

what compression?

 

Stock 10 to 1, un-rebuilt, 91,000 mile original 400.

 

Whhere you get the filter and gasket from?