i am greg. i have a 74 cutlass supreme. it has a 350 rocket and runs great when it starts. the problem it has is when it sits over night, it loses all the fuel out of the line.i replaced the fuel pump,and still has the same problem. i replaced the fuel lines , and it still has the problem. anyone have any other ideas? i am affraid of burning my starter up from cranking it so much to get fuel to run.

 

 

well my nightmare begins, the starter and battery are now bad and need replaced. off to the parts store i go. maybe they can tell me why fuel lines are losing thier prime?

 

I'm assuming your running a Quadrajet? Your next step is to verify there is no fuel in your carb by removing the air cleaner and looking down inside the carb to see if you have 2 streams of fuel shooting in there when the engine sits over night.

Your other issue could possibly be the choke not operating correctly. Do set your choke properly by pumping the gas 2 times prior to starting a cold engine?

 

yes i have a quadrajet carb. it was rebuilt a few years ago. i have a glass fuel filter from summit so i can see the fuel. it definatly is not getting fuel until i crank it a few minutes. i just replaced my battery and both cables, and a new starter. the fuel pump and lines are only a few months old. once it gets the fuel, it fires up and runs good.

 

i have a manual choke. the automatic stuck shut ,so when the carb was rebuilt i switched it over.

 

Which fuel lines did you replace? All of them? Did you replace the rubber lines in the rear that go from the hard lines to the tank inlet/sending unit? You would have most likely had to remove the tank to get to those lines easily. If you didn't replace those rear lines I'd bet they are cracked and sucking air and letting the lines drain when the car sits.

 

Looking at the fuel filter is not going to tell you if there is gas in the carb or not. Like I said, next time before you go to start it cold, remove the air cleaner, look into the carb and operate the throttle to see if it squirts 2 streams of fuel.

 

yes i dropped the tank and replaced them from front to back. new steel lines and new rubber lines , the only line i did not change is the one that goes to the black canister. could the sending unit assembly be bad? i noticed the gas gauge does not work properly. it floats all over the place and mostly sticks on the full mark.

 

i took the air cleaner off,and looked for gas this morning. it only spit a little bit of gas out.it wasn't enough to do anything. after i crank on it and saw fuel in the filter, i look at it again, it had the two streams it should have when pumped it. i reached in and it fired right up. i was wonndering about the sending unit causing the problem.

 

One of the issues with Q-Jets is fuel leaking out of the bottom of the bowl into the manifold. There are 2 places where holes were drilled for passages and then soldered. Most folks will clean this area real good and then apply J-B Weld to reseal. Hope this helps.

 

This gets retold a lot. Unfortunately, it only applies to the first couple of years of Qjet production when the well plugs were pressed-in sheet metal plugs. Since the mid-1960s Qjets have used spun-in aluminum plugs in the well and they do not leak. Doug Roe got the entire world spun up about this in his Qjet book, but I've NEVER seen a leak from one of the spun-in plugs.

 

well i guess i'll pull the carb off to see if there is gas in the intake, or any signs of a leak.

 

i took the carb off this afternoon, it has no signs of leaking. inside the intake was damp, but i assume thats normal. there was no puddles of gas or anything. i replaced the carb base gasket. i don't like to reuse old gaskets.

 

Just thinking here - maybe check the float. If it sinks while the engine is off, it could pull the needle off the seat and allow fuel to drain out of the float bowl.

The fuel has to go somewhere, and if it's not leaking externally, it may be going back into the tank.

 

Even if the float isn't sinking, simple evaporation of the fuel causes the level (and thus) the float to drop, opening that pathway. Now, replacing the stock fuel filter with the in-line filter compounds the problem since the stock filter should have a check valve built in to mitigate this problem. Sounds like the combination of the aftermarket filter and a weak pump is causing this.

I have a similar problem in my 62 with the E-brock carb. If the car only sits a few days or a week, it starts fine. Longer than that and evaporation empties the bowl. The pump is weak and I end up having to prime the carb to get the car started. Of course, the solution is to drive the car more frequently.

 

Wow!! Thank You Joe for the great welcome to the forum!! Nothing like a Newbie getting reamed by the Big Rocket. However, I'm not easily intimidated!

Greg's gas is going somewhere over night and it's not just evaporation. As Fun71 said, once the fuel leaks out and the float drops, the fuel in the lines will drop to the fuel level in the tank. So where is the leak?? Today's gas will show less indications of a leak than gas from years gone by.

So Joe, You've "NEVER seen a leak...etc.....". Well I have. And I'm not going to roll over and let over 50 years of working on Q-Jet's get censored by you! My experience comes from hands on work and not from reading a book!

Best to You..........Steve

 

i think fun 71 is right.i was laying under the car today, debating on dropping the tank again, and i kept hearing a dripping noise. i listened for a while,then put my ear on the tank, and that is where it was comming from. now i know why my fuel lines are empty in the mornings. now i need a solution for the problem.

 

Holy Crap !

 

"Reamed"??? Heck, that wasn't even a pilot hole...

Look, is it POSSIBLE that the well plugs can leak? Yes. Is it LIKELY that this is the cause of the OP's problem? It wouldn't make my top ten list. Again, the leaking well plugs really applies to the pre-1968 Qjets with the pressed-in sheet metal plugs. GM fixed this problem with the spun-in aluminum plugs starting in 1968.

And sorry to be so brutally frank, but if my prior post offended you, you really need to grow a thicker skin. There's a lot of info on the web that gets repeated out of context and once it's repeated often enough, people start believing it as absolute truth in all situations. My mission is to help stop "truth decay".

 

What is your recommendation for " truth decay " for I have a lot of it .

I guess everybody interprets what they read differently , because I just could not see anything wrong with what you said .

 

Unfortunately, if you ever read the letters to the editor of major newspapers, someone is ALWAYS offended by something. The alternative is a pretty bland existence. No one has ever accused me of being politically correct, and I'll definitely never run for public office because of it.

 

Ya, that's what I said too after I posted it. So, my bad along with apologies to Joe and the forum. By the way how did you know my skin was thin? Heck, when I wake up after working on cars I got all kinds of bruises on my hands and arms. I'm working on the last year of my 6th decade, so I guess it comes with the territory.

Once again....Steve

 

No biggie, Steve. Glad to have you here.

 

I would suggest you replace the GLASS fuel filter with something less likely to fail. Never been a fan of those, seems to be a disaster waiting to happen. Might not fix your leak but might save the car one day.

Mike

 

No big deal Steve . I'm no angel either .