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Not getting fuel to carb??

6K views 8 replies 4 participants last post by  Goat Roper 
#1 ·
Hey guys I'm new to this forum. I've owned a 70 GTO since 1992. I was 21 and drove from TX to KS to pick it up. The car was mostly complete, but missing motor and Trans.
For the last 24 yrs the car is mostly parked in the garage. Every few months I'll crank it on and go for a drive. I went out last week and poured little gas in carb like always, but this time it wouldn't stay on.
It usually takes a while for gas to get up to carb from the tank, but No go this time? The car does start w/ little gas in carb, so not a spark issue. I noticed after several attempts fuel filter empty. So, I changed the fuel pump blew out the lines w/ air just in case, changed filter, But it still does same thing it runs then when gas in carb goes out it dies and won't start back up, unless I pour more gas in carb. Any ideas?? I thought for sure it was fuel pump, since it was 24 yrs old.
 
#2 ·
OK, I'm not implying that you are not a smart guy, but do you have gas in the gas tank? No lie, had a guy who swore he gassed up his car, the gas gauge read it had gas, it fired up when you put gas down the carb - so I replaced the fuel pump. Car would not run. Pour gas down the carb, it would fire. Learned later from the guy that his gas gauge did not work, that was a clue. So I put a couple gallons of gas in the tank and the car fired right up. Someone had stolen the gas out of his car during the previous night.

Did you install the fuel filter in the correct position. Fuel filters typically have a flow direction, in & out. With some, if you install it reversed, no fuel can pass through and it will act as a plug - I've done it myself, sad to say, you just get in too much a hurry and crap happens.

May be a stuck float/needle & seat - not opening and creating a back pressure so no gas flows. Todays ethanol laced gas can destroy these. I'd go for a carb rebuild just to ensure I have the proper needle & seat that is compatible with the ethanol gas.

It could be a collapsed rubber line, inside where you can't see it. You said you blew through the lines, this will inflate rubber hoses. Drawing through will collapse them. Check for any splits or holes in the rubber lines at the tank as well as any at the fuel pump that might simply be drawing air and not gas.

It could be a collapsed/plugged up "sock" which is at the end of the pick-up tube in the gas tank.

But FIRST, I would simply test the fuel system a section at a time. Undo the line that goes into the fuel pump and see if you can draw gas through it. If you can, reattach the line and undo the line on the other side of the fuel pump, the pressure side. As long as the car is cold, pull the coil wire so the engine won't fire, undo the line at the carb, place the line into a small can/container, like a vegetable can, and have someone crank the car over. You should see gas coming out the line and going into the catch can. As soon as you do, stop, you don't need a lot of gas. Dispose of the gas, reconnect your coil wire so you don't forget about it.

If you have gas up to the carb, it is the fuel filter or the carb itself.

If you don't have gas at the carb, then you may have a defective "new" fuel pump. There is an eccentric on the timing gear that the fuel pump arm goes underneath. It operates the arm up & down. You usually have to fight it a bit to get the fuel pump in position - unless you get the eccentric on the low side, but I never get that lucky and I'm too lazy to find "that spot", so I simply struggle to get it in position and bolt it down. I don't think you can install the fuel pump arm over the eccentric, but then again, I never purposely tried it either. Did you happen to match up your old pump with the "new" pump to make sure it was correct? :thumbsup:
 
#3 ·
Thanks Jim, I did replace all rubber hoses,forgot to mention that. My gas gauge reads 1/2 tank, and I can hear gas splashing around when moving the car side to side. I went ahead and added a gallon more just in case, but didn't make a difference. I will check the hose near the gas tank and change carb, just to see what happens?
I previously had a Holley pump (24 yrs old) I replaced new pump w/ stock Carter. 70 pump is very distinctive and everything lined up. Steel line to carb was right on the money.

Maybe it's the carb, I'll give it a try.
Thanks again.
 
#4 ·
Jim,
I believe it is the Q-jet needle seat like you said. I tried your suggestion of disco coil wire and disco fuel to carb. My daughter cranked it and here comes the fuel! I got my Holley out but, didn't have correct length bolts. So short of some longer carb bolts, I have a feeling this is going to do the trick. I will keep you posted.
 
#5 ·
OK, good news. You at least narrowed it down to the carb. Seeing the carb has been on there all these years, it is most likely due for a freshen up. If you do decide to rebuild it yourself, make sure you also get a new float to go with the carb rebuild kit. Verticle number on the side of the main body will get you the correct parts you will need from any of the online Q-jet suppliers. :thumbsup:
 
#6 ·
Jim, that did it. I put the old Holley on and she fired right up. Thanks for your help! I wouldn't have thought about the carb.
Guess I have to start looking for a good Q-jet rebuilder. I love the way those big secondaries open up when you stomp it.
 
#7 · (Edited)
You could try rebuilding it yourself. Even if you don't, you should have the best reference book out there on rebuilding/modifying Q-jets which is Cliff Ruggles' book:

How to Rebuild and Modify Rochester Quadrajet Carburetors by Cliff Ruggles, Paperback | Barnes & Noble

Cliff is the guru of Q-jets with a nationwide great rep. He also sells rebuild kits (very affordable) and other stuff for Q-jets. His kits are SO much better than what you get at your local auto parts store, which contain generic parts, usually Chevy oriented despite the box saying for Pontiac.

Cliff also has a going business rebuilding Q-jets and customizing them for your particular engine setup. His phone is 740.397.2921. (No, I don't know him but am a happy customer.):thumbsup:

His website is: http://www.cliffshighperformance.com/
 
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