So I tried to start her up after 15 years in the making. Original, never rebuild motor!
She cranked just fine but getting no gas.

I cleaned out the tank a month ago before the start up procedure, there was still "good looking" gas in it! Drained everything and added 4 gallons of fresh fuel. She started up as I pored gas into the 4BBL carb, but than died. Checked the fuel pump, 2 1/2 psi. Replaced fuel pump still 2 1/2 psi. Any suggestions on where else to look? All I am getting is a very weak stream of gas when disconnecting the fuel line by the carb.

There is a fine mesh screen on the bottom gas line in the tank on the sending unit. Check the rubber gas lines inline to see if any is collapsed.

Shoot! Forgot about the filter in the tank. I know I replaced it before I parked it 15 years ago, but could be gummed up, I suppose. I'll check the rubber inline connecting pieces first before dropping the tank again. I was hoping I was a little low on gas, yet, but 4gal after cleaning out the tank should be enough to start it?

I managed to get the car started up and over to the gas station on a brand new, dry tank with only 2 or 3 fills from a 2.5 gallon gas can. So I would say yes.

[b][/b]

I replaced mine with ethanol rated hose. 2ft of it was cheap.

No change: Dropped the gas tank and replace the sending unit filter and blew out the fuel lines Everything is good, but I still can't get any gas to the carb. I replaced the fuel pump. Did I put it in wrong? Could use a little help here. Maybe I got a bad pump form the parts store?

From my bad memory, factory pressure was 4.5 to no more then 5.5-6.0 lbs. But think it would at least idle at 2.5?
How i determine a bad line on a car that been sit'n a long time.
First check all hoses for dry rot/cracks. They can collapse internally when the pump puts a vacuum on them.
If that's not it.
Thinking safety 1st, disconnect line from tank at pump. Be sure to clamp line from tank so cant leak. I just use vise grips same as when replacing brake calipers. Then run a another line from pump to small gas can. See if it runs.
Had lines that had internal rust(plugging it up) along the frame rail. Outside rusty, but didn't look bad enough to replace.

Is there eccentric in place for the fuel pump, m last v8 had a electric pump. If my memory serves me right in 79 i rebuilt an engine and there was a eccentric in there somewhere for the fuel pump, maybe it was left out ?

loops my bad he never had engine apart... bet float or carb
gummed up.

Could the tab on the eccentric might have broken where it is not working the fuel pump?

That's one of the things I'm struggling with! I replaced the pump 15 years ago and I just slipped it in and it worked. I am still trying to get accurate info on what's driving the pump. Pontiacs do not have a pin like Chevys that drive it. I read somewhere there's a follower attached to the timing chain??? Or a lop on the cam?
So far I replaced the sending unit filter, blew out all the lines, blew air into the fuel line on the fuel pump. I just can't get any fuel to the carb. I bench tested the pump and know it's good. It worked before I parked the car, so I would think whatever drives the pump is not worn. I can't feel anything in the timing cover hole that operates the pump and cannot think of a trick to install any different. Frustrating!!!

does your pump look like this https://pontiworld.com.au/usgmsp/product_info.php?products_id=5175
or like this https://pontiworld.com.au/usgmsp/product_info.php?cPath=199_552&products_id=3890
the first is pontiac v8, the second is chev and the arm won't reach the cam to make it pump

I have the right pump (first one in your email)

when you put the pump in the hole and install the bolts try leaving the bolts a couple of turns loose. the pump should have some spring pressure holding it up, when you push it down several times it should pump fuel without you turning the engine. I do this to prime carburators when installing engines etc. If you don't feel spring pressure when you push down on the pump then the arm is not coming in contact with the excentric.

this is what your eccentric looks like https://www.opgi.com/grand-prix/G240303/

That helps, thanks! - but how can you install the pump incorrectly? It seems the excentric will come around and eventually will have to push down the pump?

There is a tab on the back of the eccentric that can brake and not allow it to work correctly. Mine was broke and I had to have it replaced. I hope that is not the case here.

Thanks guys, now I know what to look for. I will take a peek in the hole to see if that thing in still there, or if its loose. If I need to get in there, I might as well drop in my new Ram Air IV cam..

Did you clear out the fuel line from tank to pump? may be something clogging your line, blow out with compressed air. Replace all the rubber lines as well.

I experienced this same problem and went through same steps to remedy. Eventually, disconnected rubber fuel line between fuel pump and carb filter. Attached a hand vacuum pump ( mine is called a Mityvac ) and drew gas from tank up to attached reservoir.
Reattached fuel line and car started right up. This primes the fuel lines and pump.

Hope this helps,

Jeff

Jeff, I can't get any vacuum build up...you leave the reservoir on the pump with fuel in it? You draw vacuum from the fuel pump fitting where the steel line goes to the carb or the larger hose that routes to the tank?

The Mityvac or similiar has hoses & fitting, plus a small plastic bottle, several ounces,(reservoir) with it . One outlet of the lid for bottle should be marked to pump and the other outlet goes to source. This is used to draw brake fluid, gas, etc. and to isolate from pump. I used a cone shaped fitting on the end of plastic hose the apprpriate size to fit snugly in gas line. It is easier to attach this fitting into rubber gas line on top of engine between fuel pump and carb. You are trying to draw fuel from gas tank through your fuel line and fuel pump up to that point. You may not be able to draw through fuel pump though. Next step would be to disconnect rubber line between hard steel line running from rear to front of car. Right where it attaches to inlet fitting of fuel pump. Try to draw gas into plastic bottle again, you will not see much vacuum with bottle attached. Keep squeezing pump until gas enters bottle. When you see an ounce or so of gas, STOP. Respect the gas. Be ready to disconnect vacuum pump from fuel line and reconnect line to fuel pump. As stated in another post you can clamp rubber line full of fuel with vise grips. If you can not draw fuel with vacuum pump , this is why fuel pump is not working. Since you said you blew out steel line, you can rule that out. Next easiest thing to check would be rubber fuel line between fuel tank and steel line in the rear. If hose is split or not clamped correctly, pump will not draw fuel. Steel line to front has a ridge around it and rubber line should extend over it and be clamped behind it. Sometimes rubber lines can seem to be installed right when they are not. Especially when they are in hard to reach spots.

On a car that was previously running, this would show up as a gas leak. But, on a fresh restoration this is just a vacuum leak, preventing fuel pump from drawing gas. Last resort without dropping gas tank, is to attach hand vacuum pump to rubber gas line right outside of gas tank and see if you can draw fuel from tank.

Once again I hope this helps and I am not leading you down the wrong path !
I know it is painful to get that far and not have your Bird running.
I wish I was nearby to help in person

Jeff

>but how can you install the pump incorrectly?<

By installing it with the pump’s arm over the top of the eccentric, not under the it.



>This primes the fuel lines and pump.<

Likewise with dumping a half shot glass of gas down the primaries, and firing the engine. Sometimes you have to do it twice.

Update: First of all a big THANK YOU to all of you trying to resolve this issue. I finally figured out what the root cause was. To all of you guys that clean of replace gas tanks: YOU NEED A MINIMUM OF 8 GALLONS OF FUEL IN THE TANK FOR FUEL TO FLOW!!!! It took me a couple of weeks of trial and error to find out 5 gal was not enough! Wow what a waste of time! But she cranked up just fine so far, now on to changing oil again and putting mix in the radiator, fixing a few nicks in the paint and she'll be on the road again after a 15 year rest (hopefully gettn' the 'ol lady to quit her bitchin' about taking up the 2 car garage