Fuel Pump Installation, or am I a tard?

Hi,

Fuel pump went out on the '55 Pontiac, so I get a 'new' one from NAPA in hopes of having my downtime be as minimal as possible.

Put it on and nothing. No gas getting to the carb. I pull of the hardline going from the pump to the carb and no gas spurting everywhere out of the pump. I had someone try to start while i had a hand/finger on the pump, but I couldn't feel any indication of moving parts. Would I have?

This should be a no-brainer, right? I can't install the fuel pump to where the actuator arm doesn't make contact, right? (yes, the arms were the same size, or real damn close). I put on a fuel filter, new soft lines and clamps... could I have just gotten a bad pump?

Please advise.

 

Gotta prime the pump. Try some starting fluid in the carb to get it going. should run on its own once that suction is created....

 

I have also seen it done with a wet/dry shop vac.... pull the line off the carb, and suction the line until you see fuel come out... No way am I recommending this, but it did work....

 

When I was done the car actually started... probably gas still in the carb, but it only ran about 7 seconds, if that. I should keep at it then?

 

This is pretty much right. But I bought a bad one from NAPA for my '53 chevy too.

 

Perhaps the eccentric that bolts to the front of the cam is flat or broken. If that isn't pushing the arm on the fuel pump, you're not pumping gas. You might be able to look at it with a flashlight and mirror.... hopefully you just got a bad pump....

 

Yeah I'd spray the shit out of it with starting fluid. Just make sure you're outside of your garage and have a fire extinguisher ready!

 

ok, so I've dumped gas in the carb and started the car maybe 15 times, each time the car running 4 to 7 seconds (or maybe a little longer).

Still not primed?

 

I forgot to mention that I have yet to see any evidence of gas in the fuel filter...

 

with all your dumping of gas down the carb , if that pump was going to work it would have done so by now . somethings wrong.....bad fuel pump , missing eccentric to push on the pump , plugged fuel line , or out of gas in the tank

 

over 1/2 tank of gas... and the fuel line wasn't clogged 3 days ago.

sonofabitch?

 

Is there a little tube in the middle of the carb by the butterfly? Carefully pour some gas in there. That oughtta do it. Went through the same kind of thing with my '53 chevy after the bad brand new fuel pump.

 

I wouldn't do that. Saw a dummy down the street do that and burnt his garage down. Spark from the electrical motor in the shop vac made a real nice explosion. Not safe......

 

i'm curious , you said you bought a 'new' fuel pump from Napa. i can not find a listing for a fuel pump for a 1955 Pontiac at Napa. what is the part number?

 

4566.

 

Well, how would I ensure that I have the follower properly under the cam? I mean, the fuel pump seems to only go on/in one way?

 

If the arm on the pump is a long one, you could have it on the wrong side of the cam. Remove the pump and guide the arm into the hole, canting it in a direction where the flat on the arm will be on that side of the cam lobe.

 

this may be nothing , i am not a Pontiac expert , i may be all wrong...but that Napa pump # M4566 crosses to Airtex #4512. the applications for that does not included a 1955 Pontiac , mostly 347 , 370 and 389 from 1957 and up. if would work for your application i would think they would list it. Napa doesn't list a fuel pump for yours either.

i guess what i'm saying is are you sure you have the correct fuel pump? what does the Pontiac experts out there say?

 

Not sure about the part number stuff, but some of it may stem from the fact that vacuum wipers run off the fuel pump on these cars. I ditched the vacuum wiper fuel pump when I rebuilt my '57 347. Went to the parts store and they had an AC Delco pump, with out vacuum wipers, on the shelf, so I assume the single stage pump is fairly common. I suppose it could be different for '55.... I do still have my old dual stage pump in a box in the garage, I think you can buy rebuild kits for them. You could just switch to an electric pump if its really driving you nuts....

 

One more thing to check is your fuel line. There may be trash in the line, did fuel dribble out of it when you were changing the pump? If not that would explain what happened to the original pump and it might be fine. Try blowing some air thru the gas line and listen for bubbling in the tank.

 

Take the pump off and operate it by hand, see if it sucks and blows as it should. If it doesn't, its defective. A word of warning, don't tell the store guy you did this! They sometimes get all anal and claim you wrecked it by overextending the mechanism and destroyed the diaphragm, or some such nonsense. If it works by hand, make sure you are getting the arm on the right side of the cam eccentric. If that's OK, you may have the wrong pump.

 

this may sound stupid ,but is the tank line going to the inlet port?

 

Thanks for the replies guys!

I know that there is a lot of parts interchangeability between the mid-to-late 50's Pontiac motors so I think that the fuel pump should be ok. However, I am not certain on that. The guys at NAPA said their computer didn't go back to '55, and they had to dig an old parts book out of the attic.

The car did run and drive on Sunday, although it was spewing a LOT of fuel out from the fuel pump. The 'old man' of the parts store said the diaphragm inside the fuel pump probably ruptured and and was leaking out though a little bleed/peephole deal. So, that leads me to believe that there isn't any crap in the fuel line to clog it.

I also verified with the guy at the store which port was the intake port. He verified my assumption, but I'll throw it out here anyways. I have the threaded port attached to the hard line running to the carb while a soft line is slipped over (and clamped down) the other port which is essentially a nipple tube deal.

I'm going to try to get them to ship another pump to the store so I can swap 'em when it gets here. I tried seating/installing that pump 3 times yesterday.... I don't know how much more effort I can put into trying to make sure it's sitting against the cam correctly? Of course, the shop manual is practically zero help in this instance.


Thanks again!

 

took the pump off at lunch and couldn't feel any evidence of suction. I even stuck on a piece of fuel line and tried to use it to siphon some gas out of a gas can I had around. For the record, I also couldn't see or hear any bubbles in the gas can just in case I was using the wrong ports, but I suppose if it was broken/bad I wouldn't anyways?

 

Me and a buddy had a problem like this once,no matter how many times we poured fuel into the carb it would not prime.we took an air nozzle and made a fitting that would allow a brake line stub to be attachedabout 6"long,then poked it through a tennis ball and set it against the tank fill,cracked the line at the carb and very slowly put pressure into the tank just enough to force fuel to the carb.locked the line down and the car fires up instantly!word of caution though,make sure you are grounded because compressed air can create static electricity!also dont blow it full pressure or fuel may come out of the filler neck.we used a portable air tank that was grounded to the floor.

 

If all else fails...I recently had to find a pump rebuild kit for an IH air compressor engine because I couldn't find a pump. There's a guy in Hemmings that sells rebuild kits for old stuff with the correct material in the diaphram and valves to stand up to the alcohol in the gas nowadays. Seems like the price was pretty reasonable, too.

 

Been dealing with the same issue on my '56 Pontiac. Mine would pump from a plastic gas can up front, but not from the tank! Lightly blew air through the filler neck and the tank line isn't clogged...... Both the old and new pump built pressure, but never put much gas though the filter. Starting to suspect it's sucking air somewhere. Still haven't figured it out, but I'm planning on adding a hidden electric "helper" pump.
As for rebuild kits, I see 'em on Ebay all the time. Seem to be around $45.
Hope this helps a little, I'll be watching the thread hoping to get some answers on mine too!
Johnny

 

Not to sidetrack this thread too far, but follow the entire fuel line and look real close for dark colored rust that smells a little gassy. Went thru this recently with an OT stingray and it drove me nuts trying to sort out the fuel delivery problem.....until the pinholed line was discovered buried up in the frame kickup.

 

Knew a guy that usta check blowby by holding a kitchen match over the oil filler hole. He did it on a 6 hole Falcon and blew shit everywhere. I got there in time to see the cleanup of the guy and the un-bulging of the valve cover good enuff to keep the oil corraled. True story....slide