Topic: fuel pump

[stevehecker]

i dont realy know what to feel for i just put the pump back on and still dont get any gas i also blew air into the fuel hose and vapor retun line and nothing is blocking it air went in to the tank. the pump is new but it is smaller than the old one. I ordered the one for the 350 and it is the same pump i see online for the 350 but the old one i had on their was bigger

[stevehecker]

i compared them side by side and the pump arms are identicle. dont know if the old one is for the 400 or some other engine but its bigger

[78w72]

short of having a bad new pump....there has to be something  wrong with the eccentric.  it may be there physically but, the hole could be chewed up or the bolt is lose,  therefore causing it to not be offset & not able to move the pump arm.  (you mentioned it had alot of side to side movement,  it should not have any)

so....unless there is something clogging the line(s) or the pump is bad, it kind of has to be the eccentric.  test the pump as mentioned above & see if it pumps fuel, or you can just put your finger over the intake hole & pump the arm to see if there is suction.  if there is, it is most likely a good pump.

a fail proof eccentric test is to feel if it's "offset" with your finger, or something else you can stick in there.   due too the mentioned "risk" of damage to your finger try this....  have someone turn the engine over by hand with a socket on the front dampner bolt. (remove the plugs to make it turn easier)  that way you can safely  feel if the eccentric is operating properly.  it should move in a sort of out of round circular motion. if it doesn't that is the problem.   but if you are carefull as i said, you can just have someone lightly bump the key so you can feel it move.  unfortunantly that is the only way to verify the eccentric is good.... 

i hope that's not it but like i said, i just had a car that had the problem & my friend's t/a just did it a week ago.   test the pump/eccentric & keep us posted.   

[ta6point6]

I have had to use a hand pump to pull fuel to the pump. It is a long way for the fuel pump to suck gas all the way from the tank. I just bought a 2.00 dollar Walmart hand pump. Also make sure when installing the pump that there is some tension when tightening down the screws, that way you know the arm is pushing against the eccentric.

[stevehecker]

thanks alot that is all good advise I will try it tonight, I was working on my other firebird it wasnt running either but i finaly got that one figured out and on the road again. its been a long week and a head ache with two birds down on the same day.

[stevehecker]

come to the conclusion that the eccentric is shot. i stuck a ratchet wrench in their to see if it would move the wrench back and forth while my wife crank the engine over but it didnt move the wrench. i felt no pressure at all. so i am wondering if it would be better to put an elctric pump on or have mechanic fix the eccentric.

[stevehecker]

just ordered the electric fuel pump i will be able to pick it up tomorrow morning at 9:30 I cant wait to get this bird running again. I love advanced auto parts.

[jphillips3333]

Yep - sounds shot.  Will the electric be a pusher or a puller?

[ta78w72]

You did the opposite of what I would have done.  I would have pulled that timing chain cover.  That way you could see the chain.  It may need to be changed anyway. 

You put a ratchet in there?  I'm still not convinced that your eccentric is shot.  I guess if the little tab broke off it would slip.  But then I'd want to find the tab in the bottom of the pan.

[stevehecker]

maybe the eccentric is fine but i cant seem to get the pump arm to catch it

[ta78w72]

With the pump on, did you try pouring gas down the carb to see if it would start? 

I wouldn't go through all the hassle of an electric pump until I knew for sure what the problem was.  And, even then, once I figured out the problem I'd fix it and put the mechanical pump on.  But that's just me.  Lots of people like those electric pumps.

How many miles does the engine have on it and has the timing chain ever been replaced?

[jphillips3333]

What Russ says is true - you still want to know why it doesn't work from a mechanical perspective EVEN if you want to put the electric on.  BTW, most people opt for a pusher - have the electric near the tank.

Logic dictates that you remove the cover and see what's going on.  How old is the water pump?  What about belts and hoses?  I mean, you're there and that stuff is peanuts.

If you end up replacing the chain, consider a double roller or better still, a gear drive if you like the whine.  I used to have a wife that liked to whine but that's another story.

[ta78w72]

I've been through this with my daughters Trans Am.  The little doughnut gasket between the intake and timing chain cover was leaking....a 20 cent part.

I pulled the radiator....it had a leak...bought a new one.  Decided to replace the water pump while I was at it...and of course new sleeves and back plate.  Saw the loose timing chain so I replaced that.  I bet I spent close to $500 for that stupid little leaky gasket.  But now I know her car is OK.  Runs a heck of a lot better too. 

[fireman_033]

  You say you can feel back and forth play and the eccentric spins free?  Do yourself a favor and pull that timing cover before you do more damage.  Scott

[stevehecker]

well i didnt actualy buy the electric pump yet i just ordered it over the phone and they said i could pay for it when i pick it up