Can a fuel pump go bad and still keep the car running? Does it work or just not work?

I suppose the diaphram could be leaking inside a bit and not making as much pressure
You will have to throw a guage on there and check the press. Around 7 psi, I think Somebody correct me if I'm wrong there!

Thanks. The reason I ask is here lately I have to stab the gas to get it to fire up and when I stop it acts as if It wants to die then starts idleing right. Not too long ago I could just turn the key (if warm) and it would fire right up. They're cheap, may put a new one on tomorrow.
I put an elcheapo gauge on it about a week ago and it read 10psi. I think it was wrong,
Thanks again.


[This message has been edited by ss_72man (edited 01-09-2003).]

Sounds more like a carb problem, however, another item to check is the fuel filter. If it's inside the carb inlet, change it often. Choke functioning okay? I would change the fuel filter first and then take a look at proper operation of the choke. I've had MANY fuel pumps fail, always completely, no fuel at all. That's the one item I always carry a spare of! http://www.chevelles.com/forum/wink.gif

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MalibuJerry350
TC Member #1279
Original owner '70 Chevelle.
595,000 miles on car.
Hey, if it's got wheels, DRIVE IT!
My Chevelle: http://hometown.aol.com/erie614/myhomepage/index.html

[This message has been edited by MalibuJerry350 (edited 01-09-2003).]

Yea, choke's fine and the fuel filter is ok.
It's in one of those glass things.
Thanks
PS. Nice Malibu.............Jerry.

[This message has been edited by ss_72man (edited 01-09-2003).]

Those glass ones can be deceptive. Usually filters become clogged due to varnish coating the pores the fuel flows through and you cant tell they are clogged unless you remove them and try to blow through the filter.

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67 BB Prostreet Camaro COMBAT RAT
71 BB Chevelle (SS clone)
80 Camaro Z28 355 SBC
2002 35th anniv. SS Z28

<BLOCKQUOTE>quote:</font><HR>Originally posted by ss_72man:
Yea, choke's fine and the fuel filter is ok.
It's in one of those glass things.
Thanks
PS. Nice Malibu.............Jerry.

[This message has been edited by ss_72man
(edited 01-09-2003).]<HR></BLOCKQUOTE>

Thanks! By the way, what kind of carb are you running? If it's a stock carb, it still may have the internal fuel filter installed.



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MalibuJerry350
TC Member #1279
Original owner '70 Chevelle.
596,000 miles on car.
Hey, if it's got wheels, DRIVE IT!
My Chevelle: http://hometown.aol.com/erie614/myhomepage/index.html

Absolutely! They can still pump fuel, but at reduced pressure and flow rates. That's why I'm always telling people to check their pumps with a pressure gauge for a steady 4 - 7 psi.

I'm back, Hello Randy. Jerry it's an edelbrock 600 1406. Today I bought a vacuum/ fuel pressure tester and got 10 psi+, it pegged the needle. When the car shut off it leaked down slowly. The autozone guy (also a chevelle head)recommed that I replace the fuel pump. I also checked the vac at idle and only got a reading of 12, only around 10 with crankcase ventilator plugged.
Thanks,

Mark

I had the same deal with a bad pump that put out 15psi. I got a new pump that was almost as bad; it was a no-name piece from one of the chains. The Borg-Warner pump put out the correct pressure and my problem was solved. I think they go over-pressure when a valve goes bad internally.

That's true also. The pressure can go sky high from an internal check valve failure. It's rare, but it does happen. I've only seen it happen twice in some 25+ years. But one of those pumps was putting out 20 psi.

[This message has been edited by Randy Mosier (edited 01-11-2003).]

Just put on a new pump and it pegged the needle again. It's holding pressure now though. Got doused with gas when I broke the connetion. Glad I didn't have a cig in my mouth!! Calling autozone back..........
They don't have another in store, will it hurt to run it like this for a day or two?
We have several other auto chains around here, should I keep trying pumps or maybe get a regulator?........................
I just got back from a test drive and it idles fine at a stop and seems like the dead spot is gone. That high fuel pressure thing is still worrying me though.

[This message has been edited by ss_72man (edited 01-11-2003).]

[This message has been edited by ss_72man (edited 01-11-2003).]

Drove around alittle today. Thing is idleing better, running better and generally doin fine. Fuel pressure still over 10 psi.
I called Napa and the guy looked on computer and said he shows it supposed to be in the 7 to 15 psi range. Wierd stuff.
Thanks

Mark

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72ss (clone)
Mark's Website (http://home.triad.rr.com/steelewebsite/chevelle.htm)

"If con is the opposite of pro, is Congress the opposite of progress?"

[This message has been edited by ss_72man (edited 01-12-2003).]

The factory service manual calls for 7 to 8.5 psi pressure. Rumour has it that above the 8.5psi, you may have problems with the needle and seat, especially with the Qjet.

Yea, that's what the info at autozone said.
I might try another pump to see.
The guy there also said that if it was over pressurizing the carb(needle and seat)it wouldn't run without flooding.(?)This is my first time messing with a fuel pump.
Thanks

Mark