fuel pump not sucking?

[Ophitoxaemia]

i put a hose from the inlet to the pump into a can of gas, then cranked the car.. no gas went into the tube. is this proof my pump needs a rebuild? or do i need to prime it? (i opened it up and put some gas in there).

the car has been sitting for many years and all the gass has turned to brown gunk.

(i replaced the rubber fuel lines and sprayed gumout into everywhere i could)

-james

[zoom240]

They make a little humming noise & pumping sound when working. If it's ok electrically, you might get lucky & just clean it out. There's a metal mesh filter in the pump intake that will get clogged up. Barring that you might have to replace it... you can even cheat & use a low pressure over-the-counter GM replacement and save some money.

[Ophitoxaemia]

um, isnt the block mounted pump mechanical? i thought there were two. i attached a hose to the one in the engine compartment and am feeding it from there.

sorry, new to z's!

-james

[biker]

There must be confusion about the type of pump you have got. Lots of people have gone over to electrical.

I have a mechanical pump on the block which runs off the camshaft lobe. Inside of this is a diaphram. A quick check is to disconnet the inlet hose to the pump and tunr over the motor. You should be able to feel some strong suction. If not there are chances that the diaphram could be rats.

[beandip]

If the mechanical pump is faulty there is a vary good possability that if the diaphram is bad that fuel is running into the crankcase! Now that being said and something to look out for. If you need to replace the electric pump and have an access to a bone yard , find a Masda RX-7 that is NOT fuel injected. You should be able to get one for about $15.00 and they work just as good and the Datsun unit. Just be sure it is for a carberated car. This will be a low pressure pump.

[Ophitoxaemia]

well, it doesnt even suck any gas into the pump, so i think its so gone its not sucking gas into the crankcase.

the little flap was gunked up, so i suspect it cant suck air well at all. i am planning to take it all the car, take it apart and clean it.

the rubber seal on the top part was in perfect, like new condition curiously enough.

-james

[beandip]

If the mech. pump is bad and you add a new electric unit you may vary well be pumping fuel into the crankcase! If the diaphram in the engine mounted unit is faulty fuel will pass through the hole. You can eliminate the engine mounted pump altogether and just run the electric. This is what I am doing.

[Ophitoxaemia]

i cant seem to surf up a page describing what i need to do to convert to all electric. i think my 73 has both an electric and a mechanical.

can you point me to the right place?

thanks!

-james

[kmack]

If your car is a '73 model and you do have the electric pump mounted just in front of the gas tank, then you don't have much left to do to convert to all electric.

First, make sure your electric pump is clean and working. The bottom section of the pump (at the very bottom while looking at it on the car) looks like a cap of sorts. Twist this cap off and pull the mesh screen filter out and make sure it's all clean. Then make sure the pump itself is working. It should hum slightly when working. If it's working, you're another step closer. Next pull the mechanical pump off the block. You'll need to either buy (from VB or MSA, etc.) a block-off plate or make your own and mount it in place of the mechanical pump. Attach all your fuel lines and your done!

Start the car and enjoy the ride.

[JEFF]

I just went through this very thing yesterday!!!

Take the fuel line off at the fuel rail- turn the ignition to run ( do not crank ). put your thumb over the hose - there should be air pressure.( yes AIR pressure if the pump is working ) if this is the case then take the fuel line off the tank and be sure it is not cloged. If it is not cloged then stick it in a can of gas. The pump

does not need to be primed. If your pump pumps gas out of the disconnected hose then the problem is in the tank pick-up hose, as mine was. thankfully I do not need that tank!!

Hope I helped.

- Jeff

[JEFF]

You can also feed cleaner backwards though the hose that is connected to the inlet side of the fuel filter with a oiling can or the like.

- Jeff

[Mr Camouflage]

My fuel pump want working one day, so i unbolted it from the engine, cranked it by hand a while, and whaddyaknow, it started working again. nover had a problem with it again. Maybe i was just lucky. the car had been standing a while also.