Pontiac Owners Club UK

Hi there.
I've got a 64 Star Chief with 389 motor which i'm havin probs gettin petrol to.
Petrol comes out the tank when i pull pipe off and the front to back pipe is clear.
I've had the pump apart and all seems ok - main diaphrams not perished and valve diaphrams seem ok too... but its not pumping! >:(
any ideas???

fuel pump push rod broken? or push rod actuator lobe worn down so much that its not pushing the push rod so to speak?

remove the pump and check the push rod. I checked mine whilst i had the pump off a few weeks ago by pressing it into its channel, and got my dad to turn the engine over with a spanner at the crank pulley. I verified that the rod moved up and down a decent distance.

not sure if it push rod or lobe but engine done 61000 - would that be enough to wear the lobe?
if it is a worn lobe, how easy/difficult to replace - will i be able to find a replacement?
thanx ian

If the lobe is worn its a new cam shaft. 61000 is low but it depends how the engine has been maintained. It needs checking to verify it before you go down the replacement route.

did you try operating the pump manualy while it was off?

SUPERCHARGEDGTA wrote:did you try operating the pump manualy while it was off?

Yeah, main diaphram went up n down nicely an very little wear on the actuating arm. So popped it back on but narfink!!!
....hope it not a worn lobe - sounds like a big job
I can feel an electric fuel pump comin to the party....

did it suck/blow if you put your finger over the pipes?

I'm currently investigating electric pumps and have drawn up an electrical circuit including safety cut out so give us a shout if you find out that you need it.

I would take the pump off again and test it as John has suggested - see if it sucks/blows.

I notice you say the fuel runs out the tank if you take the pipe off and the pipe is clear - does fuel run out if you disconnect the pipe at the pump inlet then? I'm assuming it does.

Yeah, think i'll recheck the pump off the car - fuel did come out the pipe when i removed the pump and i also blew on air line down it just in case.
Your electrical circuit sounds interesting ian - keep me posted?
What electric fuel pump would you advise to use?

I just thought, if i split the pump on the car i should be able to see if the diaphram is moving.... if it is then maybe it the one of the valves thats at fault, can these be replaced as i knocked one out unintentionally or more the point are they still available?????

I'm not sure if I'm going to need an electric pump yet so I've not looked into which one.

The mechanical pumps are fairly easy to get hold of but not sure about the individual parts inside.