Fuel Pump troubles

[DamianJP]

Working on a XR4 '89 fuel pump and when I dissassemabled it, for the Diaphragms it had two Solid ones.

---Why do I have a hole through the fuel pump base? Seems like the Diaphragm(Solid) against it blocks it.

---Also on the Chamber plate, it had a Diaphragm(Solid) against it aswell. Seems like it's blocking the front brass piece.


Seems like the intructions that came with the fuel pump have this order.

Pump base , Diaphragm(solid) , Gasket , Fuel pump body , Gasket , Diaphragm , Chamber Plate


Seloc Had this order.
Pump base , Gasket , Diaphragm , Pump body , Diaphragm , Gasket , Chamber plate

Which is the right order???

Pictures here http://s281.photobucket.com/albums/kk233/damianjp_photos/Fuel pump schematics/

Plus I didn't have the Diaphragm with Oil mixing holes. What is that one used for? Is that a problem on a oil injected motor?

Could someone shed some light on the subject. Don't wanna block up the oil from getting to engine or something to go wrong.



Thanks,
Damian

 

[j_martin]

Re: Fuel Pump troubles

Working on a XR4 '89 fuel pump and when I dissassemabled it, for the Diaphragms it had two Solid ones.

---Why do I have a hole through the fuel pump base? Seems like the Diaphragm(Solid) against it blocks it.

---Also on the Chamber plate, it had a Diaphragm(Solid) against it aswell. Seems like it's blocking the front brass piece.


Seems like the intructions that came with the fuel pump have this order.

Pump base , Diaphragm(solid) , Gasket , Fuel pump body , Gasket , Diaphragm , Chamber Plate


Seloc Had this order.
Pump base , Gasket , Diaphragm , Pump body , Diaphragm , Gasket , Chamber plate

Which is the right order???

Pictures here http://s281.photobucket.com/albums/kk233/damianjp_photos/Fuel pump schematics/

Plus I didn't have the Diaphragm with Oil mixing holes. What is that one used for? Is that a problem on a oil injected motor?

Could someone shed some light on the subject. Don't wanna block up the oil from getting to engine or something to go wrong.



Thanks,
Damian

The XR4 mixes the oil in the fuel before it gets to the fuel pump. Use the 2 solid diaphrams.

Usually, if the problem is low pressure, it's one of the disk valves that's bad.
The pulse is supplied by a rubber hose to the crankcase. If that line is soft, it can lower the performance of the fuel pump. (been there, done that)


The kit is for multiple pumps. Some parts are not used.

hope it helps
John

 

[DamianJP]

Re: Fuel Pump troubles

Thanks John,
Had me stumped for a sec.Do you know what order should I install them.

Seems like the insructions that came with the fuel pump have this order:

Pump base , Diaphragm(solid) , Gasket , Fuel pump body , Gasket , Diaphragm(solid) , Chamber Plate


And Seloc has this order:

Pump base , Gasket , Diaphragm(solid) , Pump body , Diaphragm(solid) , Gasket , Chamber plate

Which is the right order???

Pictures here http://s281.photobucket.com/albums/k... schematics/

BTW: Pump check valves had nylon plastic dics holding rubber ones. Edges of old rubber were being stressed and sucked into sides. Did away with rubber, just used the *new* pastic discs.

Thanks,
Damian