Logo
FULL SITE MENU

'93 25HP J25RETS, Fuel pump replacement

25Johnny

25Johnny

Contributing Member
Gents,
Got a Sierra replacement and the center vacuum hole is blocked. Original uses 2-outboard holes as mounting holes and a hole in the middle is open to engine vacuum. However, both pumps has a 3-hose going to to another source for engine vacuum. Wondering if I have a newer version of fuel pump that eliminates the vacuum source behind the pump and relies on vacuum from the hose? Thanks!
 
Facts for you.---It is a + PRESSURE pulse that drives the pump.------If both pumps have 3 barbs is that hole on the back open or is it blocked ?-----They may use the same part with holes open or blocked for different models of motors.----Those pumps are very reliable / easy to install repair kits on them.------I would never buy a new pump !----What is your motor doing / not doing that leads you to spend this money for a pump ??
 
Last edited:
If the pump has three hose fittings, the third one is the pulse hose and the hole on the back is not used. But the hole on the back is blocked, either by a blind hole or by virtue of a gasket when mounted on the motor.
 
fdrgator said:
If the pump has three hose fittings, the third one is the pulse hose and the hole on the back is not used. But the hole on the back is blocked, either by a blind hole or by virtue of a gasket when mounted on the motor.
Click to expand...
This is what I have. The hole in the middle is plugged, meaning not drilled out.

Thanks for the explanation racer, I thought all the fuel pumps used crankcase vacuum.
 
Back
Top