vw caddy diesel non starter

[squawwoods]

hi,my son has a caddy diesel[1995]which after starting and warming up for 5 minutes cut out and failed to restart,he called out the AA who checked that there was fuel and that the cambelt was ok he advised that there is a problem with the fuel pump!is there anything else that i can check before we go down this expensive route?are there any common problems?

[carbon]

Fuel cut off solenoids can fail, it’s not an everyday occurrence but it does happen.
Check that powers getting to it, if it is remove the solenoid, plunger and connect it to the battery. If the plunger doesn’t move then the solenoid’s faulty. An other way to check it is to remove the solenoid, remove the plunger then replace the solenoid. Then try to start it, if it then starts it shouldn’t be a problem with the injection pump. The problem with this approach means you now have to stall the engine to get it to stop as you’ve bypassed the stop control.

[squawwoods]

hi chris thanks for that,i should of explained that i have tried what you are suggesting,it seems to me that the shut off solenoid works on a repel basis as opposed to opening ,ie there is a spring loaded valve/shuttle which is closed when no voltage is present, and once voltage is activated shuttle/valve is repelled closing fuel return port?

[carbon]

I’ve not worked on a caddy for some time but most of these valves work on the same principle.

When the coil is not energized the valve is released and the spring closes the valve ports in the pump stopping the engine “A” in the linked diagram.

When the coil is energised the valve is lifted opening the valve ports in the pump allowing the engine to run “B” in the linked diagram.


Fuel cut off solenoid