Has anyone changed a fuel solenoid on a DS4?

[GM Guy]

Hey all,

Has anyone successfully changed a fuel solenoid on a DS4? Got a buddy that has a bad one, ohmed out bad. Pump ran awesome prior.

 

[MrMarty51]

I changed out the leaking solenoid on My 2000 K3500, unplugged the wiring connector, used an open end wrench and twisted it right out of the hole, twisted a new one back in and it fires up and shuts down just fine.
I hope there was not some precautions I missed in so doing.

 

[schiker]

The fuel metering solenoid has to be set to the proper depth so it strokes correctly. I think the window is pretty small.
The "cone/needle" and seat of the closure mechanism has to seal and the solenoid has to be at the complete stroke or it would burn out trying to continue to draw higher current would be my thought. The solenoid fires so fast I think it would hammer the cone/seat if set was too long and either burn out the solenoid or fry the FSD.

I assume they use some feel a guage type method to get the stroke correct. But not sure how they determine it? I don't know if they measure the play in the rotor axial movement to cone & seat distance and set the plunger gap at the back of the solenoid or if it is a set spec.

The fuel shut off solenoid is a dumbish type. Its normally closed by spring and opens to the stroke of the solenoid and not critical. You can just swap those out and screw them in til they bottom out and seal.

 

[ak diesel driver]

Need a clarification on which selenoid we're talking about.

 

[GM Guy]

sorry, yes, the metering solenoid. Not shutoff.

The burning up due to incorrect depth might explain his current situation, lol.

I assume anyone that is eating PMDs could be caused by a improper depth FSO?

 

[schiker]

A solenoid generally will burn itself to a short if it can't travel to the point the induction flux is balanced reducing current thru the coil just like inrush current of an electric motor if it can't reach synchronous speed soon enough. Sometimes motors are limited to certain starts per hour for this reason.

The metering solenoid fires in the millisecond range so I think it has a digital signal too. There are 2 contacts that get touched by a "T" on back on the plunger. It wouldn't surprise me if there is some logic that knows the plunger is at full travel and knows it can reduce the current in conjunction with the induction flux equalization.

Generally, a shorted coil will not pull in and draws high current due to short and will blow a fuse supplying the coil.

If it works and runs for a while with new FSD but burns new FSD out seems to point to plunger not traveling far enough since the FSD has to supply inrush current for higher duty cycle time. So I assume with the FSD's reputation it can't handle this higher inrush current duty cycle and is the weakest link. It would also make sense eventually a new solenoid would short out too.