Stuck guide pin

[DValentine]

I had the injector pump rebuilt 30k ago. Pulled the fuel cone to see if the pin was moving, as a routine kind of inspection. The pin will only come out about 3/32 of an inch. I squirted in my favorite lubricant and worked the pin to no avail. It moves easily... . only 3/32 of an inch. Before the pump rebuild, I had checked it and it worked well... . slide out to the other side of the bore.



What moves the pin under normal operation... . fuel pressure? I also had diesel in the fuel cone bore. So I guess the seal is bad also.



Dave

 

[dpuckett]

Yup, you got a leaking seal. Sounds like it may have swelled, or got a nick or something. And since you have "tampered" with it, be prepared to say goodbye to the warranty.



Daniel

 

[DValentine]

Seems to be the logical thing Daniel. I am not worried about warranty issues. The Bosch guy is reasonable. I just figured that someone here would have an idea why the pin wouldn't move. My guess is that you are right... . the seal has been nicked.

 

[Greenleaf]

The pins will move very easily when the O rings are worn and will not always leak. Then, when the new O ring is installed it's tight, and the pin will not slide easily however the adjusting lever/tensioning lever along with the governor sliding sleve will exert enough force against the reverse lever to actuate the pin and overcome the grip of a new (tight) O ring.



There is a method used to "test" the operation of the AFC by the use of grease placed onto the control cone profile and operating the vehicle. Then the cone is removed again to observe the witness mark in the grease on the cone profile, made by the fuel pin.



GL

 

[DValentine]

Thanks for the reply Scott. I gather from what you said that the lever is moving the pin under load... . not when sitting in the driveway... . with me looking down the bore with the old flashlight reving the engine. I presume that the pin is sliding... as power has not dropped off in any noticable manner. I will look for witness marks, using grease.



Thanks,

DV

 

[dpuckett]

Not to stir the pot, or be argumantative, but when I had my opld o-ring in there, it was VERY tight. Put the new one in, and the pin slid easily. Took it to the shop to get flowed, said it was leaking "profusely. " Now guide pin is sticky again, but I still get a hair under 30psi, so I imagine it is moving. Old Blue wouldnt even make 30psi without the AFC functioning.



Daniel

 

[Greenleaf]

guide pin is sticky againl

. . and there you have it... ... Nice and Sticky Oo.