VWDiesel.net The IDI, TDI, and mTDI source.

Engine Specific Info and Questions => IDI Engine => Topic started by: derekp on October 26, 2010, 01:34:31 pm

Title: help - what is this solenoid for on my pump (not the shutoff either!)
Post by: derekp on October 26, 2010, 01:34:31 pm

I pulled this pump outof a junkyard, forgot to check what year the car was, but it was an NA diesel.
Put it on my 92 eco diesel - now if only I can figure out if my wastegate is adjustable so I can bump it up a little

Can someone tell me what the solenoid is for (red arrow points to it in pic)
It bolts to the timing pin cover thats on the front side lower part of the pump.
I guess it has something to do with timing - I'd like to know what its for and  how to make use of it

Thanks!

(http://i1210.photobucket.com/albums/cc401/derekp19426/InjSolenoid.jpg)

Title: Re: help - what is this solenoid for on my pump (not the shutoff either!)
Post by: snakemaster on October 26, 2010, 01:39:32 pm

cold start ,it addvances the pump on start up

Title: Re: help - what is this solenoid for on my pump (not the shutoff either!)
Post by: derekp on October 26, 2010, 02:50:04 pm

if I try to use this - should it get voltage while cranking ?
Or should it get voltage til warm up (based somehow off of temp sensor?)
Or should I just not bother?
thanks!

Title: Re: help - what is this solenoid for on my pump (not the shutoff either!)
Post by: Vincent Waldon on October 26, 2010, 03:04:02 pm

Actually, at least in North America, the cold start mechanism is usually on the back, and the solenoid in this picture on the front is usually part of the pump's emission control system... when energized it deactivates a slight timing advance under specific engine operating conditions.

As such, it can safely be safely disconnected with little or no noticeable impact.  Some folks report their engine runs slightly better with it connected to +12... YMMV.  

There are quite a few threads on the board discussing this sucker.... mostly as a curiosity, since even the Bosch Yellow Jacket books only refer to it in general terms.... of course I can't find a really good one at the moment... but if I do I'll post back.

BTW... I say "usually" twice in the first sentence because there are many different Bosch VE pump configurations worldwide.  If you can find a lever and cable on the opposite side of the pump that pretty much has to be the cold start mechanism, making the front solenoid the one I describe above. 

Title: Re: help - what is this solenoid for on my pump (not the shutoff either!)
Post by: derekp on October 26, 2010, 03:08:57 pm

Hi vince.
I'd like to pass on to you that your instructions on how to set pump timing are a great help.
I've referred to them often.
Your other tips are quite useful too!

Title: Re: help - what is this solenoid for on my pump (not the shutoff either!)
Post by: Vincent Waldon on October 26, 2010, 03:11:34 pm

Quote from: derekp on October 26, 2010, 03:08:57 pm

Hi vince.
I'd like to pass on to you that your instructions on how to set pump timing are a great help.
I've referred to them often.
Your other tips are quite useful too!

Great to hear... thanks.  I have a little map of the world on the site that shows hits from all over the place... lots of us "diesel heads" out there... many of whom have taught me stuff as well!