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Engine Specific Info and Questions => IDI Engine => Topic started by: rs899 on September 26, 2010, 10:50:21 am

Title: Long vs. Short Delivery Valves
Post by: rs899 on September 26, 2010, 10:50:21 am
I noticed the older IP I rebuilt has shorter delivery valve that the one that came out of my 91 Jetta.  I also noticed that the hard lines are different  :'(

What is the difference in the delivery valves ?

I was going to pull the valve off the '91 pump, but I see that one of the valve is missing a small shim that goes under the spring.  I assume this makes a difference (may be one reason my car wasn't running all that smoothly)
Title: Re: Long vs. Short Delivery Valves
Post by: R.O.R-2.0 on September 26, 2010, 10:54:02 am
delivery valves only hold a little residual pressure in the fuel lines from what ive been explained.. but can affect the running of the engine also.

BYM or Vince would have a better answer for you tho. BYM builds (built) fuel pumps, and vince just knows a little about everything..
Title: Re: Long vs. Short Delivery Valves
Post by: Wayland on September 26, 2010, 11:14:11 am
Do a search on the site. Lots of info. I had this same question a while back, and found out what I needed to know fairly easily.