There has to be be different overflow values for the '94 to 96 P7100 pumps.When I ordered my overflow value from Piers,I told them the year of truck...Well I installed the new value and my idle pressure went from 37PSI(old value) at idle to 25PSI(New value).At 2500RPM the pressure is 32PSI now.There has to be to different P/N for the '94-96 and one for the '97-98..Is this true???

 

I was told that there was a up-dated one know for all years but I thought the pressure went up? Thats my 2 cents.

 

The FP specs are the same for all 12 valves.
Your old valve was screwed up, the new one is reading right.

 

Thanks...The Hayes manual was then wrong.They made it sound like two different pressure values...Thats why the change on my truck...Check my post about the injector pump on the way out...

 

So is your truck running fine now?

 

I will know today.I had to do a quick linkage adjustment last night.If I get to the next town thats about 60 miles away,without a shutdown...Then....I hope the problem is fixed...

 

I did the old trick that I read about from the forums and some of the older posts.I stretched the spring to around one half inch Now i have 30-40psi all the time even at idle and WOT. If its cool like say around 40 degrees it will be at 40psi at say around 60 degrees it will stay around 30 psi this is with the stock lift pump.

 

All of the overflow valves are the same for the 12 valve motors 94-98, Bosch part number is 2 417 413 101

 

Im going to try a different route with mine. I bought an adjustable fuel pressure regulator off of ebay. Havent got my truck back up and running yet but im anxious to see how it works out. I think it should work pretty good.

 

Be careful with the adjustable fuel pressure regulator. Many are designed to regulate the pressure before it gets to the pump, excess pressure is held back and doesn't flow though the injection pump to help cool it. These type regulate the downstream pressure. You want one that sustains the upsteam pressure by releasing the excess to the return line.