Help? Anyone?

[Nix]

First let me say if I ticked anyone off with one of my rants, I'm sorry for doing so. Sometimes I get a little hot under the collar about diesel prices and will readily admit that I have gone overboard in several posts, and humbly apologize.

I have a reoccurring FPR failure. The first one went at 70K, and the replacement was deemed bad at 114K. I would like to know what the contamination looks like that determines whether or not the pressure pump should be replaced, as I plan on observing every step of the repair procedure. My truck,like many here is my livelihood,and I take very good care of it. I would really appreciate any advice from one of the many experts(as well as anyone else that has gone through this)so that I can make sure that it gets fixed right this time.

The dealership quoted $850 for the repair. I was also wondering if this is in the ballpark for this repair. They also told me that the pressure pump was warranted to 120K, which I was also wondering.

I was under the impression that the fuel injection system will not function properly without the FPR, yet GM's stance is that it is part of the fuel system so it is not covered past 100K.

Please help!

[Jim Brzozowski]

No, it won't function right without the FPR.
Suggest you add secondary fuel filtration to keep contaminants out of the system.

[More Power]

The FPR (Fuel Pressure Regulator) is a part of the Bosch high pressure fuel injection pump. The computer monitors fuel-rail pressure, and commands the the FPR to deliver what it wants for any given engine speed and load. If there is more than a 20Mpa difference between commanded and actual pressure, it'll set a code.

Back in 2001, there were a number of owners who's FPR failed for one reason or another, which was causing an engine rpm variation while idling in either Park or Neutral. GM indicates an engine rpm variation of up to 100 rpm as within tolerance. This level of variation is just barely detectable by watching the tach, but can fairly easily be heard/felt.

In the early days, GM issued an updated ECM calibration to help correct this problem or, in stubborn cases, authorized dealers to replace the entire Bosch pump (which includes the FPR) for this problem. GM has since allowed dealer technicians to replace just the FPR.

Clogged fuel filter(s) or fuel supply, or excessive vacuum in the fuel tank (due to a defective cap) can contribute to this problem.

Jim

[Nix]

Thanks for your help. I change my fuel filter every 5K, buy BP diesel from a busy truck stop, and put FPPF Fuel Power in every tank. How can I tell if cap for the fuel tank is defective?

MP, are you saying that GM will no longer authorize replacement of the pump if the FPR is bad, even if it shows contamination? Also do you know whether or not the pump is warranted to 120K like the dealer told me, or are they blowing smoke up my you know what? How do I verify this? In my experience with this so far the independent sources(non-GM related)have always been more reliable. If it is true I have less than 6K left on the warranty, and really want to make sure that it gets fixed properly, because I have to sell one of my favorite(rare!) bass guitars to fix the FPR. I'm sure that if the pressure pump goes bad that it will cost me a heck of a lot more than the FPR.

Also, if anyone out there knows of a stand-up shop in the Northern IL(McHenry County)area that does GM warranty work I would greatly appreciate the info.

After I get this fixed the JK Mega Filter kit is my next purchase.

Thanks to all for your help.

[More Power]

FPR's are usually replaced because they aren't doing a good job of fuel pressure regulation (too high/too low - variable). The injection pump would be replaced if it isn't able to generate the required fuel-rail pressure (always low).

So, someone will need to diagnose what the situation is with your pump/FPR, so as to make a recommendation whether to replace just the FPR or the pump, or both. From a consumer standpoint ($), you only want to replace the part that is at fault.

I haven't heard of a 120K warranty..... As far as I know factory coverage of the Bosch pump (and FPR) expires at 5/100. There might be some emissions aspect that might alter the warranty length, but I'm not aware of one. Check the emissions warranty documentation in your owner's manual.

Jim

[Nix]

Jim,

Thank you so much your help, I truly do appreciate your input.