I did a search for my problem and I found the exact problem here in this post

NBLANCHARD's Fuel Problem

My problem is the same as nblanchard's problem... got a Crane AFPR installed and I attached a Hypertech Fuel Pressure Guage to the Shrader Valve... I installed a new pressure regulator (that thingy with the diaphram)...

After I installed it all and adjusted my pressure it was fine, at idle my fuel pressure would sit at around 42 psi solid...that was two days ago... now my pressure guage is jumping all over the place at idle!! I mean the needle is really jumping back and forth between 40 and 50 psi, almost like it's quivering it's jumping that fast....you can almost time it to the injectors firing...

Not sure if nblanchard found his problem or not because the last post was from Chris (IROCKER)...

Anyway...figured I would throw it out there...

PS: It seems to me that my car is running rich..... she idles fine and drives fine but if I'm standing beside her while she's idling I get a nice smell of gas on my clothes (can't remember her doing that before!)

 

To my knowledge, Nathan has not been able to figure this gremlin out. My stays steady so I can't offer an explanation. You did remove the little valve mechanism/thingy from the schrader port before installing the gauge right?

 

Nope, I never... there was nothing in the instructions with my Hypertech fuel guage that said for me to remove anything inside the Shrader Valve... The weird thing is this... back in January I installed my freshened up injectors, Crane AFPR, and screwed my fuel guage onto my Shrader Valve....... I fired up the car and adjusted my fuel pressure with my guage (approx. 44 psi)... the needle held steady.... everything was fine and I left my car alone...

Then in March I went back to my car and did a few small things, the pressure guage was working fine.... before I was ready to leave I disconnected my battery and in the process of doing that I accidently dropped my vise grips across my battery terminals... at the time I never thought anything about it...

Last Saturday I went back to get my car...never paid any attention to the fuel pressure guage as I was a little anxious to get her out on the road.. As I was driving home I noticed my CD Receiver was not working... never thought much about it....

Yesterday evening I sat in my car and I also noticed that my dome lights weren't working... after closer inspection I noticed a few other electrical things were not working...

Upon closer inspection I found a 20 AMP fuse blown... this fuse was off by itself in it's own separate holder...I replaced the fuse and sure enough all of my "non-working" electrical devices were now working...

It was only then that as I had the engine running I noticed my guage bouncing all over the place....

After looking in the Chilton electrical section I see that the Fuel Pump Relay is connected indirectly to what they have labelled as "Fuel Pump AutoFuse 20 AMP" ... coincident maybe???

I can take this fuse that blown out altogether and the car will still start, idle fine, run fine...

Do ya think I fudged something in the Fuel Pump Relay???

If I put my hand on the rubber fuel line going to the meter I can feel the erratic surges.. almost like a pulse timed to the engine...

 

I had a similar issue a couple of years ago when I installed my TPIS AFR.

I had already bought new relays for the MAF and Fuel pump.

When setting the fuel press I saw that it was a little erratic.

I thought nothing of it but after the change out of the relays the pressure did not bounce around so much.

I also noticed that my fuel pump had a better sound to it at startup (not sure if the connections inside relay were degrading).

tj

 

The problem was not with the fuel pump, it was not with the Fuel Pump Relay, it wasn't with the Fuel Regulator, or the AFPR...

The problem was with one lousy 20 AMP fuse....the fuse which I never knew existed....it's called the Fuel Pump AutoFuse - 20 AMP. It is located in it's own separate holder, clipped to the fender right by the battery.

I called a friend of a friend who is a mechanic at a :hail: GM Dealership (don't know why never thought of him before). Told him my problem, he pointed me to the fuse and sure enough it was blown... when I fired the car I looked at the fuel pressure guage and it was once again solid!!!

My new found mechanic buddy :hail: :hail: said that when I dropped my vise grips across the battery terminals I must have almost blown that 20 AMP fuse, weakened it to the point where it was causing the Fuel Pump Relay to not work properly because of improper current through the fuse. When I went and put power directly across the fuse in a "tap .. tap" fashion by jumping the two wires in the plug it finished it off....

Popped in a new 20 AMP fuse and I am set once again!!!

Another good thing came from all this is that I noticed that someone did a **** poor job on the wires going into the Fuel Pump Relay plug...looks like a hack job... I have this on my "to-do" list to fix up properly before I put my car back on the road!

Thanks to all that replied!!!

Ya learn something about a 3rd Gen everyday!!! LOL

 

Glad to hear you're getting forward progress Stan. I hope your able to get the car out soon.