Backstory: Almost two years ago I purchased a brand new Accufab FPR directly from one of the popular vendors (along with the purchase and installation of numerous other items while assembling my recently rebuilt stroker). The first few times I ran the car, I noticed a rather peculiar hissing-type noise coming from the regulator but it eventually went away. Also, the fuel pressure would drop to zero PSI within 30 seconds of shutting down the car. I attributed these symptoms to having just installed a virtually all new powertrain in the car. I attributed the fuel leakdown to a possible check valve in the fuel pump. No big deal.
Fast forward to today. Up until now, I have had an erratic idle, unstable BLMs, IAC counts all over the place, stumbling, and--on occassion--stalling. However, the car always performed tip-top at anything off idle, to include WOT. Recently, what really got my attention and had me start taking a fresh look at all of this was I noticed my rail mounted fuel pressure gauge needle started vibrating, like so fast that it was blurry. Threw a different gauge on there...no change. I had also installed recently installed a new fuel pump a few weeks back so I was pretty confident that the fuel leakdown was not the pump.
Here's what I found after disassembling the Accufab: a small sliver of metal was wedged at the bottom flange of where that silver ferrule sits in the bottom half of the assembly. Note the wear on the inside walls of the cylinder that the ferrule rides in. This is the piece that the check valve rides on top of when the regulator is fully assembled. This scrap pieceof metal looks like it was left over from the machining process and the damned thing was assembled without any quality control measures. It was not from a damaged part within the regulator itself, as the ferrule, spring, check valve, and diaphragm were all in perfect condition.
I cleaned it all up, reassembled, and reinstalled. I had to work the adjustment screw up and down throughout its full range of travel a few times to get a stable reading but now I have perfect fuel pressure, no fuel leakdown, a rock-steady idle and IACs/BLMs stay put.
Bottom line is that I think Accufab's products are garbage. I have one of their 70mm throttle bodies and am not impressed whatsoever (although that's another story). Maybe there's another turbo Buick owner out there with these same symptoms and perhaps it will help.
Fast forward to today. Up until now, I have had an erratic idle, unstable BLMs, IAC counts all over the place, stumbling, and--on occassion--stalling. However, the car always performed tip-top at anything off idle, to include WOT. Recently, what really got my attention and had me start taking a fresh look at all of this was I noticed my rail mounted fuel pressure gauge needle started vibrating, like so fast that it was blurry. Threw a different gauge on there...no change. I had also installed recently installed a new fuel pump a few weeks back so I was pretty confident that the fuel leakdown was not the pump.
Here's what I found after disassembling the Accufab: a small sliver of metal was wedged at the bottom flange of where that silver ferrule sits in the bottom half of the assembly. Note the wear on the inside walls of the cylinder that the ferrule rides in. This is the piece that the check valve rides on top of when the regulator is fully assembled. This scrap pieceof metal looks like it was left over from the machining process and the damned thing was assembled without any quality control measures. It was not from a damaged part within the regulator itself, as the ferrule, spring, check valve, and diaphragm were all in perfect condition.
I cleaned it all up, reassembled, and reinstalled. I had to work the adjustment screw up and down throughout its full range of travel a few times to get a stable reading but now I have perfect fuel pressure, no fuel leakdown, a rock-steady idle and IACs/BLMs stay put.
Bottom line is that I think Accufab's products are garbage. I have one of their 70mm throttle bodies and am not impressed whatsoever (although that's another story). Maybe there's another turbo Buick owner out there with these same symptoms and perhaps it will help.
