vwtechnician

So I have installed a stock LS1/T56 out of an 02 firebird into an old Volvo 240 station wagon. I'm getting rich faults and bucking when trying to give more than 50% throttle or go higher than 4200 rpm. Checking the fuel pressure this evening and at idle it completely pegged an 100psi gauge. The setup is as follows

Low pressure in tank pump feeds external Bosch 044. 044 feeds stock ls1 fuel rail, returnless, with a -6 line.

Now my question is this. Can the stock, in rail regulator (I think they call it a fuel flow damper?) simply not handle the output of the 044 or do I have a one off failed regulator? Trying to determine if I just need a new regulator or if I need to change the setup to have a return regulator or maybe an inline regulator before the rail. Thanks in advance for any help, just got this running last Tuesday and it ran like a beast for about 6 days before this cropped up. Pics for clicks

LsF-150

iTrader: (2)

Im a little confused, you state "returnless" but using 02 firebird rails which are return style. I assume thats a mistype and you are actually running a return style system. I would start by pulling the return line off the rail and see if you can blow through it towards the tank, sounds like it may be restricted. The stock regulator and rails should handle an 044 just fine. If the return isn't restricted it's probably something with regulator, I wonder if you have a piece of trash in there since you just got it running and it was fine for 6 days.

vwtechnician

Got it figured out. It is a returnless rail but what looks like a regulator is a fuel flow damper and has nothing to do with regulating pressure, the regulator was built into the sending unit. I have to replace the stock Volvo fuel filter with something that has a built in regulator a la the corvette filter. Modern VWs use one like that with a 4 bar rating. I'm going to add one of those in (since I can get it at work, cheap) along with a return line from it back to the currently capped return port in the sending unit. Feel a little stupid, something didn't seem right to me that the "regulator" in the rail would be able to drop the pressure from the pump without a return. Should've done more research instead of listening to people. Thanks for the reply.