I know it has a FPCM, so I'd assume so...

 

In my testing this morning I did two WOT runs back to back with little more than 4 gallons in the tank. The low fuel light came on the instrument panel but the fuel pressure never faltered in my scanner. I usually don't and won't make a habit of WOT runs on anything under 1/4 tank, but its good to know my bucket refilling is keeping up even under 1/4 tank.

 

Chavette,
Do you have flex fuel bucket or non flex fuel bucket? My truck is a non flex fuel. Was hoping to install the Walbro in the factory bucket like you did but don't want it to run out of fuel if I'm low or towing a trailer.

p.s. You just cost me a lot of money, ha ha. I noticed you're running an AES390. I was looking at AES blocks when I had my GTO. Now instead of rebuilding my stock (165k mile) bottom end, I think I'm going to AES...

 

Mine was flex. Bucket not running dry had been my concern too.

AES were good people to work with.

 

Okay, if the flex fuel and non flex fuel buckets are different, maybe I'll pick up a used one.

How long ago did you deal with AES? After doing a little reading, I'm worried by some recent reports...

 

Engine, I picked up in early 2012.

I picked up a junkyard bucket to think and tinker on ahead of pulling the tank. You can always put your unmolested stocker back in if something goes south with your plan.

Added note: A harbor freight plastic barrel pump and two 5 gallon cans will make short work of emptying the tank after the pump is out.

 

Okay posting up my results of disconnecting the in-tank regulator. Lower boost and the only issue I have seen is the fuel pressure has to drop back off as the engine burns it away or it flows out the 1/4 induction valve at bottom of bucket. Higher boost I get a fluctuating pulse in pressure as the FPCM finds the right recipe and then the taper off again. I can't say that it causes any running issue to the engine yet, because I am logging so much stuff in this test tune, the resolution on the WB has to suck and I have not spent any quality time in high boost tuning yet (cause I just got a fuel pump to be able to do that). I can say the pressure spikes were not there with the in-tank regulator hooked up before. So I am either going to hook the in-tank back up or add a boost regulated right outside the tank on the rail where I put the external filter (would be a short return system and not taking it all the way up to the hot engine bay and back, saw it on the Camaro forum a while back).

 

Mulling the thought over to up the pressure on the internal regulator to the 62 psi to 65 psi range. This would let the FPCM manage the cruise and low boost and then the regulator trim off the spikes at higher boost to get rid of that yo-yo action. The stock part number for the 4 bar is A2C53177244. Still looking but not finding a 4.2 - 4.5 bar dimensionally the same that I can just pop back in place of the stock so far. Any leads appreciated. Second option is I have found on another site where someone compressed the top (center indention) a couple of mm and upped the pressure by 4 psi. Bench testing can be done but will be time consuming setting up without buying a new FPR housing, so still much prefer to buy it the right relief pressure to begin with.

 

Have you tried opening the regulator and disassembling it? Maybe there is a spring inside that can be replaced or shimmed?

 

Thanks for the input, I think that is a great idea......but...... not sure the metal will hold up to being picked apart and re-stamped. And then there is still the process of bench testing the before baseline and the after delta. The attached diagram is the general idea of what is inside but without the boost nipple in this case. I also considered adding a screw and tubing with a spring on top to go through a hole on top to add adjustable tension along with the spring already in there. Realistically if I can't find an upgrade replacement, I might also just drop my running pressure to 56 psi, two psi below my stock regulator and accomplish the same thing. At the moment, I am still holding out for a little more safety margin above 40+ psi at 15 lbs. of boost, though I am sure my ID1000's are good for it. I could also raise fuel pressure in tune when in High Flow mode to overpower my regulator by having the FPCM try for 62 psi which might get me a little more margin, if not a code or two as well.