Racetronix 255 pump tuning issues

It’sjusta6

New Member
Specs:
87 grand national
Racetronix 255LPH fuel sender
Billet FPR by Racetronix
Completely stock in every way besides that

Thank you guys first for any knowledge or any info you may have!

Pump and regulator was installed on the car for preventative maintenance on an old fuel pump. Plugs were also changed from .45 to .35… since then I cannot get drive ability to be like it used to be. Adjusted the regulator per factory instructions and even took pictures of the old pressure on key on, running with and without the reference line on the stock regulator. Then matched those number with the adjustable regulator. Idle feels great and you can stab the throttle while in park and it sounds great. Under load is a different story. Lots of pops and burbles under load, and hardly any power. Have played with the fuel pressure running all the way from 35-50 even just out of curiosity and while it seems to feel best at 45-46, it still is not anywhere close to where it should be. My question is what could I be doing wrong to finalize drive ability. Can I use the stock 233 regulator on this style pump and would that fix my issues? I don’t understand how I can go over such a broad range of fuel pressure and no matter the range I can’t get it back to where the stock pump was. Thank you guys very much for the help or things to try! I don’t have a scan master sadly so I am reaching out to you before I buy one.
 
I don’t have a scan master sadly so I am reaching out to you before I buy one.
Get one and post the data before we can make some accurate suggestions.
What chip is in the ecm?
A detailed list of other info such as mileage, prior work that may have been done, etc
 
Like Chuck mentioned get a Scanmaster.

I'd suggest not driving the car at all until you get one installed.

Are you able to monitor fuel pressure at all when driving? If not there are some relatively inexpensive units that tap into the fuel rail and you can tape the gauge to the windshield for testing temporally. Knowing what the fuel pressure is doing while driving and under load is very important.

You mentioned that you had changed spark plugs. What plugs were in the car before and what plugs did you replace them with? An engine breaking up under load can also be ignition related and being you also were working on ignition components I wouldn't totally blame fuel pressure until your able to test it.
 
Hot wire for new pump? New fuel filter? Plugs gapped correctly? Plug Wires ohmed or better replaced? Check that coil with a meter but a know good swap to see might be better. Upgraded maf with translator?
Lots of things but these were the first few I came up with.
Are you doing the work or at least have a known good place that is doing it? These cars are a mystery to most.
 
If the chip is stock , get one from Turbo Tweak . The stock chip is not good for todays gas and Eric's chips provide way better drivability . Also get a hotwire set up to take the strain of high current off the 36 year old fuel pump relay and old wiring .
 
It just so frustrating when you try to just do a few simple good things to a perfectly good running car and now its broke.
All the good advice has been said and asked. Im just saying read and reread the first 5 post and take baby steps.
Yes the OE stock regulator will work.
The fuel filter should have caught the crap you broke loose changing the pump.
I hope you changed all the fuel lines at the tank, and none are kinked.
Just a reminder Turbo Buicks are temperamental if you're doing the work yourself. And you should be.
If its Eddies Auto Works, that works on your Dads 2016 GMC, He's in way over his head, and dose not know it yet.
 
If the chip is stock , get one from Turbo Tweak . The stock chip is not good for todays gas and Eric's chips provide way better drivability . Also get a hotwire set up to take the strain of high current off the 36 year old fuel pump relay and old wiring .
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