Fuel Pressure Issues

[84BuickGNYorkPA]

Here is a old picture of the stock fuel lines, one of the 1st things to put on when assembling the accessories up front. Kirban's and Highwaystars both sell the stock set of lines. On my return line at the frame (the old line that is on your car now) I had to drill out the inside diameter (make the through hole bigger) so I could turn the fuel pressure lower. I had a cheap set of drills which worked good, I opened it up as much as I could, when the crimp was made at the connector the restriction was substantial enough that I couldn't get enough flow to lower the pressure at the regulator.

 

[Wknight13]

So they do weave through and behind the alternator, air, etc. I will need to remove all that you have shown in the picure? Red being the supply and Blue being the Return. Did you run new lines then? Just curious as to the reaming out th e line, was the factory pressure not what your setup called for? I'm not sure what the previous owner was doing with the large lines but I'm sure that is why my pressure is only 30psi. I'm going back to stock to get my pressure back. Supply is 3/8 and Return is? What if they were reversed? Too much pressure? Is it the 3/8 that is engineered for the 40-45 psi? I know the I.D. of the line is what matters. **** I need to actually talk to someone who knows these fuel pressures on these cars instead of these forums. Who can I call that may be the authority of the fuel delivery system?

 

[84BuickGNYorkPA]

Well they are against the block basically, the red is the supply and the blue is the return, I was in the process of putting new timing chain, cam and heads on in this picture. You can't get the lines wrong, they are different sizes, it's not hard to get the motor to this point, just takes a little time and patience, after you do it once it's very simple. A lot of my friends are in the 10's with stock lines, about 2 yrs ago there was some trouble with the walbro pumps, but that has been corrected, maybe the PO was trying a different direction, looks to me that you found out why he sold the car... I wouldn't hesitate to go back to stock lines.
These two lines attach at the driver's side frame rail, if you go back to the stock lines, you will have to do your best to clean them out.

Chuck

 

[Wknight13]

Thanks Chuck.....Oh I plan on it for sure. Just getting the preliminary knowledge and obtaining parts. The PO ran a new supply (1/2" I believe) and used the old supply as the return, with an SX external sump. Not knowing how much he cut away, I'm trying to prepare. I've been tossing around the idea of obtaining the proper I.D. of braided line and just connecting to the transitions points of the original lines. Anyone know the thread sizes of these? I haven't torn out the current setup to be able to find out, car still runs great, just a bitch to ignite.

By the way, whats the deal with the Walbro's from a couple years ago? The one I have coming in has 3000 miles but works fine. The guy said he was having pressure issues and automatically went to a new pump, but it wasn't the problem.

 

[84BuickGNYorkPA]

I would never buy a used fuel pump, in fact some replace them every year for cheap motor insurance, depends how much you run the car. Dropping the fuel tank isn't hard to do but again a pain in the *ss, so why you have it apart, I would put new parts in.

Chuck