Turbolude

Just installed a bosch pump inline and installed a fuel pressure regulator/guage. What are the stock settings? When i have it set at 30 psi my a/f guage shows it being lean and i can hear my exuast backfiring/puttering. If i go to 40 psi i have a black smoke coming out of my exuast(that means running rich right?). What pressure should i use?

G

Is there that much of a difference in 10psi? Wow.... Well, were you driving the car when it was backfiring and running lean? On the 5th gen, idle puel pressure is @ 30-37psi with vaccuum and 40-47psi without. I am now at 40psi with vaccuum, 5-10psi more than stock is good for the off boost to boost transition........ Have you tried 35psi?

Turbolude

is there a difference in pressure with the 4th gens having bigger injectors? Ive tried everything from 25-50 and cant get nothing to work...my spark plugs are completely black. I cleaned them and ran 30 psi and my a/f guage was pegged all the way red and i could here sputtering, when i got back they were completely black again.

G

What else have you done besides the pump and regulator? It may be another problem besides fuel pressures (you could have the pressure, but no flow). When you say pegged at red, that is the lean side, right? Keep your pressure at 35-40 psi. Check all the sensors. Are you using the bosch with the stock in tank? Is your bosch mounted below the fuel level in the tank (if the stock has been removed)? Have you changed anything else? Are you pulling your hair out yet? Do you hear that bad boy whining, knowing that its on? Remove your stock pump (if you haven't done so already).......

Turbolude

yes i am about to kill myself! The stock pump is out, im using the bosch pump mounted inline below the tank.

G

Did you check 15 times to be sure the pick-up line is where it should be and that there are no leaks on the stock pump replacement modification? If there is air getting into the feed line... you know what I mean....

Turbolude

Havent really checked for leaks inside the tank. Wouldnt filling the tank all the way to the top fix that? Also, isnt there spot in the tank specificaly for the pickup? Anyhow, i still cant figure out why my a/f guage is saying lean when my spark plugs are completely black. So when are you coming over to VA again. I need you to fix this problem and make a 3 step for me and do some other misc mods.

G

I'll do the 3 step here. On my way to NYC, I'll drop by and give you a hand. When you did the stock fuel pump mod, did you measure the distance from the top plate to the inlet of the sock thing? I am just thinking that if air gets into the fuel line, it would cause rich and lean conditions. Since the pump is so strong, the pressures wouldn't change so much yet air may be present in the line. Rich when there is fuel and lean when there's an air pocket. Did you change anything else? What are the other mods, maybe I'll do them to my car.....