Since Its a 93 You can get an adjustable FP reg and crank that baby up. Do as said before and verify that there is no massive Fuel pressure drop when youre driving it hard (tape a gauge to the window.) If the fuel pressure is fine and the adjustable pressure cant help any then I would point to the tuning.

 

yep get yourself an adjustable FPR like he said and you should be alright.

 

I already have tuning (chip) that sets my fuel, so I really think that it must be the fuel pump not delivering the fuel.

 

A 93 is extremely sensitive to fuel pressure, verify the pumps condition then play with your FP, on a 93 adding FP is like adding more fuel in your Program ,it doesnt compensate it out.

 

$1000 to fix WHAT exactly? Holy crap. It shouldn't cost you $500 to replace a fuel pump even if you pay to have it done.

 

hmmm, this should be interesting, because i'm having a somewhat similar problem...with my sig setup, i'm having issues with my top end power...
car hauls azz on the low end, but when on the highway, it doesnt perform as well...needless to say, i'm very confuzzzled.

i guess since my fuel filter was sitting in my car for 8 months before i got the motor ready, it seems reasonable to change it right about now...

riddle me this, folks...if it's the fuel filter, then why doesnt he have issues throughout the entire hp range? why just on the 5k+ regions? perhaps my logic isnt correct, but it makes sense if his car was acting crappy and weak from the get-go...not just when he's hauling azz...

--shokor--

 

Personally, I would would not be bumping up fuel psi until you verify the pump is in fact working WOT. Many pumps will show correct fuel psi idling, but once WOT, they crap on you. This will create a very bad lean condition for the computer will try to compensate the best it can, but it can only do so much with so little.

Good luck.

 

Thats why I asked him to verify the pumps condition , you cannot stress this enough!!...lol But just as canton racer says idle will not tell the story, get a shrader mounted gauge with a long hose ,2 feet will work ,and tape it to your windsheild where you can see it ,go drive around, the pressure should not drop more than 5 PSI anytime and at WOT it should never drop ,ore than a few PSI.

 

Something else, I would keep the dyno time and jumping on it down to minimum with that lean condition

 

The $1000 I was talking about was including opti, water pump, fuel pump, and labor for all that. Just thinking out-loud.

I was unaware of the lean condition until the dyno, and I am being careful now that I know.

Could the pump (if it is going out) be the sole reason for this extreme lean condition?

Thanks again for all the replies.

 

I would think that any deficiency in the fuel system could be the culprit for your lean condition. The few times I have actually run out of gas (like twice) it behaves exactly like a dying pump. It lean pops like crazy.

 

I'm surprised that the dyno operator even let you continue the pull all the way with A/F ratio like that. You can do damage to your car with it running that lean.


Rob

 

He does have problems though the whole rpm range. He is at 16:1 A/F ratio (way way too lean, i.e not enough fuel...) at WOT for nearly the whole run. As far as the choppyness after 5k, I'd worry about that after the A/F ratio was corrected. That could be electrical or who knows. But I wouldn't dyno it again to try to fix that without having the A/F sorted.

 

DON'T WORRY! I have no plans to dyno again with the A/F in it's condition.

I didn't make the pull. Someone else did, and THEN the A/F graph pulled up.

I plan on checking the fuel pressure and most likely replacing the pump. If this is the cause, I hope it will fix my A/F.

Could the 4 degrees of knock (maybe header leak, etc.) cause the jumpiness by pulling timing?

 

replacing an f-body fuel pump spells PAIN IN THE AZZ!!