Should i go to a larger fp? Or just need a tune?

281pony

Active Member
Aug 31, 2003
2,681
2
46
Oly, WA
i have the mods in my sig with 24# injectors and a 190 lph pump. im wondering if i should upgrade to a 255?

im going to be replacing a fuel level sending unit, so i figure now is a good time. i ask for a few reasons. first, the car seems "faster" with less throttle, like im starving for fuel. next its easiest to install it now. someday i may get it dyno-tuned and i dont want to run into any restrictions with my 190 pump.

there is no plans to upgrade power, i am probably not keeping the car much longer either. i just want it running well obviously. my fp is at a stock 38 with the car idling. not sure what that would equate to with vacuum off.

thanks for the input. ive gone through searches and looked at similar combo's but seems to be a toss up. :shrug:
 
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The 190lph should be enough pump for that combo, I would rather see a 30# though...

If it is going lean under WOT then it could mean the inj is too small, you can bump the pressure up to help with that issue. Bumping the pressure up only adds the additonal fuel at WOT, when the car is using the 02's down low it will adjust the pulse width to make the A/F correct.
 
thanks rick, i was hoping someone like you would chime in.

i actually re-read my post intially and removed the part about injectors. buying 30's isint an option for me really. i dont have the money, plus i am back and forth on keeping this car once i get a job. so for now, im just trying to make sure everything is working well.

what would you suggest i try for fp? from 38 now, to say 45?
 
Bump it up in .5-1lb increments and keep reading the plugs to see how it is running at WOT.

You will need to make WOT runs, shut the car off then read the plugs to get an accurate reading without a wideban on the car.
 
ok, if i can run it with this fuel setup, that saves me 100 bucks for the pump.

there is a dyno shop pretty locally that charges 50/hr for a wideband tune. i may just go there and get it tuned better. i havent played with my timing or anything since the car first ran so im pretty sure there is a good amount of power to be gained.

i dont go wot hardly at all. i also dont really have anywhere i can hammer it to test. im in a residential area, and then the city is right off this. so unless its clear getting onto the 35 mph road, i never do anything.

that would be a better idea then running the streets around here i think anyways :D thanks for the input rick.
 
well i upped the fp a little bit. all i can say is JESUS CHRIST it liked it. :nice:

feels like three times the power in the first-second gear that it was lacking in before. ill definately plan to get it dyno tuned soon.