Sxynerd

I just changed my 96npi to a 99pi/w and I used the 96 wiring harness and tune. But i dont understand why i would only get 180 miles out of a tank of gas? Granted i've had my foot in it since sunday on the first 2 tanks (btw 180 miles each and filled up 14ga each time.), but I have only gone 46 miles on the third tank and im already down a full 1/4 from the full line.... ??????? I dont have any leaks. Can someone explain?

thanks

Mike

droptoppony

Try getting a dyno tune...its not required to make the car operate after the swap but if you want it to run its best you should get the tune. Your air/fuel ratio may be off...with the new higher level off airflow the computer may be dumping too much fuel in causing the poor mpg.

travisl1213

thats what i get in my 98

badboystangGT

same here even with the ported heads and no cats

JPGT_00

I would go get it tuned, prob running a lil rich.

Sxynerd

BELIEVE me i was ready to loose some gas milage Just not that much! I could get 330 miles to a tank with a tune and my NPI motor! That probobly half the reason I had et's of 16's and high 15's! lol My car is just making up for all those good cheap miles! All at once! LOL I'll call my tunner this week, money willing!


thanks,
Mike

Dan04COBRA

The car being untuned is your answer. Kind of a no-brainer, boss!

That's a big huckin' got you got in your sig! LOL

lizzyfan

I may sound repetitious, but a dyno tune will fix ya up!!!!

handyandy

I have the exact same thing happening to me. I'm down to 3/4's after like 20-30 miles. Where do I get a tune? A shop, or a tuner like an sct xcal or diablo? How much would it cost to get a shop to tune it up to fix mine too? Do they dyno it to do this?

dsg04gt

Thats my standard miles per tank... completely full. I'm usually right at 3/4 tank marker when ive gone 50 miles.. 95-105 at half a tank. And i fill up at 170ish, i could prolly get more out of it.