Bad gas mileage/backfiring problem

[Eclispetuner95]

So I have a 95 eclispe gs-t with a 6 bolt swap with the following mods:

rnr 3in exhaust, no cat (test pipe), 16g turbo, k&n air filter,boost guage. Boost is set to 10psi.

I get horriable gas mileage, around 10 MPG, we rebuild the head about 2 months ago due to a broken belt and that actually fixed the gas mileage once we put it back on the road. But that only lasted a couple of days when it went back to 10. My car always backfires and causes a loud pop whenever i shift inbetween gears. You can smell gas out of the exhaust which means I am running rich, and we have come to a conclusion that it is an electrical problem but I was wondering why the ecu would tell me car to throw in more fuel? I look at the boost guage and whenever im at idle it goes down past zero to about 10mmHG when it should be at 20 i believe. I checked other forums and we have checked the injectors, o2 sensor, plugs, etc. but have not done a boost leak test. Could a leak contribute to that much loss in gas?

 

[DSM_PWR]

Yes a boost leak can definetly lead to bad gas mileage, simply because the ECU is seeing more air, which is going to dump in more fuel.

Id recommend doing a boost leak test along with checking all the vacuum lines.

Are you throwing any CELS?

 

[Drubble]

I didn't see anything in your profile, but it sounds like you need to something to tune with as well to lean out your a/f ratio since you are running so rich.

 

[DSM4me44]

I myself have a 6 bolt swap and have the 14b turbo with 16g hotside. I am running 21 at idle no 10

I'd say you should log it or use link to see whats going on.

Also, if it was something like an o2 sensor, you would throw a light or your air/fuel gauge would stop working completely (if you have one).

 

[Eclispetuner95]

Yes, I do have the CEL on but I bought the car from another owner who had a shop do the 6 bolt swap and the CEL light has been on ever since.

 

[Eclispetuner95]

Also my step dad pointed out that my wastegate does not move and its internally gates on the 16g which could mean I am boosting constantly. It almost sounds true because when I press only a quarter of the way down i am boosting 5psi between 2-3 grand and boost is set to 10psi. If my wastegate is messed up, maybe that could be a problem.