I baught a DX motor. (i think it came from a 89 hatch)
I think they put the multi port injection from my HF on the DX motor and i think im useing the same HF ecu from the old motor.........My questin is.... why do i get 18MPG

That really sucks ass...... it really bugs me cause im a Pizza delivery guy and i got to fill up like every day almost



..........Any Help please
.......Thanx

 

i have a dx ecu if you think thats the problem.

 

did it come from dual port injection motor??
and what car did it come from.

 

As long as it's a 4th gen DX ECU it is dual port.

 

should he use an si ecu, cause im not sure if an HF would be able to give it enough gas, had the opposite setup on a friends car, hf motor with si ecu and it wouldnt go over 65 cause it would get too much gas, but what ecu are you using now?

 

Im useing my HF ecu but i get 18mpg ...... it really sucks
what should i do????

 

that sucks, even my car gets better gas mileage than that. pull out your plugs. at 18mpg on an hf they should black. maybe your odometer is fucked up.

 

does it smoke? if it does what color? your rings might be bad... what tranny do you have on it? the dx or the hf? part of the HF's amazing 35+ mpg is those amazingly long gears

all i can really say is do what b16 said to, check your plugs, if they look fine then i dont know what to tell you, is your check engine light on or anything?


also, you say you THINK its mpfi? im not sure if an hf ecu would run with a dpfi manifold but pop ur hood, and look to the back of the engine on top, is your intake manifold like a kinda black circle with PGM-FI writtin on top? or is it a metal manifold and 4 runners coming from underneath to the engine?

 

Yes its a multi port injection manifold on a DX motor........... and yes he is runing a HF ecu

 

Whats up ?????18mpg