i have a 91 dx 5speed with a rebuilt 93 d15 engine, the car is converted to obd1 and is mpfi. the o2 sensor was chipped out of the ecu but other then that its stock. all i have on it is a CAI, im running on SI stock rims with decent tires. i seem to be only getting like 200 to a tank and its mostly highway driving. i also noticed that in the morning or when i first start the car the idel is at almost 2k, when i drive down the road a little bit it will go back down to about 800 and stay there at idel which is fine. a few other little issues im having is if i just touch the gas pedal a little the engine will rev up to like 4-5k with just a touch of the pedal??? what is the matter with my car? i know i should be getting better fuel millage then this????

 

Unchip the ecu and let it read the O2 sensor.

 

Check your plugs to see if the car is running rich, unless you have a wideband or know someone who does... seeing that your computer is chipped I would imagine whoever did that has one. Also this may seem like a dumb question but how do you drive the car and how many miles are on it. My experience has been when breaking a engine in the fuel consumption is greater then when it's broken in.

 

the o2 sensor is what helps determine how much air/fuel to put into the chamber. Making the o2 not read is probably the issue.

 

well like i said the engine is new it probably has like 5k now the plugs are a little rich but not that bad and everything is new. also its weird cause in 1st and 2nd gear the car has some power but 3-5 almost feel like the same damn gear... ie after 2nd gear the car is sloooooooow. now i know its not a vtec engine or anything like that but its sloooooooow

 

un-chip computer and make sure timing is correct

 

what should i expect for gas mileage? I have an 88 dx with a d16y7 swap with a dsm turbo and an 88 si transmission?

 

oh and its a chipped p28 ecu