1990 Honda Civic 1.5L

I have a 1990 Honda Civic with a multiport fuel injection system and an ECU from a 1990 Acura Integra 1.8L and gets only about 16-20 mpg because it runs extremely rich. Does anyone know of some sort of chip that will limit fuel?

You have the wrong computer in the vehicle. You need to have the right programing for the engine in your car. So put the original computer back in.

Why do people do this?

Tester

Kind of sounds like one of those go-fast things gone wrong.

OP, don’t assume because the mileage is lousy and it’s running rich the problem is too much fuel. Too much retard on the timing, which is controlled by that ECU you added, can do the same thing. Along with a leaking fuel pressure regulator, and a clogged converter, and…

Dude . . . like, lose the Acura 'puter  Fuel rail and go back to factory.  You're making life hard on yourself.  A salvage yard can help with this year Hondog.  Rocketman

alright i’ll consider finding another ECU for it, but just for the record the fuel injection and ecu was put in by the previous owner so its not a matter of “oh i’ll just pop the old stuff back in.”

Was it running OK for awhile and then started having problems, or was it guzzling gas from the first day you got it? Does the check engine light come on?

If the ECU (Engine Control Unit) is working, it should be compensating for the differences in the engines. You need to check the same sensors (and actuators) that you would check if it had the original ECU. The oxygen sensor may not be working, or may be disconnected. The engine coolant temperature sensor may be faulty (or, disconnected). The MAF (Mass Air Flow) sensor may be faulty, etc.

It was guzzling gas from the first day i got it. the check engine light comes on every once in a while, had everything checked out (including sensors, timing, EVERYTHING) and everything is fine. runs rich. All of these responses don’t answer my question though. Is there a chip?

wrong ECU and it isn’t designed for the correct displacement, valve timing, exhaust back pressure, and many other things. My 1990 Acura Integra 1.8 got great mileage and was driven by two teenagers until sold at 160000miles, and they drove the heck out of it and got 27mpg. Find the right ECU and it will pay for itself…junk yard part.

So what if the previous owner put in the ECU and fuel injectors? Why can’t you “just put the old stuff back in”? From salvage, the ECU may cost $50, and the fuel injectors $10 each.
So, unless the previous owner did a lot of butchering, you CAN return to the days of yore.