ok, so i bought a 88 civic with a b18a1 motor in it. its been running rich since day one and has also been showing code 43. ive replaced air filter, o2 sensor, spark plugs, fuel filter. and it runs a little better but still rich and showing code. i've recently found out from the previous owner(who also doesnt know much about cars) that he had a mugen chip in the ecu. could this be the thing that is causing the car to run rich? also i only get about 225 miles on a full tank of gas. i've done a lot of googling and probably read about 10 threads on this subject but dunno which direction to take. any help would be appreciated. thanks!

 

get a proper ecu for it, a stock obd0 pr4 is what you need.

 

is it possible to just remove the mugen chip? and my car doest run right unless the dizzy is advanced all the way, is the chip also causing this?

 

Those ecus are cheap, I would change it out. See them on cl all the time 40-50 bucks.

 

Code 43 is only thrown by OBD1 ECUs, and is exclusive to the Civic/Del Sol/Accord/Prelude platforms, Integra ECU throwing code 43 even being OBD1 would theoretically be impossible.

you sure its not code #4 and code #3?
#3= Map sensor
#4=ckp

To me,it sounds like it is a possiblilty of it being the ecu.does it rev up slowly and run like Sh$t?
Id also try making sure your tps is adjusted correctly,and remove and clean the iacv.also,unplug 02 sensor and see if code(s) go away.

 

I had a b18a running the 91 si ecu ran fine no codes, switched to a 91 integra ecu and
got code 43 obd0 ecu. Changed the o2 and the code went away.

 

Someone wrote 90-91 mugen chip pr4 on it with a sharpie so im guessing its a integra ecu. Ill google up on how to clean iacv and on how to adjust tps. I ordered a stock obd0 pr4 off ebay(pray for me...) so hopefully thats the problem. And it does rev up slowly and run like shiet if i have the dizzy set on tdc so i put it back advanced all the way like when i first got it. I heard thats bad for the motor though so im hoping to get access to a timing gun soon. ive changed o2 alredy with same results.

 

Also the code is 4 long flashes and three quick ones so pretty sure its code 43. Could be wrong tho

 

ok so got a stock obd0 pr4 and its running a little better still showing code 43. maybe the"mugen" chip messed up the new o2? or maybe fuel injectors?

 

Fuel pressure regulator, or vacume lines.

 

got new fuel pressurr regulator. checked vaccumm lines..running a little leaner. STILL have code 43. bout to give up. maybe fuel injectors or bad wiring? will spark plugs and/or spark plug wires cause code 43?

 

May have oversized injectors.

Find some good oem ones.

 

check all 4 injectors if there clicking
get a long screw driver or a long rachet extension put it in the injectot the other on your ears.

should be getting continous clicking

 

does anyone know what happens if you dont use a resistor box or it isnt working or hooked up right?

 

the injectors are from a b20. will check later to see if tgeyre clicking or not

 

also dont have a control box or fpr cutoff solenoid
dont know if thats causing it or not.

 

if you have b20 injectors....are you using a resistor box or not?

 

yes i have a resistor box. is there a cel code specifically for the o2 sensor because when i unplug it nothing happens.

 

there code 1, 2, and 41

 

so what explains no code popping up when the o2 sensor is unplugged?

 

ok checked injectors..all read 2.1 ohms. so its peak and hold.

 

what ecu are you running?
obd0 or obd1?
does your car have resistor box?

 

running obd0 with resistor box. starting to think its the rewiring job.

 

have you checked if injectors are clicking or not.

 

yes all are clicking