I have a 90 civic hatch with a b16a2. The car is running rich, i put new plugs about a week ago and they are black now. The inner part of the exhaust is real black. Sometimes when i come to a stop it will sputter just a little. Any ideas?

 

Several things could be wrong.

First off, check your MAS air flow sensor.
Check your oxygen sensor.
Check the injectors.
Check any connections around the injectors (see if any wires are worn down or disconnected).
See if your ECU is screwing up.

That's a basic diagnosis. Someone may suggest something else, but that's all I can think of right now. Now if you think everything is fine, then you may need to check your harness and go down it to see if it's putting out the correct ohms to the injectors. Also find out this about the injectors you have right now: are they high or low impedance? Make sure there the correct impedance injectors. That's something most people won't ever think of checking.

Personally, from what you are saying about it sputtering and being black... your spark could be off. Did you gap your plugs? If you didn't, I would definitely do so. It's small things like that that can make a difference.

 

B16s have a MAP sensor, not a MAF. Also check the throttle position sensor, and the coolant temp sensor.

 

I don't know much about B16s, sorry.

That is true, throttle position sensor is definitely one to check out.

 

Hondas also run rich naturally. Is your ecu chipped? Mine does the same after I had the ecu chipped with a more aggressive fuel map.

 

I have a stock ecu, im thinking its my fuel pressure regulater

 

Probably not.

 

Never hurts to change it though. It'll just cost money though. I think brand new regulators from the factory can run like at least $150.

Then again, I could be wrong since I'm used to Mazda ripping me off for parts... and there being no relation between them and Honda.

 

Blindly replacing stuff is an expensive way to find a problem. Get some help, or grab a factory manual, and start going through and checking the usual suspects. Find out what works, and then you'll know what doesn't.

 

ok here's an idea. Someone correct me if I'm being retarded since I just woke up, but b16a2 is obd1 right? If you have a 90 ef make sure your resistor box isn't hooked up.