help! cant pass emissions test cause im running wayyyy too rich,

JDM B16A with K&N filter...
spark plugs are BLACK
AFR = 13.12 : 1 @ 800rpm
AFR = 12.81 : 1 @ 2500rpm

how do i work out why it is so rich? or is it something to do with the O2 sensors being not hot? how long does it usually take for the computer to go into the right mode?

thanks for any help with this problem,

t..

 

would too high a fuel pressure lead to rich conditions? (i have an aftermarket fuel pump...)

what are the specs for the 1st gen B16A O2 sensors?

would dirty fuel injectors also create a rich condition?

what about the PCV system?

thanks,

t..




[Modified by tinkerbell, 11:27 AM 1/21/2002]

 

Do you have a fuel pressure regulator?

 

If the system is in closed loop mode, reducing the fuel pressure will be compensated by the computer increasing your injector pulse width.

This can be tested by inducing a small vacuum leak (which should cause the motor to run lean) and seeing if the computer compensates for it.

Some manufacturers only go into closed loop under load. If in open loop lowering fuel pressure should cause leaner running.


170 hp + 1850 lbs =

 

yes i have a fuel pressure regulator, my car is fuel injected.

i am using an aftermarkert high pressure pump of the Bosch variety (maybe a bit too high i guess...)
should i get an adjustable FPR?
which brand? what should FP be set to?

will this for sure lean it out?

if it is in closed loop mode doesnt this mean it should be tuning itself? how do i tell if it is doing this?

when will the computer go into closed loop mode? at all times unless CEL?

thanks heaps for your thoughts,

t..



[Modified by tinkerbell, 8:43 AM 1/22/2002]

 

what other mods do you have that you need a fuel pump? unless you have really high compression and huge cams, or FI....the stock pump is fine. Do you know how much pressure is in the fuel lines? I think stock 44psi.

 

no mods,

except a B16A in an '83 Prelude means i went from carburetters to EFI, which meant going from a 4psi pump to a 40+psi pump plus surge tank etc.

anyways, would an increased fuel pressure lead to running rich or not?

how do i lean it out?

last night i checked the cam timing and i hadnt missed a tooth,

i also tried to measure teh voltage of the O2 sensors but im not sure what to look for, at idle the V was ranging from 0.1 to 0.3v but this isnt what my emissions test showed...

how do i test the O2 sensors?

how do i lower the fuel pressure if this is the problem?

thanks,

t..