i have a 92 civic with a d16 the idle surges when you first crank it until it warms up i replaced the tps,iacv,only because the ecu was giving that code.after replacing those the ecu gives a new code one long flash then 4 short which in the chilton says crank angle positioning sensor.any ideas thank you

 

i would probably replace all the vacuum hoses - cost 2 to 3 dollars. i did that.
did not replace the 2 big ones - off of the brake booster or off the iacv (or eacv).
should be able to look at them at tell if they are bad - those small hoses though, you cannot do that - at least i could not.