pgm fi need help.

[87exi]

1987 accord exi 2.0l 5spd.

The weather turned cold and i started to have a problem where when cold idle hunts from 1100 to about 2000 rpm then when warm everything was good,so thinking it was my fast idle valve I blead my collant and toped it off .
I was going to get a new fast idle valve . Then when i was driving with car fully warmed up the pgm fi light came on and the engine started hunting up and down 200-300 rpm at every rpm while driving.Then pgm fi light went off and car was ok ,this happened several times.

I looked at the ecm engine off car on pgm fi light on , the led was on steady no blinks, is this normal?

Then looked at the ecm engine off car on pgm fi light off the led was off,no
led at all, is this normal?

So I am thinking this is 2 different problems 1 idle air valve, and 2 the new one
that trips the pgm fi light.

Some help would be greatly appreciated.

[shepherd79]

if the light is steady, you may have bad ECU.
start the car let it warm up and see if you can triger the light again, except this time don't turn the engine off. look at the ecu and see what it says.

[87exi]

ok it looks like the fault may be engine temp related. when car is cold the pgm fi fault is there ,when warmed up the fault is intermittant.

when engine is running and pgm fi on the led on ecu is on and blinks off with the engine surges about 1 time per sec . it does not look like a code type of blink.

i noticed if you let the car idle fo about 10 min with pgm fi on it will start to stumble and turn on and off pgm fi light then clear up pgm fi light will go off
and car will run fine .if you drive and engine temp drops the fault will reappear.

thank you for your help.

[87exi]

one more thing.

When car is running good, engine running ,no pgm fi fault light, there is on
led on at all on ecu.

[shepherd79]

check the wirring for temp sensor. wires have atendency to corrode and brake off.

[87exi]

i disconnected my temp sensor and then contact cleaned and re connected it running .
this gave me a code 6 . then i cleared this code and recreated fault.
so i think temp sensor is ok.

temp sensor test it is 5k cold @ 0c, and .273k @ op temp. this is with in limits.

[MessyHonda]

did you try to reset the computer?

[87exi]

yes ecu was reset many times buring troubleshooting.

I installed a ecu that i got from a wrecker today. so far it seems to have fixed the problem,but it is also warmer outside 35F and this problem first occured at about 10 to 15F so i will not know if it is fixed untill the next cold
day.