My 94 EX has a code 14 that just won't go away. Symptoms are erratic idle and stuttering when driving that results in an intermittent loss of power followed by a surge seconds later. I've replaced the IAC Valve twice, cleaned the throttle body and bled the system. I am out of ideas, anybody with similar problems?

 

Have you checked the wiring to the IACV?
Have you checked on the FITV?
There are a couple of writeups on both in the FAQ at the top of the page.

 

You should get battery voltage at the iacv with the ignition on. If that checks out it could be your ecu.

 

Checked IAVC w/Multimeter and FITV. Don't think it's my ECU after pulling it out and looking over the board.

My problems seem similar to this:

https://honda-tech.com/forums/honda-accord-1990-2002-2/1994-accord-ex-misfire-stuble-under-acceleration-2895754/

But no resolution was ever posted... as always...

 

The OP in that thread you linked described classic O2 sensor problems. An out-of-spec O2 Sensor puts the IACV through all kinds of gyrations trying to adjust to the faulty demands for more/less air in the air-fuel ratio. The Code 14 is strange, but you should at least investigate the O2's, especially if they are are very old or original.

 

Check for continuity on the ground side going back to the ecu.

 

Bought a multimeter but domt have a clue how to use it. How would I check?

 

Friend checked FITV and IAVC to be clear, just got my own multimeter today.

 

Turn the ignition on and check for battery voltage on one of the pins in the connector going to the iacv. If you get battery voltage, check for continuity from the ecu connector after disconnecting it to the other pin on the iacv that doesn't have battery voltage. It will be pin A9 at the ecu.

http://technet.ff-squad.com/wiring.obd1.htm

If you get continuity from the iacv connector to the ecu at pin A9 then the only possible cause is the iacv is bad or the ecu is bad. It's that simple.

 

i had same issue but i was running a Hondata chipped P28 in my accord. turned out to be a bad ECU. put another P28 in swapped the hondata over and it went away.

 

UPDATE:

Checked the pins and all seemed well, replaced the IAVC before buying a new ECU and problem seemed to be fixed. Drove around for a couple days, no problem. Day three rolls around and now I'm noticing a real decrease in power from 1000-3000 rpm, then a code 12 appears (EGR). Bought another EGR valve and installed... then the code 14 came back. Not as severe, but definetely present. Stuttering occured on my way to work, but not on the way back. Code 14 also disappeared. Gonna try cleaning out the throttle body one more time and post details.

 

UPDATE #2:

So symptoms are slowly coming back to what they were before. Just yesterday, the car started acting up as I pulled out of the driveway, but after shutting it off and restarting, car ran fine no problem. Leaning towards ECU now, but does anyone think it can be the Fuel Pump? Heard that a failing fuel pump can lead to stuttering and etc. I have also noticed a decrease in power in lower RPMS, especially in 1st. Gonna look into have the fuel pressure tested. More to come

 

preluder mentions some very similiar symptoms in his first comments here: https://honda-tech.com/forums/honda-prelude-4/symptoms-bad-fuel-pump-528698/

 

Just keep replacing things. There's really no point in testing anything since you obviously don't really want to fix the problem.