Hi:

Regardless of load, speed, or rpm, my 1995 accord EX 2.2 VTEC automatic runs rough (stuttering, sputtering) at cracked throttle (approx 1%-5% open). At 5%-100% it runs fine.

The car is all stock and has 180,000 miles.

The check engine light is not on (but verfied that it is functional). I thought it might be the O2 sensor, so I checked it with the volt meter according to the Hanes manual and it appears ok. As a second check, I disconnected the sensor and ran the car and the problem persists.

Nothing has been done to the car recently. The problem started suddenly without provocation.

I looked at the vacuum lines and did not see anything suspicious.

The car idles fine and runs normal at >5% throttle.

Does anybody have an idea as to what could be the problem here?

Rob

 

No CEL....all reg maint items up to date (cap, rotor, plugs,ect). A few ideas of where to start, most don't cost much.

A good TB cleaning, along with inspecting/cleaning/adjusting the FITV and IAC.

You say it doesn't matter about load and that but what about engine temp....all the time or just when the engine is warm.

 

Good question - I forgot to mention that it runs fine when it is cold. After about two or three minutes it starts to act up and then continues until engine is cooled down.

 

Another clue...two to three minutes isn't enough for the egr to come into play, so cleaning the ports is out (?). So I'm going to go with the FITV and or the IAC needs a bit of cleaning/adjusting. Should be a "how to" in th DIY section.

Again, the other maint items are up to date?