Surging tach while at 55mph

[AccordAnimal]

There it is. I am doing 60-65 mph down the road and my car bounces between 2700 and 3000 RPMS.

1. It's not a problem with the Tach becuase I can hear the engine race up
2. This only happens in the warmer weather
3. Sometimes it triggers my CEL and sometimes it doesn't
4. It's annoying as hell
5. I was thinking it could be my O2 sensor?
6. I ran the diagnostics on it and pulled an EGR Error, so I cleaned it and got WAY better mileage but the pulsing is there. Also, it is not constantly pulsing it will stay at 2700 for about 30 sec, then just to 3000 then down to 2700 then up to 3000.

Any Ideas?

[xaxis360]

Where does the car tach when its cold and driving normally?

[CBL]

is your car a manual or auto?

[AccordAnimal]

I have noticed it reving at about 2200 RPMS when it is cold, and then surges sometimes when it is idling, only sometimes and the high "cold idle" is spiratic as well. Then it drops down to where it is suppose to be. My Car is an automatic.

what's my ivac and tb?

Thanks,
Adam

[CBL]

if it happens only while doind 40mph, my guess is your trans is going out. But you could thry to clean your (tb) throttle body and your ivac (electronoc air conrol valve).

[AccordAnimal]

Do you guys know of a DIY on that? Or maybe I diagram

[91AccordLX]

yeah clean the IACV out, its right there on the intake plenum, there are like three bolts holding it in..you will see it easily..it has an electrical connector that plugs into it.....and what you need to do to clean it is take some cotton swabs and clean the little mesh part out, but dont break the mesh screening. also you can go ahead and spray some TB cleaner inside it too...see ya.

[AccordAnimal]

Thanks for the help I am gonna give it a try and see if it works. It was doing it something terrible today

[art vandeleigh]

check the ground wire that is connected to your thermostat housing before you go messing with the IACV. even if it is a little bit loose it will cause a jumpy tach. ask me how i know

[clarksterdotcom]

check the ground wire that is connected to your thermostat housing before you go messing with the IACV. even if it is a little bit loose it will cause a jumpy tach. ask me how i know

ill bite...."how do you know?"

[art vandeleigh]

oh sorry that was meant as a rhetorical statement. but i had similar problems of a jumpy tach. i replaced the coil, did help, replaced the ignitor, didnt help. then found out that the loose ground on the thermostat could cause the problem...it was only loose ever so slightly. fixed the rpoblem. i spent over $170 and all it was was a loose ground