1991 Accord Engine is Revving in Neutral

My wife has a '91 manual transmission, Accord that just rolled over
200,000 miles. Lately, when she has been in neural, the engine will
start to rev up to about 2000 rpm and then drop back down to about
1000, and continue this loop until she is in gear and drives away.

At first, this was an intermittant problem that seemed to go away after
the engine warmed up, but lately it has been happening longer and
longer, at times even when shifting gears.

Anyone know what might be causing this and how we might be able to fix
it?

 

Sounds an awful like a vacuum leak.

 

====================

How full is the rad, how full is the reservoir, and have you recently
done any work on the cooling system?

Is the temp guage stable? Good cabin heat?

'Curly'

 

We replaced the radiator just a few months ago (Aug or Sept, I can't
remember) and we haven't had any problems with the temp gauge and cabin
heat is fine. I will double check the radiator and reservoir, but would
the rad cause the RPMs to jump up and down? I had thought it could be
some sort of sensor, but I'm curious to know what you're thinking it
could be since I hadn't considered the cooling system being the
culprit.

Thanks for your post -- anything to help narrow it down.

 

We replaced the radiator just a few months ago (Aug or Sept, I can't
remember) and we haven't had any problems with the temp gauge and cabin
heat is fine. I will double check the radiator and reservoir, but would
the rad cause the RPMs to jump up and down? I had thought it could be
some sort of sensor, but I'm curious to know what you're thinking it
could be since I hadn't considered the cooling system being the
culprit.

Thanks for your post -- anything to help narrow it down.

 

We replaced the radiator just a few months ago (Aug or Sept, I can't
remember) and we haven't had any problems with the temp gauge and cabin
heat is fine. I will double check the radiator and reservoir, but would
the rad cause the RPMs to jump up and down? I had thought it could be
some sort of sensor, but I'm curious to know what you're thinking it
could be since I hadn't considered the cooling system being the
culprit.

Thanks for your post -- anything to help narrow it down.

 

O2 sensor...... 92 Accord did it.... 98 Accord did it.... Same fix.