Idle revving, 91 Honda Accord


#1

We have a newly acquired Honda wagon, 16 valve, PGM FI, auto trans, that revs while idling. It sometimes does it when cold buy also hot. It increases it’s idle to 1500 and drops revs to 1100 about every 6 seconds. Normal idle seems high at 110.
Any ideas?


#2

The first thing to look for with a surging idle is a vacuum leak. You need to check all vacuum lines, the intake manifold, air intake snorkel, etc.


#3

Bingo, there was a fitting on the FI housing and I found a hose that was hanging, plugged it in, revs drop and all seems to be fine. It took, 1 minute to find and fix.
I love this place, thank you cigroller.


#4

So glad to hear it. I’m sure I’m right every once in a while though people rarely report back so we never know. So thanks much for taking the time to report back!