2007 Honda Fit Sport - Dry Heaving while idling

My 2007 Honda Fit (sport) has been having this problem for a while (6+ months)…
It used to happen both while moving and idling.
The car will suddenly make a jerking motion (like a lesser version of stalling a manual transmission car)
No real sound involved, just the car shakes, sometimes a few times in a row. The engine does not stall, nothing else happens.
Not being a really knowledgable car person, I took it to a shop… they did a massive tune up on it (second time spark plugs were replaced in 30k miles)… $500 or so bucks later, the car works fine again… for 6 months… then it comes back, the “dry heaving” motion now only happens while idling… like sitting at a stop light. It does not happen in neutral. It does not happen in park. If it happens while moving it is much more subtle than it used to be.
Car has 158,000 miles on it. Purchased it used at 89,000 miles.
It has no codes, and has been checked a few times.
It is an automatic transmission.
Has anyone else run into this issue? Any ideas?

Are the RPMs fluctuating up and down during this, or is it just stumbling as though it’s about to stall?

No change in RPM… just the shaking motion

Is it only when running the AC?

You may be experiencing an intermittent misfire that is a known issue with some Fits. If the misfire is infrequent enough it won’t set a “check engine” diagnostic code, making it difficult to track down. Some Fit owners have reported bad coil packs as causing intermittent misfires. You could also try some of the troubleshooting steps in this post:


Presume the diagnostic codes have been read out, and nothing. If that’s not yet done, do that first. Post any codes it has here.

I agree w/ @jesmed1 , the symptom sounds like a misfire. For some reason the explosion which is supposed to consistently occur like clockwork, cylinder to cylinder, occasionally isn’t for some reason. Try this. Put it in idle in N, set the parking brake, and take a dollar bill and hold it from above, near the end of the exhaust pipe, so it is waving in the exhaust output. On a properly running engine, the dollar bill will never move rapidly toward the tailpipe. It will move to and fro as the engine goes chug-chug-chug, but it will never make a rapid dash toward and even possibly touch the tailpipe. If yours does move toward the tailpipe in this experiment, that’s a definite sign of a misfire or similar problem.