Small weird "backfire" - Civic LX 97

[rednobodyv]

Hi guys,

I have a problem with my Civic.
Its a
1997 Honda Civic LX
5spd 1.6L ~ 155k


When I accelerate at low revs, 5th gear @ 2500rpm ~ 45 mph.
I feel that the engine is dying... the revs are dropping out of nowhere (i keep constant acceleration, no more and no less)
The revs just keep dropping till it feels that the car is "choking" and than it takes off again normally reving up. *all this time acceleration is kept constant.
It did this a few months ago, I did a tuneup on it and it didn't do anymore.
It started doing it again a few weeks ago.. however yesterday was different.
I was at around 3000rpm, and revs started dropping again... It dropped to about 2600rpm and than I heard a small "backfire" and felt something underneath the driver seat (thru the floor).
I put it in neutral, back in gear accelerated and it was okay.

Today, it did the same thing... Around 2800rpm in 5th gear, revs started dropping again I kept acceleration steady, wanted to see what happens.
I had about 5-6 noises under the car.. the "small backfires," and felt the same thing under the driver seat.. all this under 15 seconds.
I let go since I was abit concerned.. so i put it in neutral, waited a few seconds.. putted back in gear and accelerated, no problem.

This only happens when im at low revs, accelerating slowly.
If i put it in gear and accelerate hard, no problems.


I know what you're thinking.. "just drive fast everywhere.." but eh..

Anyway, any comments that might help out are welcome.

I added a pic at the top with the red glow around the area that i heard the "small backfire-like" sound and feel something.


// also, check engine light is NOT on

thanks.