Automatic Shifting Hesitation & Stuttering

[CB7Nub]

This is weird, I should of gotten it looked at when it first started to happen but now this has gotten worse. Last summer one or twice my car would stutter when trying to accelerate out of a corner. I don't remember exactly what I replaced, think it was the spark plugs and it worked fine after. One time after in the summer I couldn't go into reverse at all (I was in D4 then wanted to go into R to reverse and the shifter would NOT move at all). Since then nothing has happened bad.

Two days ago I was playing in the snow in 2nd gear and last night the car starts to give me problems. I don't have the shifter getting stuck at all. But sometimes when shifting gears it hesitates then goes in the next gear when I lift off the gas for a second or two. I was just coming home from work and it was hesitating to shift but it would shift but the RPM's were going down and I had to push the gas a lot more than usual to get her moving. Like she was being choked. After that I tried to replicate the problem for about 10 minutes just driving around and she was perfect, low and high speeds. Perfectly fine. So it's definitely intermittent. Any idea on what it could be?

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More information on the car and how I drive her that may help.
- I do drive very hard at times (30% of the time)
- I did ONE tracking session past summer at a race track
- I do ZERO neutral drops
- RARELY I brake launch (5% of the time)
- I do mostly city driving (80% city, 20% highway)
- I do warmup the car for at least 15-30 seconds minimum on a nice day, longer when colder
- This is the original transmission on the car and I currently have 215,000 KM on her (I have owned since 173,000 KM)
- My transmission fluid was last changed in the summer of 2011 with OEM Honda ATF (20,000KM ago probably?) (I checked my transmission fluid today before going home from work and it was brown on the stick and looked black in the tranny, it was dark and couldn't really see, maybe I need to just change fluids?)

I did some quick searching and found out it could be a lot of different things.
Here is a list of things I haven't changed since I owned the car:

- PCV valve (This has to be changed I know, but would this affect her like this?)
- EGR valve (This has to be changed I know, but would this affect her like this?)
- Alternator (Usually doesn't really die, my old wagon's alternator lasted till over 410,000KM)

Those are the main things other than the transmission which usually doesn't die. All other regular maintenance is performed (performance mods not included, only I/H/E anyways), I have replaced:

- Spark plug wires
- Spark plugs
- Distributor
- Radiator
- All belts (Timing, balance shaft, PS, AC)
- Water pump
- Fuel filter
- Crank and cam seal
- Air filter

That's all I can remember right now.
Hope that helps out, tried to give as much information as possible.
Thanks in advance!

[dbales]

So the engine feels like its stuttering? Or does the problem feel like its all in the transmission?

[Fleetw00d]

If the fluid is brown, the first thing to do is change it. One drain and fill results in about 42% new fluid. Drive a little bit; a second drain and fill results in about 66% new fluid. A third change would yeild about 80% new fluid. Or you could take to it a transmission shop where they will tie into the cooler lines to change almost completely.

[cloudasc]

Is your d4 or sport light on all the time or flashing at you by chance? Also how old is your o2 sensor?

[CB7Nub]

So the engine feels like its stuttering? Or does the problem feel like its all in the transmission?

Both actually. Well feels like the transmission is hesitating and the engine is stuttering. That was tonight only both together, before I had them at different times. It only got worse until I played around in the snow in 2nd gear.

If the fluid is brown, the first thing to do is change it. One drain and fill results in about 42% new fluid. Drive a little bit; a second drain and fill results in about 66% new fluid. A third change would yeild about 80% new fluid. Or you could take to it a transmission shop where they will tie into the cooler lines to change almost completely.

Sounds good. I what can be done with the fluid, is it safe to drain the tranny fully and put new fluid in? Or when it is drained it doesn't change all the fluid like what your saying above? I heard flushing the tranny is bad for it.

Is your d4 or sport light on all the time or flashing at you by chance? Also how old is your o2 sensor?

No CEL's, no D4, I don't have a sport mode (that's only 90-91).
No unnormal lights at all and all electrical devices (lights, radio, etc) still work fine when the stuttering and hesitation occurs.

[cloudasc]

Random/intermittent hesitation can be caused by an o2 sensor that provides incorrect information to the ecu. Its a maintenence item anyways and if your unsure of the age you might as well replace it. A new Denso o2 sensor can be aquired from RockAuto for under $40.

[trinistylez]

X2 on the o2 sensor.

Ive personally had problems with egr causing hesitation. I took the valve off the manifold, got some carb cleaner and cleaned out the valve. Theres a little dot on the intake side, push it in and clean the carbon out good. Also clean the exhaust side, any carbon you see remove it.

I also got some pipe cleaners and carb cleaner, tried to clean out the manifold through the opening where the egr bolts onto it. My ports are not drilled ao i was unable to do it that way. Put it back together, Start the car, it might idle funny, let it burn off that carbon. Remove egr valve once more and use seafoam down on the exhaust side, worked wonders for me.

Even if this is not your problem, still a good maintenance thing to do imo.

[CB7Nub]

All right, thanks everyone for the fast help!
I've been researching all night and I have found I can replace a bunch of things just to be safe.

Tomorrow I'm going to get:

- ATF changed with OEM Honda ATF-Z1
- O2 sensor changed with NGK/NTK/Denso O2 sensor
- PCV & EGR valve replacement (OEM Honda)
- Spark plugs replacement with NGK Iridium
- Spark plug wire check (I will check, they are about a 1 year old)
- Oil spray (not related at all)

I may get the these items checked or replaced as well, which I should anyways. But may not all in one day.

- Fuel injector check
- Air filter clean or replacement
- Vacuum leak check (don't think there are any)
- Seafoam or similar to clean out the system

Other things that I have heard of when looking engine hesitation in our cars are (more severe):

- Valve cover gasket
- Spark plug o-ring gaskets
- Head gasket / compression test

I will post an update, hopefully she will make the trip to the shop!
Else CAA will be getting a call.

[Fleetw00d]

To answer your earlier question, when the transmission is drained, you only get about 2.5 quarts out of about 6 in the transmission, so a single drain and fill only replaces 40% of the fluid as I described. Make sure the shop does something to change most of the fluid.

[trinistylez]

good luck with the oem egr replacement, even with the aftermarket ones, they range $300-$400+ over here

[Darius.27]

My 93 accord has a similar problem with stuttering. The funny thing is that mine was fine until I got in a wreck last night. The wreck knocked off my front bumper, busted my headlamp, dented my radiator support a little. I was able to drive away from the accident(of course after reports were filed lol) last night but the problem reared it's ugly head on the way home tonight.

[EsperHamid]

where's your update :P