91 Accord Automatic RPM Spiking Problem

[Vincevox]

`Hey All,

So recently I been having a problem with my cars accelerations where the RPM would drop or spike all around.

Here is a video of what exactly is happening.



*https://youtu.be/qwXtBw8hmMw

So before hand it was running fine and no fluctuation or spiking of any type. So as far as I know I had only just changed the distributor because the old one was leaking due to a old o ring seal. So after that it started up fine and actually had a more kick to it, when I would first start off. But as I would go through the the 3 to 4 automatic gears it would spike and or drop on me and just struggle.

Right now I am struggling to understand if it is because of the new distributor replacement? or the timing or grounds are messed up or the VSS (Veichle Speed Sensor) or even a leaking of air..

Please let me know what you think and any experiences that have happened to you!

P.S

I have tried my best to research but it was something diffrent from my situation where others have had only 100 rpm jumps or small spikes but for me it is a big spike from 1500 rpm to 5000 rpm or from 3000 rpm to 1000 rpm!

[dhill_cb7]

Hey your video did not work for me. Not sure what is wrong. Just says "an error has occurred. "

[Vincevox]

Originally Posted by dhill_cb7

Hey your video did not work for me. Not sure what is wrong. Just says "an error has occurred. "

Try clicking the link I could not figure out the problem when I tried to fix it sorry!

[Raf99]

Can't say i've seen that before.....

Obviously the engine is not doing that, so it would appear to be a speed sensor thing. Almost like it's skipping teeth for a second. I really don't know though....

[fleetw00d]

As Raf99 said, the engine isn't jumping all around with the tach, so it is likely an electrical problem. Most likely would be the ground under the thermostat housing. Did you install a new distributor? OEM or aftermarket?

[deevergote]

From my experience, a jumpy tach is usually the result of a failing igniter. If that is the case, the igniter will likely fail completely very soon. There's no way to tell if it's going bad by looking at it, and no way for the average person to repair it that I am aware of. Replacement is the only fix. I used to get them from a junkyard and carry a few questionable spares at all times. They're not cheap (or at least they weren't when I had the issue... they may have come down in price since.)

Ground issues are definitely possible as well. You can address ground issues by ensuring all ground points are clean and tight. If you do that and the problem persists, the igniter is the most likely culprit. You could buy a new one in preparation for failure (replacement is a 5 minute affair, needing only a screwdriver), or you could take your chances and ride it out until it quits. I'd take a look on RockAuto.com to see how much a replacement would be (it may also be listed as "ignition control module").

[Vincevox]

Thank you all for such a quick response!

Well it is a newer distributor and its actually an OEM it is off another cb7.

I have not checked all grounding points which I will look into!

I also drove it today on the freeway and on the city roads , the problem persists when I try to accelerate to 4000rpm or above it just jumps all over and when on the freeway when I keep it at a constant speed and rpm it acts normal.

I will check that igniter if anything and see if that is the problem and replace it ASAP.

Again, Thank you all for your quick replies!

[deevergote]

New distributors don't necessarily come with new igniters or coils (for cars like yours with internal coil distributors.) Unfortunately, there's not much you can do to check it. Unless you manage to find some information that I'm unaware of... in which case, please share!

There's also a chance that your cluster is going bad. It's not very common for that to happen, but as these cars age, new problems tend to crop up.

[Vincevox]

UPDATE!

So we just replaced the VSS (Veichle Speed Sensor) and that fixed it right up! No fluctuation and speedometer is not spiking!

Thank you guys so much for your support and help!

[Raf99]

I bet ya worn teeth on the VSS could do this. Any load on the teeth cause it to skip.

Say, Deev, how does our speedometer get it's reading? Is it:

VSS gear -> electrical connection -> ECU -> ECU applies power to dash cluster to move a motor (with an arm attached) ?

[deevergote]

I believe so, yes. But I didn't think the VSS would produce a tachometer malfunction. The VSS has no idea what the engine speed is. Speedometer, certainly, but the tach is usually a separate issue (and unless I missed something, as I didn't watch every second of the video, the tach is what was freaking out.)
I could be wrong, since I've never had a VSS issue myself. I have had a failed igniter on a few occasions, though, and that caused a wacky tach each time.

[Vincevox]

Hey so false alarm with the update of fixing it , the rpm is not jumping anymore but the speedometer just decided not to work and sometimes when I end up accelerating on the free way it does jump around again?

So yeah still having problems again :/

[deevergote]

Your cluster may be on the fritz, then.

[Vincevox]

Hey all so what ended up happening was that the VSS was broken so the wire broke off and my harness then showed terrible wear and i ended up replacing the whole wire harness so it was replaced and now it is all good now!

[deevergote]

Glad you figured it out!
A damaged harness would definitely cause all sorts of weirdness.