So this just started today. Anytime the tachometer passes the 2600 mark (regardless of in gear or neutral) it starts waving back and forth all crazy like. If it's just slightly over it moves about 100-200rpm but when it's around 3000 it waves back and forth between 1600-2600rpm. When I pass what I would estimate to be 3500rpm it just drops to 0. This isn't a huge deal, but I wouldn't mind finding out the cause, and if possible a solution!

Thanks a lot.

 

It is either the ignition control module, the tachometer, or the wiring between the two.

The ignition control module generates the tachometer signal. It is in the distributor. You can pull the distributor cap and check that the four wires are clean and secure on the ICM. One of the wires goes to the tach (blue wire on a 5th gen accord).

If wiring checks out ok, then I would swap the ICM with a used one from a junkyard(less money). It is a simple repair. Just keep the four wires in order.

 

I was told it could also be the ignition coil. My car has had problems starting lately, and now as of today will not start at all.

 

I had my 94EX exhibit tach problems, which turned out to be plugs. I think any damaged high voltage ignition problem may cause tach problems. Clean or replace plugs. You should check for sparks jumping around at night after spraying the wires w/ water. If you see lots of sparks, the plug wires need replacing for sure. Distributor cap and rotor are also potential sources of spark loss.

good luck

 

Hopefully by now you've got the issue fixed...but just in case... I recently had the speed sensor replaced on my 95 Accord due to fluctuating speedometer...then the odometer quit working...and the check engine light came off and on....tach went crazy..On mine it was located on the bellhousing of the tranny...very little room to fit my hand in and change it.

 

believe it or not, i haven 't fixed the problem yet. I've been car-less for a week. I ordered an ignition coil online thursday night. Friday morning I discovered my car would not start at all. So now I've been stuck waiting forit to arrivebecause I couldn't cancel my order. I could have bought the part for $10 more at my local Honda dealer.

Anyway, wires & plugs were changed about 1000 kmago. the old ones were in rough shape but they weren't causing my starting issues. I also thought it might have been the fuel filter. My shop manual says that if you have problems starting on really hot or cold days it could be related to that. Really, it was only acting up on the hotter, dry days. I ran some 94 octane gas through it a couple times and coincidentally my car started easily every time. I thought the problem was fixed and then the last few days before it died I was getting rough starts again. I was going to investigate further and the next day the tach went nuts. That led to my decision to order the ignition coil. the coil wire going from the distributor to the coil looksin decent shape, and I know the distributor was completely replaced a couple years ago. (prior to me owning the car) so hopefully it's not that and this new coil works.

It's been an adventure. Coil comes in sometime tomorrow, so I'll post up my results.

Cheers.

 

So I installed the coil, tried to start. Took about a minute before the car actually started. The tach is completely dead now. I'm going to go check the ICM. I'm just kind of afraid to take the car out anywhere like a junkyard to get parts because I don't want to get stuck there. I'm out $100 from the coil due to poor internet advice (from elsewhere).

 

If you have a volt meter, you should turn the key to the II position. Pull the plug going to either the distributor or the coil (both get power from the same source). The yel/blk wire should have 12V to body ground. You might as well diagnose the problem before you throw more money at the problem.

 

i pulled the cap off the distributor to check the wires, but two of the bolts have now broken off so i can only get one screw back into the distributor. they are too short to pull from the other side, and I have no other ideas on how to remove them?!

 

You are going to have to remove the distributor and drill them out. If you are not comfortable with that, then take the distributor to a shop and ask them to do it.

Use a drill bit slightly smaller than the bolt (use the open hole in the distributor housing as a guide). Drill dead center and straight down the axis of the bolt.

You will have to pick up a tap that matches the thread pitch. Use your good bolt to find out the thread pitch (it will definitely be a metric thread). The tap will recreate the threads, and is why you use a bit slightly smaller than the hole.

Put a bit of anti-seize on the threads to prevent this from happening again.