I have noticed that the tach appears to malfunction when the engine gets near 3000 RPMS or above. The tach needle begins jumping all over the place.

The car starts fine...and appears to run fine. About a week ago the check engine light did come on for a short trip home from town...but then was off when I restarted later and hasn't come back on. Not sure if there is any relatin...but there seems to be no other symptoms at this point.

Does a malfunctioning tach like that affect the transmission in any way in this year/model? Would it do any further damage if not fixed right away?

Thanks for the thought and advice,
AJ

 

In my experience, a malfunctioning tach may signal possible ignitor fault, bad spark plug leads, coil, plugs, or all of above. It may be followed by failure to start at some point. Better have some diagnosis, if problem can be reproduced. Don't wait as bad plugs/wires can damage the coil or ignitor.

good luck

 

I agree with TexasHonda. My bet would be igniter (in the distributor) or the coil. The trouble code should help narrow down the problem.

 

Just some additional info...I jumped the diagnostic connector and it looks like the blink code was one long and 2 short. I have a CEL Code list and this is what was listed:

12 EGR - exhaust gas recirculation lift valve

Does this code make any sense or help clarify the tach issue I am having?

Thanks,
AJ

 

Sound like there might be two issues.

I'm with TX and Redbull, the tach acting up when this happens is something with the coil or ICM. There are tests that can be done on both. The coil, you might want to preform these when cold and also after the car has run for some time.

The ICM, well the same except testing when warm is hard to do. Some stores have a tester that can also do this. One thing while looking at this, be sure the wires to the ICM are in good condition...Have seen poor connections, broken insulation on one or more of the wires to the ICM be an issue.

EGR, for now I'd keep it in mind but if it does not come back.......

 

EGR code 12 occurs when ECU detects mismatch between commanded EGR lift position and desired lift position and is unable to correct w/ addition/subtraction of vacuum supply to EGR. It could be problem w/ vacuum delivery (damaged vacuum line or EGR switching solenoid) or sticking EGR valve.

Check EGR valve movement w/ hand vacuum pump or oral suction to see if valve moves easily. Apply vacuum w/ engine running. Engine should try to stall as added air leans out engine. If it's stuck open or closed, you may be able to free w/ throttle body cleaner and air jet. Mechanical access for cleaning is impossible to my knowledge due to design of valve (closed system).

Warm engine fully, and check for vacuum supply to EGR w/ rpm at about 2000. If no vacuum, the vacuum switching solenoid may be faulty. Check for switching w/ 12v directly applied to solenoid. Check vacuum lines carefully.

good luck