1987 Honda Civic Tachometer

rough

#1

I noticed one day my tachometer needle was all the way to the right past 8! The car was not whining and I was in the correct gear. What could be wrong with it? Sometimes it will start working and accurately reflect the rpms, but only for about a mile. The mechanic said the distributor assembly was filling up with oil. He said Honda had problems with this a while back. When I told him it was idling rough at the stoplight, he said both the tach and the rough idle could be fixed with a new distributor assembly. He put in the new distributor assembly, but neither the tach or the idle were fixed. I should mention I am a flight attendant and this is a commuter car I keep at the airport. I have a quick disconnect on the battery, so I disconnect the battery when the car will be sitting for three days or more (it has a slow electric drain). The mechanic was very nice and said he won’t charge me for the distributor assembly until he fixes the problem the next time I can leave the car with him. What could be causing the rough idle and the tach not to work?


#2

There could be MANY things causing the rough idle…bad gas…vacuum leak…spark plugs…sparkplug wires…Very difficult to diagnose here.

As for the tach…forget-about-it…A useless instrument unless you’re racing. I wouldn’t spend one dime getting this fixed.


#3

I was going to forget about fixing the tach and the rough idle until one day after I had been in the store for about five minutes and I came out and couldn’t start the car. The engine acted like it wanted to start but couldn’t get enough fuel or air. The starter motor was working. After letting the car sit about five minutes, I was able to start the car. I had to rev it up to keep it going while I was sitting there. Once the car was moving, it seemed fine. The mechanic said the symptoms of difficult starting and tach not working indicate the distributor assembly needed to be replaced. After he saw the oil in the distributor, he was almost certain that was the problem, but it didn’t fix the problem. Any more thoughts?


#4

Is this thing carbureted or fuel injected? Hondas of this vintage are very different beasts depending on their fuel delivery system.

I’m not sure what all comes with a complete distributor assembly for this thing, but the next things for your mechanic to check would be the coil and the igniter/ignition module. The intermittent no-start condition would make me suspect the ignition module, which would explain both problems. It is just as likely, though, that it could be a couple of unrelated problems. If the distributor was filling with oil it probably did need to be changed (although maybe he could have got away with just changing some o-rings inside it).


#5

Thanks for the info. I don’t think it is fuel injected. I have the Chilton book with the car which is not here at home. I don’t know if I mentioned that I disconnect the battery when I leave it parked at the airport. The mechanic had said that the computer has to reset itself every time I unplug the battery, and that the idle has to reset itself. He said that could be the reason it idles so rough at stop lights. I was reading another posting where someone said the idle will have to reset itself when the battery is reconnected. But how long should it take? Two miles, two hours, how long?


#6

The idle having to “relearn” does not apply to a carburetted car, and I don’t think it even applied to the early fuel-injected Hondas. I think if the tachometer problem can be adequately explained, your car probably just needs a tune-up including a carburettor cleaning and adjustment. If I were your mechanic, I would try hooking a service tachometer up to the tachometer port. If it also goes haywire like your tach, I would continue investigating the ignition system, but if it reads normal I’d chalk it up to a bad tach (which like Mike said, is nothing to worry about) and have him start looking elsewhere.

Carburetted cars really don’t like to sit-- if you let them sit for more than a day or two, the gas will usually evaporate out of the carb, which will lead to hard starting and sometimes rough running. I still think you need a tune-up, but you might try driving it through some more normal conditions to see if it works better then. Also, if you don’t drive this thing very many miles when you do drive it, you might have some old and/or bad gas that might just need to work its way through.


#7

Thank you so much for your comments. The info. you have given me will help me talk with the mechanic. Once the problems get fixed, I will post the results.