Hi guys and gals,

The Honda forums are... strange. I wanted to ask y'all a question about my folks' Honda Accord, 1992 model.

Now, the Honda - it has a rough idle and shakes - and it has for a year (my folks' car, and they aren't car-people), and now the mileage is appearing to suffer. I'm going to help my Dad track down whatever trouble is going on. The DIY oil change we did last week mellowed the engine considerably, and I wondered why - any thoughts?

The rough idle is extremely regular (like the engine is unevenly weighted), and I suspect something in the ignition. Would a failed plug or wire (or distributor, or its cap and rotor) lead to a rough idle, with no smoke? I notice a gassy smell, but no irregular putt from the tailpipe.

The plugs have been in there for like 40k miles. And the wires are original, as far as I can tell - the car's got 170k miles.

I think I'll invest in a Haynes manual for the Honda, regardless. I love my Volvo Haynes!

Thanks!

Ari

I have a Haynes manual for my Toyota. It's just as inscrutable as the one for the Volvo. How many miles does the Accord have on it? My old Toyota started getting uneven compression from ring wear long before it started smoking - say around 125,000 miles. The idle has been rough for most of its 3 engines and 329,000 miles.

Check the Rear Motor mount on the Accords, They go bad frequently.

Like the Volvo 700 series, they are gas Mounts that stiffen as you accelerate. dumb idea
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'75 Jeep CJ5 345Hp ChevyPwrd, two motorcycles, '85 Pickup: The '89 Volvo is the newest vehicle I own. it wasn't Volvos safety , it was Longevity that sold me http://home.no.net/ebrox/Tony's%20cars.htm

While it's idling, pull the plug wires loose one at a time to see if there is a particular cylinder that's dead regardless of whether the wire is on or off. If you find one cylinder to be the problem, then you can zero in the reason (bad distributor cap, bad wire, bad plug, burnt valve, bad injector, etc, etc).

I know this is ill-advised on Volvos - are Hondas different in this regard?

Ari

I was never told it was ill-advised on Volvos, so I don't know about that. I do know you want to keep you front lower torso area away from the metal fender when doing it.

So funny!!

Not if you are the victim of the Voltage... I've been there.
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'75 Jeep CJ5 345Hp ChevyPwrd, two motorcycles, '85 Pickup: The '89 Volvo is the newest vehicle I own. it wasn't Volvos safety , it was Longevity that sold me http://home.no.net/ebrox/Tony's%20cars.htm

Would you check the plugs SpazMan? For me?

Will do - but later in the week, since the Honda is my folks' daily driver (and, as of now, is on the way to my Dad's job). I've got an Autozone shopping list for their car that includes some Bosch copper plugs, as well as other basic tune-up items like an air filter.

I'm curious - do you think the plugs are at fault?

Ari

If the plugs are not at fault it may be time for a compression test.

Rough Idle is a symptom of faulty compression and if you had actually fouled a plug the mileage would drop by 40% at least.


Good Luck!!!

Ack!

I'm thinking, and I'm sure that the valves were adjusted right before this rough idle began. Could bad valve timing do this?

The mpg loss is slight - highway miles at 32/gallon, rather than 36-40.

Ari

Vac leak? Also ohm out the air sensor/meter and o2. From all my yota work I know if your compression is good your going to have to troubleshoot the whole efi system. The rough idle and loss of gas leads me to bad mixture. So I'd go to air meter and o2 sensor. If this car has these??

Yeah, and recheck the valve timing. That would do it.

I believe this car has a MAP sensor, not an Air Mass Meter (my '90 and '94 Accords didn't have AMMs.) Perhaps that is bad and is causing a rich mixture...

Although the factory service manuals are best, Haynes is OK and Chilton actually make a "Total Car Care" manual for the Accord that is pretty good. You can pick up a copy of those at most large auto parts stores.

Andrew S.

'91 744