89 accord lxi coupe rough idle help please...

[DaveEye]

hi, i just bought the car 2 days ago. it runs great, but the idle is kinda rough. even after warm. the car takes off fine with no hesitation or anything. car was sitting for a couple of months before i bought it and have only driven it about 10 miles so far.

should i start trying to diagnose the problem or drive it some more and see if it gets better? my fear is that the idle may be a problem for the smog inspection, which i need to do soon in order to register the car in california.

thanks in advance!

[HondaBoy]

is it really the idel, or a motor mount problem? as you say, its an idel problem. how so do you mean it is rough? like not smooth, erratic rpms? cheapest thing to do is check your vacuum lines on the intake manifold. any that have a hole in them of any sort would cause some rough idel, but not neccesarily a driveability problem. anyways, elaborate on your idel problem.

[Oldblueaccord]

warm try to get it around 900 rpms. There not the best idling cars we all have the same problem. Run the AC and see if that helps it helps mine,least in the summer months.


wp

[DaveEye]

regarding the rough idle, i mean it shakes the car. it doesn't hunt up and down, it just idles rough. i don't know how else to explain it. it is definitely like having a vacuum line issue, but there is no hesitation under acceleration.

also, at higher rpm like around 1,000, it is very smooth. my tach cable is shot and the needle bounces around a lot, but i'm guessing idle is around 600-700 rpm when warm. this is the only area of problem. again, no hesitation and the car does not die or sound as if it wants to die.

it's almost as if i turn up the idle speed a bit it would be fine, but i am not sure what the spec is for warm idle.

thanks!

[Oldblueaccord]

well the specs should be on a stricker under your hood for your year car. The tach is a wire? maybe you meant that was bad somehow. That needs to be fixed or cut off since it comes of the high side of the coil could give you a nasty shock or short to something.

Some of the auto tranny problems are the torque convertor will not slip enough at idle so the shaking happens and yes check for bad, worn or missing motor mounts.


wp

[DaveEye]

my car is a 5 speed so definitely not an a/t issue. i have to figure out how to check engine mounts, but i will try to look into that over the weekend and report back.

if the engine mounts were worn, wouldn't the engine/tranny move under acceleration and therefore i could feel it through the shifter???

thanks again for the great replies and wisdom on this topic!!!

[shepherd79]

have you done anything to the engine?
if you haven't you should try running Seafoam in the fuel to clean up the injectors. run it 2 full tanks. it should do the trick.
after that chage the spark plugs, spark plug wires, distributor cap and rotor.
plug and wires i would recomend NGK brand. It is OEM brand and you can find them almost everywhere. As for cap and rotor. Aftermarket replacemnt ones don't last long and they are crap. just got to a dealer and get them from there. Trust me they would last longest.
also, check the timing.
if the idle continue to be ruff even after that, you can always bump it up a little.
Idle should be at 750rpm steady with or without AC.

[DaveEye]

regarding sea foam, i was going to use that just before i tool the car in for the smog inspection and run it through a vacuum line through the engine intake.

i had another post regarding a tachometer needle that kind of bounces around a bit and found out that the tach is electric so it isn't a cable mechanism that is bad. some posted recommendations had to do with replacing the coil, so with the tach issue and this somewhat rough idle, maybe there is a connection.

still need to check engine mounts and then go through the plugs and wires, but i think with all the suggestions i have some great ways to try and resolve this issue and probably make the car better anyhow since it is 18 years old and it seems like it still has almost all of the original parts.

thanks again for all of the great recommendations. everyone at this forum is awesome!!!

[MessyHonda]

regarding sea foam, i was going to use that just before i tool the car in for the smog inspection and run it through a vacuum line through the engine intake.
i had another post regarding a tachometer needle that kind of bounces around a bit and found out that the tach is electric so it isn't a cable mechanism that is bad. some posted recommendations had to do with replacing the coil, so with the tach issue and this somewhat rough idle, maybe there is a connection.
still need to check engine mounts and then go through the plugs and wires, but i think with all the suggestions i have some great ways to try and resolve this issue and probably make the car better anyhow since it is 18 years old and it seems like it still has almost all of the original parts.
thanks again for all of the great recommendations. everyone at this forum is awesome!!!

seafoam helped me pass smog in california.....i ran it down the carb since its carbed...and i felt it was pulling harder...i also put some in the gas tank
i ran the car HARD...like 80mph for like 15 mins and then i took it in ....it passed...so i was happy

[DaveEye]

just as an fyi at this point, but while driving the car last night, the idle smoothed out for a little bit. i noticed that at that time the tach needle wasn't bouncing around. so, i am guessing it is an issue with the coil and will start there, as the smoother idle only lasted for a brief moment. as it is saturday, i finally have some time to work on it.

[shepherd79]

don't forget to look at HOW TO, there is one for aftermarket coil replacement.
it is easy to do, and it is cheaper than buying stock coil.

[njpeter]

well that was some great stuff on the ignition coils..where's my jay-cee whitney catalog now.

On the issue of motor mounts..what's the deal..my daily driver ( yanno, that old gray beater) failed for "broken or loose" motor mounts..I understand the front mount is actually some kind of damper filled with oil?

Hate to say it but after making a fillet out of my hand on a heat sheild while changing a PS steering hose..I may have to hang up the wrenches for a while. I was sniffing around for a (gasp) later model accord ( gee whiz guys..there are no low mileage example around NJ anymore). Anyhow, a visit from the motor mount guru would be appreciated. BTW, automatic.

[88Accord-DX]

Yep, you guess it right. That front motor mount at the bottom is fluid/oil filled. Runs around $45 give or take.

[njpeter]

I took a dive into it yesterday and jacked the engine a bit to see what might be broken, turns out it's the easy one by the timing belt..checked my "junkyard and that mount was broken on every single car!, I should have just filled it with wire screen and silicon goo, but I went and bought a new one ( need some kind of receipt for the inspection)..paid like $75 for it..had to hunt around too...local dealer didn;t have it and couldn't wait for a shipment from majestic. tried to fix the idle problem too...I'm taking anotehr run at inspection int he middle of january ( I'm going to my trailer in nm for a week to get away from all of this and do a little fishing) if the car fails I'll be selling that brand new motor mount and just getting anotehr car..at 240k miles there are just too many little things that need work ( timing belt too) at 49 now I'm a bit stiff from years of wrenching... so I'd just like to get into a fresher 3g. Still want to sell my 87 white/maroon LX ( body is _perfect_ and all of my parts ( complete 88 carb engine w/ tranny with like 90k miles and some other stuff, including an 86 lxi with 130k actual ( has some rust in the usual places, and the interior needs a good going over ( new carpet for sure)

still hunting for a great 3g..have a couple of leads I'll be checking when I get home. Bad timing on the vacation, but I planned this 6 months ago

happy new year to all of my peeps here..it's been a great 5 years here on 3geez!

[tomsmith]

for daveye, i would get it tuned up first, you know, oil/filter change, air filter, fuel filter, cap/rotor/plugs/wires, timing/idle adjusted. check all the vacuum lines. also take it to autozone and have em run a diagnostic check on it, they should do it for free, and see what codes if any it might be throwing.

[njpeter]

well folks I managed to pass inspection today today..the coil was causing _all_ kinds of problems ( jumping tach, screaming idle..got stuck a couple of times) but I found one I had bought on ebay a few years ago that was in mint shape, and that smoothed the engine right out...the inspector gave me the evil eye and mentioned that the other motor mounts were so marginal that they almost didn't pass them, but heck..I got the new sticker AND I just picked up another 88LX with 200k miles for $900 ( interior mint, and lots of recent work) ( that was my "just in case" car) Looking for a blue armrest now...(got paint?)

on the topic, I took a look at a 2 door LX-i 89 with 103k miles..I took a pass as it needed a radiator ( sludgey) a right axle ( torn boot) and the a/c compressor ( hey don't laugh, I'm an old coot with a long drive) Original owner bopdy and interior were pretty good ( red/beigh)..but an automatic..so maybe not for most of you folks..nice guy..he wanted 1850, I offered 1500 but he passed, now he's reconsidered, but I went with the backup car the same day. Lemme know if you want to see it..it's on Long Island.

now I have to sell that 86 lx-i complete car...no parting out..make me an offer I can live with. 123k actual, auto tranny ( this car starts like a devil, even after sitting for a year in the backyard!, boy I hate to let it go...