1993 Accord Acceleration Not Smooth

[Draco959]

I have a '93 Accord LX with approx. 125K miles. The acceleration on it is not smooth (5speed). The best way I can describe it is like bumpy or chugging. It's not real bad just noticeable enough to be annoying. The tires are infalted to the proper specs 29psi all around, new spark plugs, new air filter. Fuel injector cleaner was added and still no difference was made. The steering wheel doesn't shake or shimmy so I don't believe it's an alignment problem. Any ideas of what it could be or has anyone experienced this problem?

Also, not sure if it's a related problem or not, but after the car if warm and the idle settles down do around 700-800 RPMs, it tends to idle rough, I would also like to fix this and smooth it out as well.

Thanks for the help!

[92lx]

get your wheels balanced. If that doesn't work.....try running 93 octane for a tank - if it stops then, you're detonating for some reason (timing setting?) and you need to look into that.

Also, do tune up, my buddy bought an SUV that was acting like that, and after we did a tune up it ran perfectly (cap and rotor, spark plugs and wires).

- Nathan

[Draco959]

Thanks for the advice, the tires on it are brand new, maybe 1000 miles on them, so the wheels could be out of balance already? I already put new spark plugs in, so I will try adding in some new plug wires, cap and rotor. I could try runnning 93 octane to see if that fixes the problem. There is no pinging or any funny noises when accelerating though.

[Huffa]

"Also, not sure if it's a related problem or not, but after the car if warm and the idle settles down do around 700-800 RPMs, it tends to idle rough, I would also like to fix this and smooth it out as well."

Check the front motor mount (torque rod) by radiator. The rubber (at top) in them deteriorates and cracks letting the engine vibrate more at idle. There is a flimsy rubber washer on both sides...... simply pry away with screw driver and inspect rubber in mount with good light. You can see if it's cracked or dry rotted.

I just did mine & it made a nice improvement!

They cost about 60 -70 dollars. I got mine off ebay for 47 + shipping.

[Draco959]

Just an update to this problem, which by the way still isn't solved. New cap, rotor, spark plugs, spark plug wires, PCV valve. Fuel filter is next on my list to change.

Regarding the idle, it's where it needs to be I believe, around 700-800rpm after it's been idleing awhile. There is still a lot of vibration though. I popped the hood and rev'd the engine and didn't notice a lot of movement, a little, but not a whole bunch. I assume a little movement is normal?

[Igovert500]

If your plugs and wires and cap are good, then you might also want to check for vaccum leaks and have your 02 sensors tested, either could cause rough idling and improper acceleration

[Draco959]

How would I go about checking for vacuum leaks and checking the O2 sensor out? Is this something you need special equipment to do or am I better off having the dealer do it? I'd rather do it myself if I could to save some $$$. Thanks.

[Igovert500]

Well vacuum leaks are usually pretty easy...turn the car on, while it idles, pop the hood, and listen for any air escaping...like a hissing noise. You can also just look for any cracked or worn rubber vacuum hoses...you can put soapy water on all rubber hoses and their connections and when the car idles, if you have a leak, it would produce bubbles...all of these are rather elementary ways of finding vacuum leaks..but they can work...

An intake pressure tester would be more efficient, but you would either need to buy one, or build one from misc. stuff at home depot.

Oxygen sensors are a bit more difficult, in my mind. Others may disagree. I have no direct experience checking them, so I will just post a few websites that may help you. (note, these pages specifically are about o2 sensors on a mitsubishi 3000gt, but they still have lots of helpful info)

http://www.mr2.com/TEXT/O2_Sensor.html

http://www.shotimes.com/SHO3badO2sensor.html

[Ehscrewdude]

About the idle shaking - My car used to do that, then i had some belts replaced and they re-tuned my idle speed. I idle at around 500 rpm, can't even feel the motor at all.... that might be it.

[dirtdart79]

It could be a worn clutch slipin'

[rodneys]

Originally Posted by dirtdart79

It could be a worn clutch slipin'

You could also check and clean the Port Holes in the intake.They will get clogged with carbon and make it hessitate when accelerating.

[Draco959]

Originally Posted by rodneys

You could also check and clean the Port Holes in the intake.They will get clogged with carbon and make it hessitate when accelerating.

I tried that also, I pulled the intake boot off and sprayed half a can of intake cleaner in there working the butterfly back and forth. I then started the car and sprayed the rest of the can in there working the butterfly back and forth. I haven't noticed any difference after I did that.

[JimmyzGarage]

Originally Posted by Draco959

I tried that also, I pulled the intake boot off and sprayed half a can of intake cleaner in there working the butterfly back and forth. I then started the car and sprayed the rest of the can in there working the butterfly back and forth. I haven't noticed any difference after I did that.

Well, my 91 was running like crap (rough idle and rough accell), and I changed the plugs, cap and rotor...problem still existed, replaced the O2 sensor, problem still existed. Had a mechanic service the IAC valve (carboned up) and he changed the timing belt, water pump, and belts. While he had my car, he also cleaned out the egr ports. Well, I gotta say it was working great and the idle and accell was just like brand new, but then the problem showed up again, I went ahead and changed the plug wires, cuz I remembered the one of the boots came apart when I was changing plugs and that was what fixed my problem, but I believe cleaning out the EGR ports helped a lot with idle and accell, along with changing the PCV valve which was making the engine seem like it had a vacuum leak.

[Draco959]

Just to update the situation, I had the fuel filter replaced and the acceleration seems to have been fixed now. The weather here is is kinda crappy, rain/wind so it's a little hard to tell but it feels better to me.

The idle is still rough when the car is warmed up. It's where it needs to be ~500-700 rpms. I believe the motor mounts are ok. I don't see a lot of movement of the engine when I rev it up. It vibrates the steering wheel and the whole car when it idles. I can see the steering wheel moving.

I read some past posts and the idea that the balancer belt could be off a little and this could be my problem. I'm the 2nd owner of this car and bought it with 125K miles, so I am assuming that the previous owner had the timing belt, etc done. The car is a 5 speed and it idles rough when it it's neutral and also when the clutch is depressed and I'm in 1st gear at a light and I am waiting to go.

Any other help would be appreciated, thanks!