we have a '85 honda prelude with a rough idle in drive, would welcome any ideas?

Question

our prelude is a good car, a daily driver everything works on it (except the car stereo, another subject) but it idles rough, i changed the o2 sensor but i still get "efi" light on the dash, and when i put the car in drive, the idle gets real rough and i smell burning coming from around the catalytic converter, other than that, the car is ok,

we welcome any and all solutions and ideas

Answer 1

I have found it allways pays to spend the $45.00 to have it dianoised than to go chasing after the problem with parts buying on my own. I have the print it out and piont to what is bad , go buy it and change the compoent myself.After i replace the part. i disconnect the battery pos+ for 5 min, then reconnect it to reset the computer. Having said all that , straight up it sound like your cat is plugging up. They Make this magic potion that you add to your fuel to clean them up, however i think it is snake oil. I just change them out. Rough idle can be caused from many things.Here are a few. Vaccumn leak.( spray all connections with wd40, if rpms pick up you have found a leak) Loose carb, fuel filter, Timing, Choke out of adjustment or stuck on.weak fuel pump, fouled plugs,tc It sounds to me like you like you car. Have a fun day today

Answer 2

Take it to a "muffler shop" and have the catylitic converter checked. -- It really doesn't sound like this is the problem,since the catylitic converter would restrict acceleration, and higher speeds if it was "plugged up"! There is an "air bleed tube" going into the converter (this makes it "burn" the impiurities better), -- if it is restricted, or plugged, - it will make sensors register wrong information, -- and will eventeually plug the converter up anyway, ----- you need to avoid this as the converter itself is expensive!!.... The "smell"could be as simple as a drip of oil burning on th exhaust pipe as it "heads to the ground"! Since no description of what it smell "is like".

I would check to make sure that it doesn't have any vacuum leaks around the intake maniflold, - or carbureter (air intake on fuel inj. car), -- If you have one, - it will run poorly at idle (or very low speeds), - but run fine when rpms get higher. This is because it is sucking air in "behind" the fuel metering system, and therefore makes the mixture too "lean" which makes the engine run poorly!

I suggest you just "fix" the problem, It is "dumb" to trade it off and buy another one if it is fine otherwise! So don't listen to this kind of talk! You know all the problems and weaknesses of this car by now! If you buy a used car, you can have all the last guys problems to contend with now! And if you buy a new car, - you can have all "new problems", - (Never before expericanced by anyone else!) --------- The only difference is that it has a warranty (which costs you a lot - considering the difference in price from what you have now, - and a "new car price!"

Answer 3

first off if theres burning by the catalytic replace it i have actually caught a toyota on fire because of a malfunctioning catalytic which is also indicative of more severe problem next good work with the o2 good idea but not the major problem have you done regular maintence as in new plugs and wires
you can test current wires pretty easy wait till dark start it take one off and hold in near metal if you see a flash it works test them all next is time it if you dont know what that means get a professional to do it simply because you can get the timing off by just a fraction of a inch and your car wont run next is start checking the tightness and servicibilty of your engine mounts, and transmission mounts and the bell housing takes a long time for any of these to go but with a 85 its very possible that one is loose or broken other than those just general maintence oil air filters also a hi flow air filter could help if the idle is bad your culprit is either no spark ie bad plugs/wires or incorrect timing (and on the timing gig if you cant fix the problem you can at least retard your timing to stop the roughness) low gas flow ie fuel line or filter clogged, dying fuel pump, bad injectors or low air flow which is what you were trying to fix with the new 02 sensor the efi light you mentioned tho would lead me to believe it is the fuel thats the problem either pump or injectors as efi stands for electronic fuel injection off hand i dont know how many injectors a 85 prelude has (4 cylinders so you can bet on at least 8 at about a minimum of 50 dollars per new injector) but different manufacters use different numbers of injectors anyway off the top of my head those are the causes of shaking and rough idle loose mounting, bad spark, bad air, or bad fuel tho on a horrific note it could be bad compression but that would also come with a lot more problems than a rough idle but if you do find that to be a problem trust me dont rebuild dump that car today lol

Answer 4

Trade it in before it quits. Sounds like you have a blown head gasket. The smell is oil leaking out of the head and leaking down to the catalytic converter.

Answer 5

efi, possibly needs "bleeding", also, check the ignition timing.
good luck.
ps....catalytic converter, "can" cause a lot of problems, have it checked.

Answer 6

vacuum leak! your throttle physique is closed at idle. your engine produces vacuum while your cylinders.....ah F*** it...you have a vacuum leak. carry it to a shop it's going to be a miles less costly fix.

Answer 7

THIS IS THE ANSWEAR TO YOUR QUESTION
YOUR PROBLEM IS THE TPS SENSOR
THROTTLE POSITIONING SENSOR
GO TO ANY JUNK YARD AND GET IT
YOU CAN GET IT OFF ANY HONDA THAT HAS THE SAME ENGINE