Okay so I joined this forum to try to solve a single problem im having.. And i dont seem to be getting anywhere? Idk i thought someone might have some good advise and im sure they do. This is my previous thread that has not been answered and I havent found the problem.




Honda Accord 91' Idle issues?? Can anyone help me with this idle issue?

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So. Ive done a lot of recent repairs myself.. Im 19 years old, and in the machine industry, now learning about my 4 cyclinder 2.2L. New water pump, timing belt, all new belts.. New radiator, radiator hoses, and a few other hoses causing vaccum leaks. So After all this was done i decided to do a few idle adjustments, because my idle was always off. At around 1100-1200rpm. So i decided to first adjust my FIT Valve. I saw a video where a guy tightened the valve clockwise until it was shut. I did this and it cause the rpm to go wayyy down, until i found out that the correct setting is tighten, then loosen 1/8th turn. So i did that. My rpm was still off around 1000, so i tried messing with the idle adjustment screw. I found out it was bottomed out. Okay so i let it be. I had just changed belts, and figured it was okay for now. About a week later, my rpms started getting stuck at 2000RPM. It would settle down when stopped at 1500rpm, but would always go back to 2000rpm when shifting gears, and the clutch was in.. Im now doing steps to clean out FITV IACV and TB, but dows anyone know what else this could be cause from?? Some one give me something!!! Stuck throttle cable? umm idk. I know the FIT only adjusts idle when car is cold. So this couldnt have cause problem?? HELLLPPPP!!
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1. I did all the things and watched all the videos people suggested for this issue. My IDLE ISSUE IS THIS: Car starts up fine. Maybe a little high idle, and around 1000rpm. When I start driving, it goes up to 2000rpm, and goes from 2000 and 1500rpm. When I put in the clutch it drops to only 2000rpm. When the clutch is in it drops sometimes all the way real fast and makes a "farting sound" then always goes back up to 2000rpm. So stuck idle at 2000rpm, and occasionally bog down then up.

2. This is a problem. The car runs great other than this.

3. I did what was suggested and purged coling system to eliminate that, because the cooling system was serviced. Make a great diference in how smooth it runs, but didnt solve problem.

4. I took apart the throttle body, and cleaned in really good, the plate was caked. Didnt effect anything.

5. Lastly I oiled the throttle cable really, good, and adjusted it looser than normal, to be sure this isnt making the throttle get stuck. Everything seems clean and good to go.

6. Also before this i took apart all the valves (IACV, FIT.. and the other america model valve, and cleaned them good. the valves seem to move free, and you can hear them doing their job (I think).
7. IDK what else this could be. Someone help. Not throwing codes.. Id this a sensor issue? Valve issue?

8. Commuter car, need help now??

 

I just recently fixed my idle issue. It turned out that the "intake air resonator control check valve" was backwards causing a fluctuating idle.

 

Did you spray any carb/brake cleaner around the IM area where it mates up to the head in case of a vacuum leak? The idle should drop/change if there's a vac leak.

Also spray it on all of the vacuum hoses.

 

what are the adjustments on the valves for a 1990 honda accord? i have looked everywhere and cant find them.
thanks

 

As already suggested, check for leaks. There is the air boost, maybe this is what you meant by "and the other america model valve" (? not sure), and pcv than can cause the surge as well.

 

Do you know your car well enough to know if the Oxygen Sensor has ever been replaced? My 93 did most of what you described and it turned out to be the o2 Sensor screwing up the air-fuel mixture. No CEL and no code stored in the computer. I think the o2 died so gradually that the computer never noticed it. I replaced the o2 after realizing that there wasn't a miss in the engine, it was more like a choke. My car was also bogging severely. Barely drivable at times. New o2 sensor straightened all of that out.

 

the intake should be .10 and the exhaust should be .12 of an inch

 

Ok first off are you 100% sure you got the timing belt on correctly? And secondly I'm not to sure one your year but on my 94's to set the idle correctly you have to 1: Start your car and let it get to operating temperature. Long enough to allow you fan to kick on. 2: Shut car off and insert a paperclip into your service port. 3: Turn your car back on and now your computer is in a sort of idle learn mode. 4: With no loads on use that same screw to set your idle where it needs set. You can also at this time check and set your ignition timing. 5: Once your target idle is set shut the car off and pull the paperclip out of the service port. 6: Now pull the memory fuse in your fusebox under the hood to reset your ecm. Your idle and timing should now stay where they are suppose to. If everything mechanically seems in order to you it sounds like the idle just needs set properly.

 

yes the air boost, i guess its only on the hondas sent to america. btw... But yes I have used carb cleaner and practically sprayed down the whole engine compartment. Especially where th IM bolts on, and absolute no change in rpm. There had previously been cracked air hoses, but i replaced any i found.. This was before this issue started. But ya It idles at around 2000rpm, and feels like its straining itself pretty good, and when clutch is put in the rpms drop fast and bounce back up to 2000rpm// This is the main symptom. So if theres no vacuum leak, how do i go about this next? start replacing air valves and sensors? At least it appears as if theres no vacuum leak?

 

Okay.. Yea that sounds about right... Hmm well.... can someone brainstorm with me here for a second....
---LIST OF THINGS THAT EFFECT IDLE (DIRECTLY AND INDIRECTLY)---
lol
1. O2 sensor
2. TPS (throttle position sensor) I think this could be the culprit..
3. Air in cooling sys. (CHECK)
4. Vacuum leak (CHECK) or at least i think.
5. ? ??? ????

 

Well to this i say idk about that. If a 1991 idle adjustment is done the same because thats not what it says in the manuel And i dont think the idle being adjusted improperly is the problem. because the car ran great before this occured. So yea, I did a lot of research ann read, and watched before I put on my timing belt. Ebverything was at TDC and the whole thing worked out perfect. Before I did the timing belt, the car idled at around 1150rpm when warm. It was already off to begin with ( THis is an entirely different issue. ) So after timing belt replacement it idled again at 1150rpm or so. I know at least the replacement was done right. Then the rpm started getting stuck at 2000rpm, so something else occured for this to happen.. Am i right?

 

tl;dr. good luck tho

 

def tps sensor behind intke manifold if u havent tried it and its kinda pricey lol

 

The TPS is cheap, but tricky to replace by itself. Replacing it by replacing the whole throttle body is what gets pricey. Honda riveted that thing onto the throttle body because it's a precision device that is designed to last the life of the car and never be turned or adjusted. In truth they rarely fail, but are getting to be like the Main Relay and are being replaced a lot more often than they do fail. When my O2 sensor was failing and I didn't know what was wrong, convinced it was the culprit, I probed my TPS, but it was right in spec.

Fairly easy test. Can be done with the car completely off. If multimeter doesn't have alligator clips, it's best to have a helper touch the probes while you open the throttle and watch the ohm flow. I didn't have help and no alligator clips so I used some T-bar pins from the office supply store to backprobe the TPS and then rigged the multimeter pins to the tops of the t-bar pins. I was able to lay the multimeter in the windshield and feather the gas pedal while watching the voltage changes. After 17 years and almost 190,000 miles, mine was still dead on spec.

If the car bogging and just refusing to go sometimes as you start up through the rpms, then the O2 sensor should be #1 suspect. With mine, I also noticed when I turned the engine off it wouldn't come to a dead stop like it was supposed to; it always had a little final chug even after the ignition was off. That was the intake telling me it didn't like what it was being forced to try to burn. I just didn't recognize the symptoms and was waiting for a CEL to clue me in. It never came. Fed up, I purchased the new Denso O2 for about $60 at Advance Auto and dropped by a little no-name muffler shop and they installed it for me for 20 bucks. I reset the idle (I had been fooling with the air screw) right there on their parking lot and my Accord has run perfectly since.