It is a stock 1990 integra gs, I cleaned out the Iacv it helped a little but still haveing the problem. The engine will idle normal at first start, then after a while it will dip down to about 100-200 rpms then sometimes it will bounce back up, sometimes it will shut off. Any ideas?

 

could be the Main Relay

does it only happen while idling cold? if so, try cleaning/adjusting your FITV

 

It happends even when it is warm.

 

Exactly when does it shut off? Describe it exactly when your driving.

 

When I am driving it only shuts off at a stop light when I am in neutral. If I just idle it in the driveway it will idle normal for a few minutes then it starts to go up and down and then finally it will just go all the way down. I noticed today that the oil light goes on below 1k rpms.

 

Car has a check engine light, it is code 43. I am going to change the o2 sensor. Think that would cause the funny idle and shut off?

 

anyone?

 

try adjusting the idle thing that's on the throttle body. Its right above the T/B and its a gold circle with a slit in it (flat head). Turn ur car on and start playing with it, it should bring more air into the intake mani and make ur rpm go up

 

also check your timing and vacuum lines

 

yes the O2 sensor could be the problem - it helps determine the air/fuel ratio. also, what Stasher1 said: check your timing and vacuum lines. i believe timing should be 16 +/- 2 BTDC

 

+1 for me..I also have this problem..its a 98 gsr..I also cleaned the iacv and adjusted it..the check engine light is also on for the secondary o2 never had a problem with it..the light was on for 3 months never had the bouncing issue..and made adjustment..didn't help the screw is tight..it bounces at 1500rpm...Sorry to jack your thread..

 

Yeah, replace that O2 sensor and reset the ECU. Should fix the problem. I actually had an O2 sensor that went bad after 1 year, turns out I needed to replace the fuel filter (and other minor repairs) which caused it to fail prematurely.

 

Sounds right, the previous owner just changed out the fuel filter because they were having problems, must of burnt out the o2 sensor. Thanks, I will post my results.

 

I have the same problem with my DA! Help me?!?

 

check the resistance of the tps.. you might have to reposition it if its incorrect. also the iavc .... had similar issues and got it to work..

 

Ok, so i changed the o2 sensor, reset the ecu. The check engine light went out, the car idled fairly normal with a slight fluctuation, not bad. Then I took it for a test drive, as soon as I took it out of gear at a stop sign the idle went to zero and shut off. Then I started it back up and it wont idle at all, it just shuts off. It drives normal as long as I am in gear. The ecu is now flashing 43 again. On the rpms way down to zero the oil light comes on. Any ideas?

 

Update, today I drove the car to school and it idled fine. So I imagine that the new problem is only when warm.

 

A few questions:

1. You mentioned the oil light comes on when rpm drops below 1K. Did you mean 100 rpm or really 1000 rpm?
2. Does your car smoke at all?
3. Do your headlights fluctuate as you accelerate?
4. Does your car hesitate at all when it does run?
5. How's the temp on the temp gauge, does it ever overheat or get close to it?

 

New update, I took the Tb off and cleaned it. I put in a different map sensor and the idle went to 2k no more dieing at idle. I put the old map sensor back on with the same effect. So now the car no longer dies, but idles at 2k.

AK77:
1. 1000 and below the light comes on.
2.no
3. no
4. Only on start up.
4. Never over heats, sometimes slow to get up to temp.

Also the car sometimes starts up like a lawn mower, almost winding itself up.

 

Thanks for the update. So when you first start your car, it is supposed to idle at around 2k rpm then slowly go down to 700-800rpm. To bring your car to normal operating temperature, FIAC (Fast Idle Air Control) valve allows more air for combustion and therefore its revs around 2k rpm. As the coolant warms up it shuts off the FICA and allows the IACV (Idle Air control Valve) to control the idle from that point. If the idle is set too high, rpm will jump between 700 and 2000. That can also happen at times because of other reasons.

So when you cleaned your TB you must have cleaned the FIAC as well which was probably clogged and not letting enough air in.

So, more questions:
1. Is your RPM gradually coming down and staying constant at around 750?
2. Have you checked your throttle cable to make sure its not bent or stuck around something?
3. As far as it starting like a lawn mower, have you checked your spark plugs, wires, distributor rotor, cap and the Ignition timing?
4. Have you reset your ECU after cleaning the TB and replacing the MAP sensor? (You can do this by removing the HAZARD Fuse for more than 10 seconds, located at the positive terminal of your battery, one of the many ways to do it...while your car is off).

P.S. IACV can be adjusted if your idle is not set to factory spec, ie 700-800rpm.

 

The Rpm never comes down but i think you are right and it is a throttle cable problem. I will check the dizzy and plugs/wire too. I just unplugged the battery term and the ecu fuse. I will try the hazard as well. Thanks for your help if you come up with anything else let me know. I will update later.

 

im having a similar problem also, but i havent reseted the ecu, what is the proper way of doing this? and also when i try to rev up the engine really fast lets say like if im trying to burn out it doesnt rev up quick, the rpm's drop down to like 800 and slowly start to go up, can some body help me out?

 

I changed the plugs, cleaned the rotor and cap, seems to fix the lawn mower problem. I reset the ecu with the hazard fuse. Now it is reving at idle between 1500 and 2000. The idle never goes back down to 800 after warm up like my R does.

 

Have you reconnected your IACV behind the Intake manifold?

 

Yes.