ok. My idle suges up and down up and down after the car warms up top op temp. Please help me with this. I need to fix it as soon as possible since they failed me for it in NJ inspection . I tryed a few things and when i pull the sensor off of the throttle body not the MAP sensor, but the other one(not sure what its called but is located toward the rear of the throttle body) the idle smooths out. I should also mension that this only happens after the car has completely warmed up to op temp and it evens out after it goes up down up down up down about 4-5 times untill the next time i hit the throttle. I checked the throttle linkage and all seems to be good there and cleaned the iacv no help there either. I dont think theres an fitv on my car( have checked numerous how to's and mine just doesnt appear to have one on it ). Any ideas with all the info i have provided here would be GREATLY appreciated. And if it fixes the car could be 5 bux in Paypal for it too . Thnx in advance for ne help.

EDIT- its a 1995 honda CX hatchback w/ the dreaded 80 hp 8 valve motor.(foget the number)


Modified by rcjustin at 5:26 PM 2/2/2006

 

If someone thinks they can help me out post or if u have the time to talk thoroughly catch me on aim- mirramaster Thanks

 

Did you check your FITV?

Also, check your idle adjustment screw, if it's too far out it will cause a small vacuum leak.

 

you should have an fitv under your throttle body..but anywayz on the back of you tb there is a plate...it has 2 8mm bolts on it..take that plate off and there is like a plastic screw in there...screw that all the way in..sometimes it comes loose and causes a vacumm leak....

 

I have the 8 valve 80 hp motor if it helps. There really is no plate on the throttle body to take off and if i do have an fitv under the throttlebody it doesnt come off. I took off the whole throttle body today in search of it and nothing. I may be built in tho cuz there are 2 hoses that come out of it 1 in and 1 out. Im so lost with all of this, if somebody can explain a little better for my newbish self please do.

 

Did you replace the throttle body gasket when you took it off? That could be the vacuum leak right there.

 

it was happening before i took it off also so it has to be something else.

 

When it did start to happen? After you cleaned/installed/checked/modified something?

How many miles? When did you do a tune-up last?

 

I dont honestly know when it started. I bought the car 2 weeks ago and it was doing it since day 1 so idk when it started for him. He said adjusting the idle speed would work but it didnt. Car has 93000 miles on it engine and chassis. Also dont know when last tune up was done to it but i have so far done an oil change, coolant change, and MT fluid. What does it mean when i pull that sensor out though and everything works correctly? Does that mean that its just a bad sensor? As soon as i pull that sensor out (TPS?) it stops the idle surging.

 

The sensor is fine. You either have a vacuum leak or a mis-adjusted base idle.

 

Is there any way i can rewire(jump) the sensor so it doesnt show a CEL on my dash and still stops the surging idle problem? Have ne ideas which wires to connect to do this just until i pass inspection?

 

people already said fitv and iacv....check and see if there is an air pocket in your coolant ..may sound stupid, but alot of the newer acuras have this problem...good luck

 

Clear your codes and see if the CEL reappears. If it does read the code and post. The problem goes away when you unplug the TPS because the ECU goes to default. Same reason why it only happens when the engine is warm. Any excess air that enters the motor can cause this idle surge. Vacuum leaks, IACV, FITV, EGR not seating when closed, bad PCV, throttle cable too tight, and idle screw out too far can all cause a high idle. When the idle exceeds ~1200-1400 RPM with the engine warm and the throttle plate is closed, the ECU cuts off the fuel injectors. The idle falls below the threshhold, the injectors cut back on and the whole cycle starts over again. I had a starting boost valve(accord) that was leaking through the diapham that caused mine. Something like that can only be found with a vacuum pump/guage. Anything that has a vacuum line running to it can cause this problem if it won't hold vacuum, not just the vacuum lines and gaskets. This includes EGR diaphram, Boost valve diaphram, cruise control, MAP, Intake bypass valves, Purge solinoids and others. You need to set the idle to between 450 and 550 with the IACV unplugged. Plug it back in and clear your codes.

 

i dont have a cel anymore just when i unplug the tps but i am going to borrow a vacuum pump from my autoshop in school and see if i can locate a leak. But if i cannot get this fixed by monday is there anyway to bypass that TPS sensor to make the engine not idle unevenly just untill i pass inspection?

 

There is a paticular ohm resistor that you could plug into the ETC connector that would keep you in default like when the engine is cold, but it also runs a richer mixture in default. You would have to do a search to find out the correct ohm resistor and get one from radio shack. I can't think of anything else that wouldn't set a CEL. Somebody markets this as a "10 HP increase" or something like that on Ebay.

 

I searched thru ebay with no luck, Think you can post up the link for it. Searched ht too and also no luck. LMK if u still have the link for ebay or HT.

 

anyone know what OHM resistor is needed to do this?

 

Did you ever bother to check what your base idle was set at?

If you try and use a resistor as the ECT sensor, you'll probably get a code too. If the ECU never sees a change in the ECT, it'll think something is up.

 

Ya, i tired adjusting far enough in to where it wanted to stall and far enough out to where it was way too fast. I guess ill just try the vacuum pump to find a leak.

 

I don't think there is a time limit for the ECU to 'see' the ECT change, but I also would reccomend that he just find the air leak and not try to fool the computer. I'm sure the ohm range for the ECT is in the manual.

 

Once again I want to preface this by saying that I think you should find the vacuum leak, but I looked up the Temp sensor resistance and if your going to try it, use between a 2200 and 2700 ohm resistor. A 2 watt should be fine maybe even a 1 watt. It's probably 25 cents.

 

~300ohms is 180*F to the ECU. You can use a 1/4W resistor if you're so intent on trying it.

I'd suggest you find the leak instead.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by EE_Chris &raquo;</TD></TR><TR><TD CLASS="quote">~300ohms is 180*F to the ECU. You can use a 1/4W resistor if you're so intent on trying it.

I'd suggest you find the leak instead.</TD></TR></TABLE>Remember though, he's trying to make the ECU think the motor is still cold so it will stay in default. 180F would be warmed up.

 

Well, i AM going to TRY as hard as i can to find this leak but if i cant then ill get the restors. I have until monday to get it w/ no CEL and no surging idle. If i do have to do this jump, where does it go? Connect directly to the tps sensor? Where should i put it? Possible pic if oyu have the time if not then just where would it jump?

 

No. It goes in the connector for the ECT or engine coolant temperature sensor. Get the TPS out of your head. The only reason unplugging it helps is because it puts the ECU in default. The TPS is not the cause or salvation for your problem. Keep in mind if you do this that it will make the car run rich and you may fail on hydrocarbons or CO. I would wait until I was down the block from the testing station before sticking the resistor in the connector.