high idle

[vansolrick]

Intersting. I have idle problems after I reset my TPS. However. I know I have the TPS set correctly. I tuned it with a ohmmeter and it is in the correct range. My butterfly valve screw is all the way down. When I start the car with the IAC disconnected. the car stalls so I know its cut off all the way so the only air getting in (or so I should think) would be thru the IAC when it's connected.

Once I connect it, it goes up and idles around 900-1k. Sometimes it will go down to normal (750-800) for a second or two, then slowly raise back up to 900-1k. It's annoying. I cleaned my IAC a while back and the TB is clean, ported, and polished.

So, im pretty lost. Sometimes when I start the engine in Diag mode with the IAC disconnected, but have the butterfly valve screw open 1-1/4 turns, it will idle and almost die at 200, then raise itself to about 400. Somewhere air is getting in. I'm really confused. Vacuum leak?

[mikeetown]

mine had that when i got it. Maybe your rocker cover gaskets are leaking and vacume is being lost from there. That was my issue. I also cleaned a lot of sludge buildup in the pcv piping under the rocker cover. The large vacume lines were sludged too. You probably have a sludge problem. THat hoestly, made mine idle at 600 rpm. And its perfect now.

[mikeetown]

lol update

There are some hoses that go from the rocker covers and connect to just before the throttle body. Basically, hot air runs through those hoses and is ran throgh the throttle body which at warm temps smooth out idle. (my mechanic is 61 from ukraine and has worked for various company's there since he was 19)

He told me this. I told him that those lines on my car were full of oil when i tore the top end to do my valve seals. He told me that i'm missing some filter that should be in a certain place before the hot air leaves the rocker cover. We solved this problem by installing PCV valves on the front and rear hoses so oil wont clog the line. Now, my 265,000 km engine runs smooth at 650 rpm or whatever. It runs smooth anyway. But if you get slight rpm bumps it just means my engine is old and worn.

I hope ppl understand what i said. I'm in class and just had to write this cause BIOlogy is boring.

[mitmaks]

rocker cover, you mean valve cover...If so I presume you were missing PCV valve. Yes, PCV valve is supposed to keep oil out of line (vacuum line) but doesn't always work.

[cudgel]

We noticed that the idle only drops and surges when the gear shifter is placed in a gear. If you place the car in neutral the idle levels out and remains constant. We unplugged the neutral safety switch and placed a jumper wire across the computer side (female) electrical connector making it a constantly closed circuit. This made the idle remain level regardless of whether the gear shifter is in or out of gear. Although the jumper wire is sufficient to fix this problem, you need to look further into whether the neutral safety switch or ECM is malfunctioning.

*****When you are starting the vehicle with it in gear it COULD move when your foot is not depressing the clutch******

[davmac]

From personal experience idle on these engines is very sensitive to the coolant temp sensor output. If coolant is low or you have a leak the sensor is not always covered in coolant - sends out variable signal and causes surging idle or if always reading cold a high idle. Focus on coolant level and finding leaks because the sensor is rarely the problem.
Many IACs also do not work. My bad IAC would not provide high idle when engine was cold – I had to do that with my foot on the gas or the engine would die until it was warmed up. It took 3 salvage yard IACs before I found one that worked.
Finally adjust your TPS using an ohmmeter and feeler gauge. The procedure is found in the service manual starting at this page. Or search TPS adjust - many people have posted on this topic.

[mikeetown]

http://www.uk-mx3.com/forum/viewtopic.p ... bd87d2cd0f" onclick="window.open(this.href);return false;

everyone should read this, then post a comment. I am going to try this. I've done everything except adjust the stupid TPS sensore his way. My K8-ZE has about 60,000 km on it and i've redone all the vaccume lines, gaskets, valve seals and etc...... so i think its gonna be this article or a coolant temp sensor.

[mikeetown]

well it totally worked. I put the car in mid timing mode (jumped ten + grnd in the diagnosis slot), then i adjusted the idle (the idle screw on the throttle body) 2 about 700-800 rpm, then i adjusted the TPS and tightened it to just before the fan turned on and its awesome.

[m7x3r]

Hey guys, I am hoping I can ask this question related to TB and the gunk in it and respects to the nice procedure made ... even though i didn't go this hardcore on cleaning my TB as described one time i noticed the start of the carbon build up... so i got one of those spray bottles throttle body cleaner or carb medic or watever so i followed their instruction first on a KLZE so much high compression when you take your intake piece and MAF right to the TB car will shut off so I had someone help me start it spray and chock on the butterfly... butterfly sometimes gets stuck like a lock mechanisim that i never understood my old K8 didn't do that but this one KL47 if you hit a certain RPM it will lock anyways ... chocking away at the car while spraying and wiping the inside of the TB clean around the butterfly flap spraying for less than 40 secs all together... then shut off the car for about 5 10 mins ... checked TB looked cleaner than before only few spots missed.. replaced the intake tube and all started the car ... car was already warm but was revving at 1500 RPM ... continued to rev high today it's down to 1200 or 1100 sometimes just at 1 but still when driving and popping it into neutral from say 3rd it will rev high i have also at the same time did a stop leak on my rad which affected engine temp and heater temp i had a small leak in the rad so i tried this stop leak but introduced some heat exchange problems... heater doesn't become really effective till after car is being driven not like before... thought i would mention this in case the vac system and rad. system or temp are somehow interconnected or readings at the ECU reflect each other....

thank you in advance sorry for the lengthy question...oh one last note my idle screw is almost tight all the way down... i usually adjust the screw without any jumper wires ... thanks

[newdriver92]

i got the same issue but the idle is random and at same times as u

[m7x3r]

I ended up finding a vac. hose that was loose the nose needle where the vacume hose plugs into was broken it's made out of plastic because it goes to a sensor that has the mitsubishi sign right next to the runners on the right of them next to the the MAF it's a sensor outside mounted to the engine on its own... you can use water or brake cleaner or throttle body cleaner spray spray around the vacume hoses around your car there quite a few on the v6 engine while the car is on obviously... see if you can find a hose if you're sure there is no vacume leak... what I think fixed my problem is doing the timing properly ... i used to adjust the idle screw without jumping any pins... but apparently the proper way like indicated on the few threads i found was to jump the TEN and GND pins in your diagnostic box next to the firewall right above the brake booster if you open the cover it has a map of all the pins and their names use any of the two GND pins jump it with a wire to the TEN pin start the car let it warm up... when it's nice and warm where it should be at idle temp. adjust the screw till your idle speed is bout 650-800 somewhere there should be good these engines naturally run rough i noticed specially if you take out your cat and have an exhaust and so on .. try to clean your TB before you do this if there is alot of gunk ... but I can bet my money you got a vacume leak somewhere because it fluctuates ... spray around look for idel speed change when u hit a nerve or a leak... that's how you know sometimes the hose is fine but could be valve in the line that's bad like the one on your brake booster that's a big one if the valve is bad air doesn't flow properly valves are suppose to allow air to flow in only one direction ... i had fun fixing the brake booster vac problem that caused my brakes to seize or jam up even a small tiny little hole is enough to do the damage ... hope this helps

[newdriver92]

i took some quick start and sprayed it in some spots