ok i did search for this and i couldnt find anything. But heres basically whats happening, its starts up just fine and idles at about 1,200 rpms when cold, i let it sit to warm up today like i always do and the idle never went down, so i drove to work and on the way there everytime i would shift when i pressed the clutch in the rpms would shoot all the way up to between 3-4k rpms. It pretty much did this the whole time on the way to work, very annoying when slowing down for stop lights but ill live.

So i got to work shut it down, went about my day, i come back out from work and the car wont start it cranks but no start, so i have this kid i work with give me a jump, because i figured it was a dead battery, so he gave me a jump, couldnt really get it started, i finally got it started by giving it some gas, and it idled really rough for like a few minutes, then it went back up to 1,200 rpms and i started to drive to auto zone to get another battery, on the way there it did the same thing it was doing this morning, i went ahead and bought a battery anyways as i figured it hadnt been replaced since i got the car in like 00 so it was about time anyways.

I also noticed that in 1st and 2nd gear if i put it in and slowly let the clutch out without hitting the gas it would act as if i was giving it gas. Kinda weird, also when i would get off the gas still in gear then get back on itd sputter.

I dunno what this could be i figured vaccuum leak but none of the symptoms seem right for that, except for the hard start. It could be a vaccuum leak based on the rpm jumps but for them to jump that high id figure it would be a big leak and id be able to hear it and i was underneath that hood for like an hour and heard nothing.

I dunno if someone can throw me a bone on this on id appreciate it, didnt have any more time to troubleshoot it tonight, so figured id post up on here and see if anyones got good responses for me tomorrow after work.

Thanks for the help in advanced, and sorry about the long post, but i feel it will help diagnose it as everything that has happened is in there.

I'm going to say your TPS sensor is going bad and it keeps opening the throttle since it thinks it is closed completely. Just a guess though.

I'd suspect TPS as well. Perhaps IAC, given the hanging idle.

Aren't the 95s known for some ECU issues? You ever have the ECU flashed or whatever? Anyone care to offer more insight into the 95 ECU issues...

no ive never had the ecu flashed, also the problem just started. so i guess ill just replace the tps sensor since i dont have the tools required to test it.

I found this same issue when I scanned Eric Metcalf's 2GNT. The TPS would short out and tell the ECU the throttle plates were open. The Euc would add fuel and cause the idle to raise and surge a bit. See if Autozones scanner will give you a voltage readout on the TPS to see if the value is stable of if it fluctuates without you touching the gas.

If it does, get a new sensor.

Terry

i replaced the tps with a new on from autozone, stillhaving th same problem. do i have to reset the ecu by taking the neg cable off and hitting the brake to reset it?

if not, im outta ideas, any input would be appreciated. thanks all

well today im getting me my hands on a multimeter, its not the best one but itll do the job.

so no more throwing parts, im gonna test everything that has to do with my problem.

if you think im missing anything let me know, already replaced tps, debating on whether i should return it. when i go back to autozone ill have to get another throttle body gasket, as i took it off to get the tps off, the old one looked fine so i just tightened it back up, but i might as well replace it since ill be taking it off again for the iac testing.

1. iac
2. upstream 02 sensor, as im sure down stream wouldnt cause this.
3. egr
4. map sensor

I had a problem similar to this for quite some time in my 95 eclipse, the car would idle low every now an then and seem like it was going to die unless I gave it gas. Or it would shoot up in rmp for no reason. After trouble shooting many things I replaced the computer and that fixed all problems. Of course this is expensive, I had mine sent in and rebuilt for quite less, I dont know how old yours is but I've heard this problem before before and it sounds like the same thing.

well if it is the pcm or ecu, the car is going bye bye, its not worth the cost and time to replace the pcm or ecu. if i wouldnt have gotten into the accident last year it might of been, but with the accident happening, the strut tower rust etc, its not worth like a 500 dollar repair. i would soon save that 500 dollars and drive the car as is till i get enough to get another car or lease a new car.

I don't know if you've fixed your problem but mine was doing the same thing. Would idle rough around 1500 then jump to 4K and stay there.

I replaced MAP and IAC with no luck. With the intake off i could plug the hole that feeds the IAC and it would idle fine. So i ripped off the IAC and plugged the hole with some rubber stoppers and a backing plate.

The car idles fine now but it still hasn't fixed the problem. I noticed that with the IAC off the throttle body it would extend like it's supposed to but when it's installed it seems like it's opening all the way. I'm gonna try and figure out if the wiring is bad, but that's all I can think of.

If you wanna see the stoppers i'll take a pic.

i think you have a different problem then me, technically my car idles fine, its right at 1200 where its supposed to be when its cold, it never drops from 1200, but when driving and i go to switch gears the car will rev up on its own. and when going to a stop it does the same thing and the rpms will not drop untill the vehicle comes to a complete stop, or i put it into a different gear.

hey so does anyone know how to test the map sensor?

its a good day out here today and im gonna test a bunch of things that could have to do with this.

If everythings good ill check the map sensor.

its not throwing a CEL so i dont know how it could be the map sensor but ill test it.

man does mitsubishi make things hard to test.

OK heres my question guys i tested stuff, the ECT sensor was fine, The IAT was readin under the standard value, im gonna take off the throttle body and test the IAC soon.

But i was just wondering since the IAT is reading below the standard value, can the Intake air tempature sensor actually cause the problem i have described?

Off to take off the throttle body, ill probbaly have to get another gasket for it now.

check your alternator,

our cars will increase idle rpm if the battery is not charging correctly or the alternator is about to die.

Lates
James

found the problem and created another problem hooray for me.

but yeah i replace the iat as it was bad, noticed the throttle body vacuum hose was leaking so i bought a new one from the autozone. the guy said the hose was two different sizes one for each side, so i got the smaller size, i got the hose on the vacuum line after a lot of damn pushing i also clamped it down to negate it blowing off.

question comes with this: when i was doing so theres this little plastic vacuum hose that i cracked and 9its a delaer part or steal from another car only. it goes from the egr solenoid connection all the way to the intake mani. the car seemed to run fine without it.

SO Am i safe to run the car till tuesday when ill be able to get this vacuum line?

id say the hole created by the crack is about 1/4" at most.



lol apparantly the f word changes to ban me.

hmmm, i have a month running without that vacuum hose.. should be ok

thats cool i replace it with a soft silicon one anyways, it seems like it was hard plastic before, but it seems to be working. also the idle problem isnt as sever, but its still there a little bit, so ill just drive it for now, and next wknd try and see if i can find another vacuum leak.

o man i love my car so much, still same problem tested everything but the 02 sensors. ill look for the vaccum leak again this wknd, and hope i find it, if not im just gonna drive it till it blows up, and get a new car.

Thanks for the help guys