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Discussion Starter #1
Having problem and can't find out whats wrong. Car starts fine but then after driving for about 20 mins it goes up to that rpm and won't come down till i shut it down and the motor cools down. Like around 1500 to 1800 rpm. I drive a 1990 2dr sentra auto 1.6. Please help, no one can find out whats going on. I looked at the sticky throttle post, sounds like it might work but why does it not do it all the time. Seems like i have the only car that every did this cause no one can seem to find out what the hell is going on. Replaced O2, computer under seat, and had 3 or 4 other mechs look at it, can't put any more money into it because my wife is going crazy that i am spending 2x what the car cost to not fix it and get it right. Tranny went last week and he told me to get the idle fixed or its a rebuilt next time(ouch) wife will flip if that happens, so please can some one figure this out for me and save my ass.
 

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have you check the idle valve just behind the tbi unit ?? might be sticked open ??
 

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Discussion Starter #3 (Edited)
:)
Crazy-Mart said:
have you check the idle valve just behind the tbi unit ?? might be sticked open ??
Please talk in baby talk, LOL. You have to explain everything to me cause i am CARdisabled. Have no idea what that means.
 

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Discussion Starter #4
wow really thought i'd get more help then this, was it something i said? well thanx anyway guess i'll just get rid of it and by a dodge.
 

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there is a valve that is mounted on the back of tbi (carb thing with injector) unit, under the air filter housing. youll have to take the housing out to access it. Its an electrical valve that is clamped just about at the height of the throttle body plate ... when youll declamp it from there make sure you catch the little oring thats behind.. its made like an 8 ...

then clean the valve, check for voltage continuity and if all seem right put it back on with the oring...

If it doesnt help, theres is always a chance that you changed your computer for an Ecu from an automatic car. You could check the part## on it and call the dealer to get the info on where it came from.. is the car getting to normal temperature when it happens ?? .. since youll have the air filter housing off there, check all connections to sensors for corroded or cutted wires.
 

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Discussion Starter #6
the emc was already changed because we thought that was the problem. and still the idle didn't change, it did for a day, but went right back to it the next. Yesterday it was 60 here and i didn't have a problem, today it was 20 and it went right back into racing mode again. Why does the cold make it run faster????
 

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mjb92761 said:
the emc was already changed because we thought that was the problem. and still the idle didn't change, it did for a day, but went right back to it the next. Yesterday it was 60 here and i didn't have a problem, today it was 20 and it went right back into racing mode again. Why does the cold make it run faster????
almost sounds liek the engine isnt warmed up properly and its trying to do just that.. when this happens (revs up to 1800) is the temp guage where it should be?? or is it still cold?? if you have a temp guage anyways..
 

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this makes me think you got a problem with the temperature sensor on the intake manifold ... probably something like bad connections /corrosion...
 

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Discussion Starter #9
Been through this with the temp too. Even if it's that why in hell would it run at 1800, 2000 RPM. I know that to get to temp the motor runs faster but maybe at 1200 1300 rpm not what i am getting. Plus again the motor doesn't start doing this until it gets warmed up. And when the weather is warm it doesn't do it. Should i just put her down or is there a fix fo this?
 

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mine idling at 2000 rpm clutch pressed on cold start... and wont go down till engine is warmed completely... like over the 1/4 on the guage... you changed the thermostats lately ?? did you used a 180degree unit ?? or lower temp one ?? ... i founded out myself that a 165degree unit wasnt getting my car up to temps (barely heating at all) and i ended up changing it after a few months (winter is freezing around here) the car wasnt idling right and was like you discribed also... like the car is going back into the "warming" stage once in a while...
 

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Discussion Starter #11
haven't changed that yet but i am guessing that's going to be the next move. I'll let you know, where would i get on and can i do it myself? oh yea i forgot to tell you that when i am going down the road without my foot on the gas i can do 35 when the RPMs get going. I have to ride with my foot on the brake going through side streets. Or drive in low.
 

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Discussion Starter #12
Would the thermostats have anything to do with what i think is the car heat not heating very well. It keeps me from freezing but i still have cold feet sometimes and it never gets to the point of me taking my coat off. I once drove 2 hours with the heat on high and it never really got hot in the car.
 

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yeah sounds like a crapped up thermostat.... mine was stuck open, and in winter time my temperature gauge wouldnt even register (until i put cardboard infront of the rad, and infront of the grill ). Now with a new thermostat i dont need the cardboard at all.. 5 mins of warm up and its good to go :) easy to replace as well.
 

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Discussion Starter #14
Heres the latest, Had a ton of snow this week end so i went out to shovel. I thought about just starting the sentra and letting it run and thaw out while i did that. Hasn't been thawed in a while. Worried about blowing the motor if it ran at 2000 RPM for that long but said, the hell with it if it goes it goes. Well let it idle and after about 30 minutes it went down to where it should be, i wanted to beat the hell out of it. I got in and drove around for about 45 mins and it never went back to 2000 RPMs. Now please tell me what the F%ck is that???
 

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lots o snow, somethins frozin my guess, my sisters engine back was PACKED with snow, drifts over under, and in every crack
 

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mine idles high and sticks ( 3000rpm sometimes ) when its cold outside... figured out that the throttle cable was sticking.. now that the weather has warmed up a little bit it doesnt do it anymore
 
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