89 Escort high idle, need help!

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Hey guys, this is my first post here, i have been looking all over for info on this problem, hoping you guys can help out! :D

Alright i have a 89 escort, it's a stick and i did all the tune up stuff when i bought the car (2 months ago, about) it looks to have a new timing belt and its got a new fuel pump (dunno if that stuff matters) Anyways, when i start the car it immediately goes to 3k rpm, and steadily climbs to 4k+, I have no clue how to even start checking into this problem, i was told it could be the throttle position sensor but i dont know how to check it, or find it for that matter, i would rather not go buy a sensor just to see if that was the problem, anyone have any ideas for me? It would be greatly appreciated i need this car for school and its a real drag walking everyday... lol plz help!

posted by  Halz5

I'm going to suspect 2 things to start. TPS or Vacuum leak.

posted by  DodgeRida67

My initial thought was a vacuum leak, although 3,000-4,000rpm is very high, even for a vacuum leak :ohcrap:

posted by  Cliffy

4,000 is kinda high for a vacuum leak, 3,000 is also a little high. Although, I've seen some unbelievable things happens with cars. Always saves time to check the simple things first. Usually when a vacuum leak makes an engine rev close to those numbers it goes in the other direction and runs very badly. Who knows, could be a vacuum leak. But what I said before, vacuum leak or TPS is what im thinking. :smoke:

posted by  DodgeRida67

pull the codes and report back. Let us know if you need help pulling the codes

posted by  tbaxleyjr

http://www1.autozone.com/servlet/UiBroker?ForwardPage=az/cds/en_us/0900823d /80/11/f0/8f/0900823d8011f08f.jsp

provides instructions of testing the tps

posted by  tbaxleyjr

Thx for the help guys, either tomorrow during my lunch break or after school i will try the test on the throttle sensor and report back to you guys, thx again i really appreciate it!

posted by  Halz5

no sweat

by the way - dodgerida is right about vacume leaks - most of the time, a vacume leak will manifest itself in rough idling, poor acceleration, ignition system misfire (mixture too lean for spark to ignite) and other nasty things such as that.

Fast idle is normally associated with the throttle controls/feedback or the idle air control/bypass system

posted by  tbaxleyjr

Alright, it's lunch time and i tried it, lol i realized i dont really know what i am doing so i will tell ya'll what i did and the results and you let me know. I took the voltmeter and "back probed" the connections negative on the black negative wire and the positive on the red wire, with the key on i got 5.86 volts, then we slowly gave it gas, till it was at WOT and nothing changed, just for kicks (didnt know why) i tried starting it but it wouldn't crank, dead battery, something is either draining the battery or the battery is bad, but it doesn't look old, did i test it right? anyone have any further suggestions? thx for the help so far guys!

posted by  Halz5

Hey guys, ok this is what i got now,the red wire i tested before was the reference voltage? so the green wire is the one i wanna check.


So volt meter is grounded to the black wire on the TP sensor and the red lead is on green wire, key on i get 1.12 volts it steadily climbs as the throttle is pressed and at WOT i got 5.06 volts, i heard somewhere about tapping it and seeing if it would jump around, well i tapped on it with a screwdriver handle and nothing happened, so that means the TP sensor is good right?

Also with the battery, it was at 10.6 volts at noon, then at 3 i had 9.5 volts, i dunno whats going on their but i rather concentrate on my other problem first lol.

Also how do you pull codes on a Ford? I know Gm you jump the A/B and count the blinks but ford....i dunno, Thx again guys

posted by  Halz5

Odds are good the TPS is OK

I would find the electrical short which is draining the battery since diagnostic testing requires the car to be @ full voltage

http://www1.autozone.com/servlet/UiBroker?ForwardPage=az/cds/en_us/0900823d /80/11/f0/d1/0900823d8011f0d1.jsp

http://www1.autozone.com/servlet/UiBroker?ForwardPage=az/cds/en_us/0900823d /80/11/f0/fb/0900823d8011f0fb.jsp

are hook ups for retrieving codes on a Ford. Check the underhood emmissions label to determine if you have EEC-IV or MCU although I think the hook-up is the same.

posted by  tbaxleyjr

Hey, i didnt really get the links you gave me but what i tried it taking a battery off a car that i know is good, and i will see if it loses the voltage or not, maybe the battery wont hold a charge.


Also i tried doing the self test thing with a VOM and i hooked the negative probe to the 4 pin and connected the positive probe to the + side of the battery. then i jumped the no. 2 pin to the self tester thing and turned the ignition on and the numbers just jumped alllllll over the place, i dont know which ones mean codes?? which ones do i want? or what do the other numbers mean? also if anyone can, to make it easier, im me (aol) Halz5 or (yahoo) godsmackguy6662003. thx guy

posted by  Halz5

Alright i just looked at the links again and i understand the second time around, i still dont really get the VOM test but i did the blinking light test, and i did it twice getting the same results so tell me what you guys think, i got a 12 and 13

which autozone says are....


12 Idle Speed Control (isc) - failed at elevated rpm
13 Idle Speed Control (isc) - Failed at idle rpm


So does that mean, the idle speed control is bad? if so where it is and how do i test it or fix it? thx guys, you dont know how much i appreciate everyones help

posted by  Halz5

LOL alright, well its the Idle speed control, i took it off and the car ran fine idled good and everything, i cleaned the contacts and put it back together and it actually worked with it too, then an hour later i started it back up and it wasn't working again, i am not sure if its the part going bad or if it is the contacts, right now it is off and it runs fine, so do i really need this part its 80 bucks so if i dont really need it i dont wanna spend 80 bucks on a 200 dollar car.



Also the battery problem, the battery was just shot, got a new one and i am good to go

posted by  Halz5

That means we need to test the Idle Speed Control system. If this escort is a 1.9 L, it probably has a form of throttle body fuel injection. If this is the case, there is an Idle Speed Control actuator which cracks open the throttle plate in response to a signal from the ECM and regulates the idle speed. Since your car has an EEC-IV computer system, the below site will show you how to test the IAC actuator.

http://www.autozone.com/servlet/UiBroker?ForwardPage=az/cds/en_us/0900823d/ 80/11/f0/43/0900823d8011f043.jsp

I am linking you to another page on the autozone site. the reason I do is the iinfo also has pictures which makes explaining procedures easier for me.

I am suspecting a bad ISC actuator

posted by  tbaxleyjr

Thanks, i'll try that tomorrow after school, i dont have the tool to measure it, would a tape measurer be good enough? i hope so, also how do you find this stuff on autozone? i never knew they had all this info on their i search for like a half hour to find how to test that stupid idle speed sensor, it kept saying part doesn't exist or sent me to the price page, btw i am not paying that lol

posted by  Halz5

under repair information.

posted by  tbaxleyjr

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