1994 high idle problem
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From: franklin in
1994 high idle problem
took my 1994 for its first drive today(bought the car wrecked a couple of years ago and i dont know how long it sat before that). drove it for 50 miles to check it out. ran great and everything worked fine. it would idle at around 1800 rpm in gear as i was driving. could let off the gas and it would still run 55 mph or close to it. when i would give it gas it drove fine. when i would put it in nuetral and try and give it gas it would stumble as if it were running out of fuel. put it back in gear and it would do fine. shut it off and it would not start. it would crank fine but would not fire. pushed the peddle all the way down and it started up and would do the same thing witk the gas peddle. any ideas? thanks
Burning Brakes
Joined: Nov 2008
Posts: 995
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From: Naples Campania
I would definitely do a top to bottom tune. Drain the tank, run some water remove through, OHM the injector, replace all spark wires and plugs, replace air filter and run a couple of tanks of gas through with fuel cleaner.
My main concern would be the gas.
My main concern would be the gas.
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From: franklin in
no doubt a tuneup wont hurt but i fail to see how that would cause the symptoms. while i have been working on the car and moving it around the garage it has started fine and took gas fine. only when i drove it did it start idling high. just went out and car still shows 140 degrees and did not want to start till i mashed peddle to the floor(like a carbed car that was flooded)then it started right up. still would not take gas(when you push peddle it has a flat spot then revs up) put it in gear and it will accelerate fine, no flat spots. will try again in the morning when its cold.
Le Mans Master
Joined: Jan 2006
Posts: 5,621
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From: Orlando FL
The first item I would check for this problem is the idle speed control motor. Make sure it is connected and I would pull it out and give it a good visual inspection. Look at the seat where the plunger makes contact for any excess carbon build up.
You might try to clean the motor and see what results you get. If you get an improvement, I would then get a new IAC motor. I personally hate to clean them, they never seem to hold up for me.
Another thing you might try is to remove the battery cable for 30 seconds to re-set the PCM. I have seen on occasion the idle not targeting the correct speed where is was a temporary software problem. That is just a quick and easy check.
If the IAC is frozen it may cause all kinds of running and starting problems. Before you go off and attack everything at once, fix first things first. That may correct other conditions. But if you do then have other problems, then you can address them progressively.
You might try to clean the motor and see what results you get. If you get an improvement, I would then get a new IAC motor. I personally hate to clean them, they never seem to hold up for me.
Another thing you might try is to remove the battery cable for 30 seconds to re-set the PCM. I have seen on occasion the idle not targeting the correct speed where is was a temporary software problem. That is just a quick and easy check.
If the IAC is frozen it may cause all kinds of running and starting problems. Before you go off and attack everything at once, fix first things first. That may correct other conditions. But if you do then have other problems, then you can address them progressively.
Racer
Joined: Oct 2010
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From: Providence RI
before you even unscrew the first iac mount, do this..
shut it off..
let it cool...disconnect your neg battery cable for ten seconds or so,
reattach the battery cable,
get in the car..put your foot half way down on the gas peddle,
turn on the ignition..let it start..take your foot off the gas...
let the car idle for 10 solid seconds..count em down, one magilla, two magilla, then shut it off..and without touching gas..restart it for five seconds, one magilla two magilla, and off.
make sure its either in park, or clutch in..if manual when you do this.
the ecm will re-set the idle automatically, when you restart the car..if you listen you will hear all kinds of imput and changes..as you wait till it goes out of closed loop..hope this works for you..best, Derek.
shut it off..
let it cool...disconnect your neg battery cable for ten seconds or so,
reattach the battery cable,
get in the car..put your foot half way down on the gas peddle,
turn on the ignition..let it start..take your foot off the gas...
let the car idle for 10 solid seconds..count em down, one magilla, two magilla, then shut it off..and without touching gas..restart it for five seconds, one magilla two magilla, and off.
make sure its either in park, or clutch in..if manual when you do this.
the ecm will re-set the idle automatically, when you restart the car..if you listen you will hear all kinds of imput and changes..as you wait till it goes out of closed loop..hope this works for you..best, Derek.
Racer
Joined: Oct 2010
Posts: 499
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From: Providence RI
secondly..is the DIC lit up like a christmas tree..check engine light?
jump pins 4 and 16 in your aldc..are you reading any codes?
any H code..those are history codes, if you dc the battery
H codes will clear..but are you still reading other codes in the modules..
you will find all you need to read about them here, by search. but if you
are NOT throwing any codes, start slowly with the obvious..
take your time, one small step..if you pull it all down..you are going to regret
the cascading mess you find, as you change one thing..only to suspect another..
you have to solve one issue..completely..before going on..or it will drive you nuts.
get the FSM...and a good DVM, and start slowly..live and learn your car..if it falls on it's
*** away from home, you need to know it...inside out. do it systematically..
don't hear Opti, and think bad opti, prove it out, by isolation. if its not air, its not fuel, it has to
be electrical, or damn..even mechanical !.. you have to take your time and research, and test.
thats the fun of the whole ownership experience ..solving this stuff,!!! Best to you, Derek
jump pins 4 and 16 in your aldc..are you reading any codes?
any H code..those are history codes, if you dc the battery
H codes will clear..but are you still reading other codes in the modules..
you will find all you need to read about them here, by search. but if you
are NOT throwing any codes, start slowly with the obvious..
take your time, one small step..if you pull it all down..you are going to regret
the cascading mess you find, as you change one thing..only to suspect another..
you have to solve one issue..completely..before going on..or it will drive you nuts.
get the FSM...and a good DVM, and start slowly..live and learn your car..if it falls on it's
*** away from home, you need to know it...inside out. do it systematically..
don't hear Opti, and think bad opti, prove it out, by isolation. if its not air, its not fuel, it has to
be electrical, or damn..even mechanical !.. you have to take your time and research, and test.
thats the fun of the whole ownership experience ..solving this stuff,!!! Best to you, Derek
Last edited by Docderek05; Aug 15, 2011 at 04:27 PM.
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From: franklin in
tried to get the computer to reset the idle but it did not change anything.engine did not idle up or down like the computer was trying to reset. engine still idles high and does not want to restart till i hold on the floor like a flooded engine. no check engine light. have not tried to see if i have codes yet. someone borrowed my scanner. when i got the car the mass airflow sensor was unpluged and i plugged it back in. when i unplug it the engine will take fuel fine when it is in park. plug it back in an it has a flat spot when you push peddle down. put it in gear and takes gas fine.
changed the IAC and that did not change anything
changed the IAC and that did not change anything
Le Mans Master
Joined: Jan 2006
Posts: 5,621
Likes: 206
From: Orlando FL
JUst for the heck of it, check out the EGR valve. Make sure it is not frozen, stuck open or whatever, and that vacuum can actuate it.
Also check out the throttle plates and make sure that they are able to close all the way. Maybe something is binding or holding the linkage.
Also check out the throttle plates and make sure that they are able to close all the way. Maybe something is binding or holding the linkage.
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