odd idle issues
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Hotshot
Joined: Oct 2003
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From: Ashland City, TN
odd idle issues
So I fixed my not wanting to idle issue by replaceing the TPS, now it usually idles fine except...
It has this lil quirk it had before, but it went away for a long time. Bascially its like the throttle is sticking, and causeing the engine to run at 3k rpm's. but the throttle isn't sticking, and the TPS isn't sticking. If i get under the hood while its doing this, i can just move the throttle a tad, and it will rev the engine higher, telling me that the TPS is NOT doing this.
This dosn't happen when you first start it up, it runs through the warmup cycle, and then drops to 800-1200 rpm's like normal. It happens when your driveing around most of the time. You press in the clutch to shift, and vroom, it goes right up, and its a pain, cause thats wearing the clutch down to shift it smooth to the next gear.
Stoping at a light with a truck running at 3k rpm's is embaraseing!
What sensor would tell it to idle high like this is my question.
I gotta figure out wher my plug for the code reader is, so i can get the codes, but its not helpfull if nobody can tell me, cause i hear its either under the dash by the middle/driverside, or in the glove box, and I dont see it in either place.
It has this lil quirk it had before, but it went away for a long time. Bascially its like the throttle is sticking, and causeing the engine to run at 3k rpm's. but the throttle isn't sticking, and the TPS isn't sticking. If i get under the hood while its doing this, i can just move the throttle a tad, and it will rev the engine higher, telling me that the TPS is NOT doing this.
This dosn't happen when you first start it up, it runs through the warmup cycle, and then drops to 800-1200 rpm's like normal. It happens when your driveing around most of the time. You press in the clutch to shift, and vroom, it goes right up, and its a pain, cause thats wearing the clutch down to shift it smooth to the next gear.
Stoping at a light with a truck running at 3k rpm's is embaraseing!
What sensor would tell it to idle high like this is my question.
I gotta figure out wher my plug for the code reader is, so i can get the codes, but its not helpfull if nobody can tell me, cause i hear its either under the dash by the middle/driverside, or in the glove box, and I dont see it in either place.
Elder User
Joined: Feb 2004
Posts: 553
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From: North Bend Washington
your IAC, idle air control, might be sticking. It may need cleaning. use some throttle body cleaner in it. You may have to remove it for best results.
your plug for code read out is located on the bracket that holds your relays for pump, computor, etc. it sits on the left fender well inside engine compartment.
your plug for code read out is located on the bracket that holds your relays for pump, computor, etc. it sits on the left fender well inside engine compartment.
Last edited by mike93; May 14, 2004 at 07:30 PM. Reason: add coder read out plug locate
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Hotshot
Joined: Oct 2003
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From: Ashland City, TN
okay, i have noe in there that says something about that. I'll try that one.
If i knew what the IAC looked like, or where it was, i'd check that. BUT I DONT!
I sorta cleaned a sensor that was on the right side of the throttle body today. It has a plug in it like its a presure sensor, i just sprayed some electrical cleaner in there and shook it, it seems to move smoothly.
If this is the right one, should i pull the one that goes to the TB and clean that out too? i think thats where taht would stick if it was sticking.
haynes manual sucks, i think i'm gonna go buy a chiltons(sp)
When it says " yea, the sensor is." then goes to another sentance.
If i knew what the IAC looked like, or where it was, i'd check that. BUT I DONT!
I sorta cleaned a sensor that was on the right side of the throttle body today. It has a plug in it like its a presure sensor, i just sprayed some electrical cleaner in there and shook it, it seems to move smoothly.
If this is the right one, should i pull the one that goes to the TB and clean that out too? i think thats where taht would stick if it was sticking.
haynes manual sucks, i think i'm gonna go buy a chiltons(sp)
When it says " yea, the sensor is." then goes to another sentance.
Senior User
Joined: Mar 2004
Posts: 348
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It sounds like the sensor you cleaned was the "Throttle Air Bypass Valve Solenoid". Here is it's discription from my Ford Manual: TABVS is an electro-mechanical device controlled by the EEC Module. It incorporates a soleniod which positions a variable-area metering valve. This valve is used to control both warm and cold engine airflow into the intake manifold. This allows the EEC Module to control the engine warm and cold speed (rpm), and allow for "no-touch" starting.
I have an 88 F-150 4.9L that has had similar idle probems periodically over the last 16 years. My Ford Helm Shop Manual recommends changing that sensor every 50K. I have cleaned mine several times using Carb cleaner, taking care not to leave the cleaner inside the sensor for too long. I took the piece off the TB and cleaned it too. I did replace it at about 125K, I believe it cost $35-45. If you replace it, the new one should come with both the sensor and the valve it connects too.
JC
I have an 88 F-150 4.9L that has had similar idle probems periodically over the last 16 years. My Ford Helm Shop Manual recommends changing that sensor every 50K. I have cleaned mine several times using Carb cleaner, taking care not to leave the cleaner inside the sensor for too long. I took the piece off the TB and cleaned it too. I did replace it at about 125K, I believe it cost $35-45. If you replace it, the new one should come with both the sensor and the valve it connects too.
JC
Elder User
Joined: Feb 2004
Posts: 553
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From: North Bend Washington
that should be it. small round tube w/ connector and is bolted to the right side of the throttle body. it is flanged to the housing. it will have two small holes in it that you can see when it it removed. I've cleaned it with it removed and when installed. providing you have MAS air flow, whichyou should, you may want to try cleaning w/ it installed you will have remove the air intake from the throttle body, carefull nothing gets in. look inside on the right of both bores and you will see a small hole in each bore on the right just ahead of the throttle plates. this will work best if you motor is could and starts ok as the air bypass will be open more for higher idle when cold. now crank it up and squirt some throttle body cleaner as it is running. this way the idle air bypass will suck in the cleaner. this has worked reasonably well for me. just be carefull around the throttle body with air intake off. and yes haynes manuals suck! chiltons not much better. i've found info at "alldata.com" to be usefull. they also publish all tech bullitins and recall issues.
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Joined: Oct 2003
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From: Ashland City, TN
I took it off, and it is black like my air intake, i think it was running rich while the TPS was screwing up, So, i might take that off and clean the shaaz outa that also, cause thats not cool!
Everything seems to be goign smooth.
you guys are real sticklers about cleaning with break fluid and carb cleaner! haha
I used some GM power rust/grime remover lubricant stuff. bascially uber wd/40 =)
Everything seems to be goign smooth.
you guys are real sticklers about cleaning with break fluid and carb cleaner! haha
I used some GM power rust/grime remover lubricant stuff. bascially uber wd/40 =)
