Car Idles Low...
2/10/05, 07:02 PM
#1
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Updates on the Bottom of this page and On Page 2
98 GT Manual...
I've noticed these past couple days that she seems to be idling much lower than usual. Sometimes it gets to only 500 and almost wants to shut off. After reading some of the topics that have dealt with Idle problems, most of the recomendations were to check/clean the mass air sensor and IAC.
My question is this; is what might be causing the low idle the mass air sensor or IAC and if so how would I go about cleaning it?
BTW: I just put in a new K&N filter.
98 GT Manual...
I've noticed these past couple days that she seems to be idling much lower than usual. Sometimes it gets to only 500 and almost wants to shut off. After reading some of the topics that have dealt with Idle problems, most of the recomendations were to check/clean the mass air sensor and IAC.
My question is this; is what might be causing the low idle the mass air sensor or IAC and if so how would I go about cleaning it?
BTW: I just put in a new K&N filter.
2/11/05, 11:15 AM
#2
The IAC you just pull off and spray some carb cleaner in there to get the gunk out. To clean the MAF sensor its a lil more detailed.. Pull it out (you will need a t-20 torx security bit available at autozone) Once you pull it out, becareful to not drop or let the wires touch anything. Use electrical contact cleaner on it by spraying it liberally and let it dry. Only use this type of cleaner as it is designed for devices as this.
2/11/05, 07:46 PM
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ok, looking up some things I found some tips similar to the ones you just gave about the MAF sensor ( although you gave a better description lol ) but for the IAC, where do you spray it? (me doesn't know where the IAC is :P )
Also if I have to replace the IAC how difficult is the installation?
Also if I have to replace the IAC how difficult is the installation?
2/11/05, 11:18 PM
#4
Ok first one shows where the IAC is on your intake. The 2nd pic is mine I took a pic of. Spray excessive amounts of carb cleaner in these ports 
Sorry the pic isnt good. I took the pic about 2 months ago at night for a friend.
Sorry the pic isnt good. I took the pic about 2 months ago at night for a friend.
2/12/05, 02:31 PM
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Not sure what mods you have but when I put in Steeda pullies my idle dropped to the factory 650, which made my lights dim at stop lights. When I got a tune I had them up my idle to 750 - if the IAC valve cleaning does't work and ya got pullies try that.
2/13/05, 08:07 PM
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Its not really rough as it is low. It only has a rough feeling because the engine is almost shutting itself off getting down that low. I just replaced the air filter the night I posted the topic. I replaced it with a K&N finally lol and the car runs fine when its given gas. Its just that once you lay off the gas and the car slows down, it will drop below 500 or close to it.
Just a little example. Driving up to a stop light runs fine and no problems that I can tell. The stoplight turns red and I start to slow down. As I get closer to the light I put it in neutral and bring it to a stop. Between the time Im almost about to stop and the actual stoped position, this is when the engine tends to drop down past 500 or near it. Its not steady there either. It raises and lower somewhat.
It only does it after the car is warmed up and out on the road. The first startup has no problems.
Just a little example. Driving up to a stop light runs fine and no problems that I can tell. The stoplight turns red and I start to slow down. As I get closer to the light I put it in neutral and bring it to a stop. Between the time Im almost about to stop and the actual stoped position, this is when the engine tends to drop down past 500 or near it. Its not steady there either. It raises and lower somewhat.
It only does it after the car is warmed up and out on the road. The first startup has no problems.
2/14/05, 11:23 AM
#13
It honestly sounds like a MAF functionality issue. It sounds like hte computer is having to search for the proper rpm range due to fluctuating maf changes. Defintely clean your maf up. May want to pull it all apart and once you get the sensor out, clean the maf housing and screen with brake cleaner.
Did it happen right after you put the K&N in? K&N's have oil on them and if to much is used, it can get sucked into the intake and across the MAF wires, which can cause all sorts of weird quirks.
Did it happen right after you put the K&N in? K&N's have oil on them and if to much is used, it can get sucked into the intake and across the MAF wires, which can cause all sorts of weird quirks.
2/18/05, 05:56 PM
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whats the normal RPM that these stangs usually run at? "I could have sworn mine Idled at 1k to around 700.
after doing the various tips listed, its still didnt fix it. So we took it to the garage we use. They said that replacing the IAC should have fixed it. Problem is They cant get the car to reproduce what Im seeing. So I was wondering maybe Im in the wrong here and that the Idle is in the right place at about 500 - 600 ?
after doing the various tips listed, its still didnt fix it. So we took it to the garage we use. They said that replacing the IAC should have fixed it. Problem is They cant get the car to reproduce what Im seeing. So I was wondering maybe Im in the wrong here and that the Idle is in the right place at about 500 - 600 ?
2/19/05, 08:12 AM
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Had a similar idle problem, but even worse on my 98 GT, coming to a stop the engine would completely shut down and not restart on occasion, when the car was at operating temp.
The dealer changed the fuel pump and IAC needlesly, the problem turned out to be the crankshaft position sensor, not saying that is your problem, but it could be possible.
The dealer changed the fuel pump and IAC needlesly, the problem turned out to be the crankshaft position sensor, not saying that is your problem, but it could be possible.
3/24/05, 06:55 AM
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Well heres an update:
I took it to the shop again and showed them what it was doing at idle after I had driven it around town for awhile. The one guy told me that what the tach was doing was normal and that it was searching for the proper RPM to be in.
The Engine has started to feel rough at idle now and I guess you could call it slightly surging? About this one they said it could be a number of things dealing with tune up parts.
It just recently started to do this weird Chugging while on the highway. Everyonce inawhile while in 5th gear, I'll accelerate but it will be like "CHUG a CHUG a CHUG a" until I lay off the gas and then get back on it. Everytime this happens I get this feeling of it wanting to shut off. Again the shop said the problem could lie in tune up parts.
I also asked them about checking the crankshaft positioning sensor and they told me it that for that to be a problem it usually gives an check engine light.
I've run out of Ideas here. We're gonna try and clean out the MAF again and my dad wants to look at some parts around the intake himself. I'm being fairly cautious with this garage this time around since the first time I took it in they replaced the new IAC I purchased with a Motorcraft one saying that Fords are very picky about using non-Ford parts. I took the one I purchased back and kept the Motorcraft one and the $200 LABOR FEE :angry:
With the engine stuff said, let me move on to "other" problems.
I just happened to mentioned this in another member's thread but I just started to hear something like a faint whine from the rear. It sounds like a lower tone break squeal. Mostly at low speed and when I turn.
Another noise Im having is actual break squeal. I replaced the pads in the rear but not the rotors and Im still getting a squeal from them. Im also getting squeals from the front now. I was wondering if this is the car telling me in a subtle way :P, "Hey Dumbfart, I need new brakes and rotors!"? lol
Then there is one final thing before I end this post. There has been this "rubbing" sound in my exhaust. I guess to best explain it, just imagine your old childhood bike (but with less spokes. For this example imagine 5 spokes) with a playing card in it. At slow speed you hear a slight "wakka wakka" but as you get faster it becomes more noticeable. Well Im hearing something similar to that coming from the exhuast and I honestly can't pin point the location by sound. After checking with my shop once again, they said it may be the muffler.
Well I must be one lucky son of a... to have all these problems occuring at once lol
I thank you guys for any help or shared experiences you may give
I took it to the shop again and showed them what it was doing at idle after I had driven it around town for awhile. The one guy told me that what the tach was doing was normal and that it was searching for the proper RPM to be in.
The Engine has started to feel rough at idle now and I guess you could call it slightly surging? About this one they said it could be a number of things dealing with tune up parts.
It just recently started to do this weird Chugging while on the highway. Everyonce inawhile while in 5th gear, I'll accelerate but it will be like "CHUG a CHUG a CHUG a" until I lay off the gas and then get back on it. Everytime this happens I get this feeling of it wanting to shut off. Again the shop said the problem could lie in tune up parts.
I also asked them about checking the crankshaft positioning sensor and they told me it that for that to be a problem it usually gives an check engine light.
I've run out of Ideas here. We're gonna try and clean out the MAF again and my dad wants to look at some parts around the intake himself. I'm being fairly cautious with this garage this time around since the first time I took it in they replaced the new IAC I purchased with a Motorcraft one saying that Fords are very picky about using non-Ford parts. I took the one I purchased back and kept the Motorcraft one and the $200 LABOR FEE :angry:
With the engine stuff said, let me move on to "other" problems.
I just happened to mentioned this in another member's thread but I just started to hear something like a faint whine from the rear. It sounds like a lower tone break squeal. Mostly at low speed and when I turn.
Another noise Im having is actual break squeal. I replaced the pads in the rear but not the rotors and Im still getting a squeal from them. Im also getting squeals from the front now. I was wondering if this is the car telling me in a subtle way :P, "Hey Dumbfart, I need new brakes and rotors!"? lol
Then there is one final thing before I end this post. There has been this "rubbing" sound in my exhaust. I guess to best explain it, just imagine your old childhood bike (but with less spokes. For this example imagine 5 spokes) with a playing card in it. At slow speed you hear a slight "wakka wakka" but as you get faster it becomes more noticeable. Well Im hearing something similar to that coming from the exhuast and I honestly can't pin point the location by sound. After checking with my shop once again, they said it may be the muffler.
Well I must be one lucky son of a... to have all these problems occuring at once lol
I thank you guys for any help or shared experiences you may give
