My 95 Gt I recently purchased had a bad speedo drive gear so i replaced it and now the idle is hanging when i shift. I know the ccrm has some issues but i didn't think they could be related problems? I've tried resetting the idle and cleaning the iac and nothing seems to help. The car also seems week on the top end and sometimes cranks extra long before starting. When it doesn't crank up right away i can turn the key of and try again and it starts right up. I can't stand for things to not be right and its driving me nuts. PLEASE HELP!
I'm about to give up on this thing!
- Thread starter woollums
- Start date
It might help to let us know what else you've done. What about a basic tune-up, plugs, wires,cap, rotor cleaned MAF and that sort of stuff. If you recently bought the car you need to give yourself a baseline from which to work. If the items I just mentioned can't be determined to be relatively new they for all we know are as old as the car. Once you've done these things. clear the trouble codes and check for new ones after a couple of cold to warm cycles. At this point any and all suggestions won't have much value without a bit of history.
Three50won
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woollums, by "resetting the idle" do you mean you adjusted the TPS with a voltmeter? If not then try that. Also try replacing the IAC altogether. If it is malfunctioning then all the cleaning in the world won't help. It's a $50 part at Autozone and if it doesn't fix the problem then just return it. As far as the CCRM is concerned I can't give you any advice on it because I have never ran across any problems with one...sorry.
Never heard of basic tune up stup causing a hanging idle, but all that stuff is good. I don't have mush history on the car. All i see done to it is Flowmasters and IAC looks new, i cleaned the MAF, and i reset the idle based on several post i found on here. Set idle stop screw by tightening it lightly against a .010 feeler gauge, reamove gauge and tighten 1.5 turns in. Then set the mixture screw to 1-2 out, 1.5 in my case. Unplugged battery for 30min then start car and let it idle for 5 min with everything off. Next let idle for 5 min with all accessories on for 5 min. Done.
Everything i've read said you cant set the tps on 94-95 mustangs.
Everything i've read said you cant set the tps on 94-95 mustangs.
Three50won
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woollums, what toyman is saying is that you have to approach idle problems from the ground up. If you just bought a Mustang and you're having idle problem, you don't just start throwing new parts at it. You start with the most basic and easy to fix problems. In many cases it is logical to do a tune up first even if the problems are not tune up related.
You can and should set the TPS on 94 to 95 GTs. I've done it on my 95. Get a voltmeter and find out what the actual voltage is set at. If your idle is hanging then I bet your voltage is too high. It should be 0.98 to 0.99. I understand you did it in a certain procedure but you don't know what the actual voltage is until you check it. Once you set the TPS, then you set the IAC. After setting the IAC you re-check the TPS and adjust it accordingly. In some cases you will have to set the IAC/throttle stop while watching the TPS volts. Then you unplug the battery and see what happens after 30 minutes. Also look for holes in the throttle blade. Sometimes people who run a supercharger will drill the throttle blade to increase the airflow into the engine while the car is at idle. If the car was under forced induction at some point then that might be the case.
Another way to check the problem is to disconnect the IAC and/or TPS to see if the idle changes. Just because that IAC "looks new" does not mean it's functioning properly. And BTW, if you know for a fact that the CCRM is not operating properly then you need to address that first...
You can and should set the TPS on 94 to 95 GTs. I've done it on my 95. Get a voltmeter and find out what the actual voltage is set at. If your idle is hanging then I bet your voltage is too high. It should be 0.98 to 0.99. I understand you did it in a certain procedure but you don't know what the actual voltage is until you check it. Once you set the TPS, then you set the IAC. After setting the IAC you re-check the TPS and adjust it accordingly. In some cases you will have to set the IAC/throttle stop while watching the TPS volts. Then you unplug the battery and see what happens after 30 minutes. Also look for holes in the throttle blade. Sometimes people who run a supercharger will drill the throttle blade to increase the airflow into the engine while the car is at idle. If the car was under forced induction at some point then that might be the case.
Another way to check the problem is to disconnect the IAC and/or TPS to see if the idle changes. Just because that IAC "looks new" does not mean it's functioning properly. And BTW, if you know for a fact that the CCRM is not operating properly then you need to address that first...
Im not by any means a newbie when it come to auto repair, been in a shop all my life. I never just go out buying parts without good reason, thats why im on here.
Low speed fan circuit in the ccrm is bad. I bought a used one on ebay but it has a bad a/c compressor circuit in it and I can't buy a new one for another week or so..
I have unplugged the iac and it stumbles when i unhook it and wont idle at all.
The tps on mine isnt slotted and theres no room for adjustment like the older ones. It doesnt hang with the speed sensor unplugged.
Low speed fan circuit in the ccrm is bad. I bought a used one on ebay but it has a bad a/c compressor circuit in it and I can't buy a new one for another week or so..
I have unplugged the iac and it stumbles when i unhook it and wont idle at all.
The tps on mine isnt slotted and theres no room for adjustment like the older ones. It doesnt hang with the speed sensor unplugged.
Three50won
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woollums, my bad if I sounded like I thought you were a newbie. I've been working with all kinds of different cars all my life but it seems like the simple things always evade me. Or I overlook the most obvious problems. Sometimes it's best to take a step back and start from the beginning with the simplest things is all I was advising. But to be perfectly honest I am out of ideas...sorry. I've never dealt with the speed sensor or the CCRM so I cannot help you there.
I came across this article a few weeks back:
http://www.muscularmustangs.com/tps.php
I'm only posting it here to show you that the TPS on our cars can be adjusted and needs to be whenever you swap out your throttle body. Maybe it'll help you. Good luck with it. I know how frustrating it can be trying to fix problems...
I came across this article a few weeks back:
http://www.muscularmustangs.com/tps.php
I'm only posting it here to show you that the TPS on our cars can be adjusted and needs to be whenever you swap out your throttle body. Maybe it'll help you. Good luck with it. I know how frustrating it can be trying to fix problems...
BlackVert
15 Year Member
cleaning the IAC never works that great. i'd get a new one. the last time i bought one a few years back it was like $40 at pep boys, so it's probably still not that expensive.
That reference is incorrect. The TPS on the 94-95's are not adjustable without elongating the mounting screw holes. In any event that's not necessary as the PCM on these cars use an adaptive strategy. So long as the TPS voltage is between .6v-1.25v the PCM will learn the idle voltage within this range. However, if the TPS voltage is reading close to the outer limits it's best to replace the sensor, especially if it's been in use for 16 years.
Three50won
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Toyman, perhaps you are correct. I was going off the referrence and the fact that I have done this procedure several times on my TPS. Whenever the RPMs were high it was directly related to how much above 0.99 the voltage was. But that also takes into consideration the adjustment screw. If I just move the TPS slightly without adjusting anything else I still see a change in RPMs tho. So perhaps the previous owner used longer screws as you mentioned or modified it to allow for the adjustment. It may be possible that this is the case but everything appears to be factory. Either way thanks for the correction.
Wasnt the iac. I've noticed that it doesnt do it near as bad with the a/c off. Also now it breaks up at around 5000rpm and sometimes is slow to start (cranks longer than normal) unless i let the fuel pump completely cycle.
Could it be fuel pressure related? Im thinking i may have two problems here. I hope the hanging idle issue may go away when i get a new ccrm
Could it be fuel pressure related? Im thinking i may have two problems here. I hope the hanging idle issue may go away when i get a new ccrm
99FiveOh
15 Year Member
Ok, it shows .98 without moving it. Did you gradually open the throttle blade and watch that the voltage increases nice and smoothly with no "flat" spots?
If your idle is hanging in between shifts it's because the computer for whatever reason doesn't know that you've taken your foot off the gas pedal. I know these cars pull timing and/or fuel between shifts. Does your computer have any kind of aftermarket chip installed?
If you pull the PCM you will notice if there is something plugged into the service port. The port unaltered is taped over. It's been a long time since I had the stock PCM and I don't recall if you can visually confirm whether a chip is attached without pulling the PCM.
i don't see anyone ask about aftermarket parts on this car? is the car stock? what all do you have done to it? if you have different heads and such it could just be that you need a tune. i'm assuming it's stock otherwise you would have mentioned it. how old are the o2's? they can fail and start throwing the system off.
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