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Discussion Starter · #1 ·
I rev my engine when its on park (I have the AOD) and the RPM hangs at 1.2K then drops to 1K and then it very slowly drops down to like 700rpm or 500rpm depending on how long i ran the car. Sometimes when i rev it, it drops down a little and goes back up and down then finally drops back to the normal idle rpm. When im driving and im accelerating then letting it idle, the engine will keep at the rpm i left it after and only when after a while it will go back down to normal. I have cleaned the IAC and the MAF. is it a dirty throttle body because when i took out the plastic tube leading to the throttle body, the butterfly door looked pretty clean. What should i be looking for when i check the throttle body? Could it be the tps going bad?
 

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My 95my has nasty surge problems. My mechanic said to replace both TPS & IAC. However mine does not idle below what it should idlem just over idles and lowers to 1000. I think most cars idle @ 700. When I had my camaro the faulty MAF would made it do that and I had cleaned it with that crc brand spray. After I found out it was the MAF, I had told the mechanic that did me the scan, I had cleaned that sensor twice but he said once that MAF goes bad internally ain't nothing you can do to repair it. True..It seems logical, if damage is inside then your basically screwed, the spray is just to de-contaminate/safely clean anything off on the connectora/pins. My guess would maybe be that you got a bad MAF, but don't take my word for it until im ASE certified lol.

If tb clean then leave it alone. Stuck injector? Bad fuel pump? Clogged fuel filter? I though my camaro had one of those three! I seafoamed it, threw two fuel injection cleaners and it pertained.

Hope this helps. Keep us updated...
 

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make sure your throttle body is clean on both sides of the butterfly valve. I always get an old rag and spray the cleaner directly on it then rub the rag on the outside of the valve and then open the throttle all the way and clean the inside of the valve and the throttle body walls. I do this with the engine turned off.
 

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Try pulling the iac connector while car is off. That will tell you if ECM is making the idle that high... If it does not lower after connector pulled, back out idle stop screw.. With connector still off iac Get it to idle as low as you can 600 or so(make sure car is warm before adjusting idle screw) once you reach a good low idle(as low as you can get it to go) shut off engine.. Plug in iac again, reset tps voltage to .7-.99 pull batt neg cable for 10 mins... Hook back up and take her for a rip.. Allow a few miles for relearn.. And see what you get...

Luk
 

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i have major problems with this too. i've done everything and it's too much to type, but i'm about to get something flamable in a areosol form, and start spraying around the vacuume lines, intake and intake manifolds! hopefully the leak will catch the fumes and raise the idle, so i can find the leak!
 

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i just looked up the VIN of my stang and it turns out that it's originally a 4 sp automatic car!

i bet thats why i'm having alot of my problems- smh
 

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Discussion Starter · #7 ·
If it was the TPS, IAC, or MAF won't the computer throw a code? Because im not getting any codes. Im just getting codes for a lean running engine. 41 and 91. also my coolant sensor is out of range. As for my IAC it is brand new from ford (OEM part). As for cleaning the throttle body, do i have to remove it to clean it? if i remove it do i need to put some adhesive to attach it back on? gasket? Thanks guys.
 

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Discussion Starter · #8 ·
I doubt my MAF is bad. after cleaning it, i got some power back, and it stopped bucking (only happens sometimes, but it stopped now after cleaing). my Maf looks good, the wire isnt broken or anything. just giving more information :)

also, when cleaning the throttle body, is there anything i have to careful with? tips? do i clean the door or the spring?
 

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Leave the throttle body on the engine when cleaning just focus on cleaning around the butterfly area on the outside and inside holding the throttle open by hand and cleaning the throttle bore and the butterfly itself with the engine turned off. Use the CRC brand cleaner.
 

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Discussion Starter · #10 ·
KK, thanx. as for the EGR do you know how to take it off and clean it? Sry for the tremendous amount of questions. I dont want the dealership to diagnose it since i swear they want to take my car for a test drive..... Told me to leave the car with then for an entire day..... -_-
 

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Well the EGR has two bolts holding it on and a tube coming from the exhaust manifold. There is a large nut holding the tube on it and then the two bolts attaching it. Undo those items and unplug it and the vacuum line from it then you can use the CRC spray cleaner to clean it out and you can check the ports on the intake where it is attached. Also take some stiff wire (like a coat hanger) and clean the tube out as well. They will clog over time and then the egr won't function. That will increase NOx emmisions from the car and cause it to fail smog test. I haven't seen any instances where it caused your particular problem but that's not saying it couldn't cause it essentially have a vacuum leak anytime the valve is open to recirculate exhaust gases. HTH.
 

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if your coolant sensor is out of range it wont run correctly either, the computer uses input from that as well as the other sensors, i would fix the coolant sensor and go from there
 

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Discussion Starter · #13 ·
Oh, the rough idle could be the EGR i think because apparently the eec tells me that the egr is stuck open thus air is leaking out of it... (air from egr going into the exhuast causing it to read it as running lean?) How much is a coolant sensor? Was going to pick one up from the JY but decided against it.... Thanx for the input guys. I will clean the EGR and throttle body tmrw. im afraid the carb cleaner will get into the intake. is that ok?
 

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If your pulling code 41, 91 I bet $100 bucks that your air pump is firing in unmetered air to the heads due to your Tab, Tad solenoids not functioning, or leaving the valves open. I just went through all of this myself about a year ago. Damn thing was lean all the time.

The air pump runs air to the heads for the first 20-30 seconds to help with start up and is then diverted to the cat once the engine is warm. If it's not diverted after that, Your maf is only reading what's coming in the intake side. Hence not giving it enough gas for the amount of air your taking in at the heads.

I would check your Tab, Tad solenoids behind pass strut tower, Below EGR solenoid. Look for cracks and damaged wires.

These are discontinued from Ford here in Canada. But LRS has NOS ones from Ford available. Fixed my Car right up!

LUK
 

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Also regarding the Coolant temp out of range. You did pull the codes with the engine warmed up right? It has to be at operating temperature or you'll trigger that code also, in case you were not aware of course.
 

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Discussion Starter · #17 ·
everytime i pull codes i drive it for like 2 hours before i pull codes. so it is all warmed up. plus the low coolant light turns on sometimes and disappears and reappears.
 
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