Surging issues
#1
11-05-2007, 07:38 PM
Surging issues
My 95 mustang is currently having surging issues. After being warmed up and then cooled off, then started up again, such as going into a grocery store and coming back out, its surges. I will try to describe surging to me because its kind of confusing. After I start it, the exhaust tone changes from running smooth to also an extreme cam sound. It still has the stock cam. The engine begins to run even lower in rpm and nearly stalls at the first stop I make. I can't tell if its not getting enough air or enough fuel. When I start to drive it while it has its issues, it wants to be sluggish and not have any ***** as if it were missing a few cylinders. The car coasts by surging back and forth, almost trashing me back and forth in the seat. After stomping on the gas in frustration it goes away for a sec as it reaches higher RPM but continues when my foot gets out of it.I have currently replaced all the spark plugs/wires/cap and rotor and still no improvements. My ideas are the throttle position sensor is shot, or the MAF sensor is dirty. Either way I'm not certain and don't want to throw money in parts at it in hopes for results. I have tried disconnecting the battery and such but still no luck. If you need more details on my car just say so. My next bet is to take it to a Ford shop and have the codes ran in hopes for something to pop up. What are your suggestions or ways in which you would work this out? All insight is welcome. Thanks
#2
11-06-2007, 06:19 AM
Surging
Erratic Idle
This is a common problem with the 94-95 5.0 Mustangs, and is almost always related to the IAC, TPS, and even a dirty throttle body. The IAC controls the amount of air entering the engine to control the idle speed. When the IAC fails to do its job properly (dirty, broken, etc.), the idle quality suffers. You may have a surging idle, rough idle, or the car may not idle at all.
If you experience this problem, you may want to try cleaning the IAC. This is done by taking it off the throttle body, and spraying carburetor cleaner into each oriface on it. Replace the IAC onto the throttle body, and crank the car. You may or may not experience a change. Also, you should check your TPS voltage if you have an erratic idle and reset it to .97-.99volts if it is out of range. Lastly, the throttle body can be cleaned by holding it open, and spraying carburetor cleaner to get rid of any deposits..
This is a common problem with the 94-95 5.0 Mustangs, and is almost always related to the IAC, TPS, and even a dirty throttle body. The IAC controls the amount of air entering the engine to control the idle speed. When the IAC fails to do its job properly (dirty, broken, etc.), the idle quality suffers. You may have a surging idle, rough idle, or the car may not idle at all.
If you experience this problem, you may want to try cleaning the IAC. This is done by taking it off the throttle body, and spraying carburetor cleaner into each oriface on it. Replace the IAC onto the throttle body, and crank the car. You may or may not experience a change. Also, you should check your TPS voltage if you have an erratic idle and reset it to .97-.99volts if it is out of range. Lastly, the throttle body can be cleaned by holding it open, and spraying carburetor cleaner to get rid of any deposits..
#3
11-13-2007, 09:41 PM
THESE STEPS MUST BE DONE IN SEQUENCE!!
1. Get engine to operating temp
2. Disconnect IAC sensor plug, if you motor stalls, turn the throttle-stop screw in one full turn and restart, repeat as necessary until engine will idle with IAC unplugged.
3. Set idle using throttle stop. Idle speed will vary depending on the modifications made to your engine. Set it where you are comfy with idle speed.'
4. Set TPS anywhere from .96to.98 volts. This done by loosening the mounting screws, and lightly rotating TPS. If you cant obtain the desired range ,you may need to make the mounting holes bigger by drilling them out.
5. TPS wire colors to probe are generally BLACK and GREEN or GRAY/RED and GRAY/WHITE depending on the car
6. Stop engine. Disconnect negative battery terminal for 15-20 minutes. You may wish to tap brakes or flash headlight a few times to ensure you have purged any remaining power in the system. This will reset the computer to factory settings.
7. Reconnect IAC plug
8. Reconnect battery cable to negative terminal
9. Restart engine.
10. If problem persists, inspect for mass air meter problems and possible vacuum leaks.
This info is from Ford Racing. Wording was slightly modified. But this is right off a fax they had sent for idle setting procedure.
1. Get engine to operating temp
2. Disconnect IAC sensor plug, if you motor stalls, turn the throttle-stop screw in one full turn and restart, repeat as necessary until engine will idle with IAC unplugged.
3. Set idle using throttle stop. Idle speed will vary depending on the modifications made to your engine. Set it where you are comfy with idle speed.'
4. Set TPS anywhere from .96to.98 volts. This done by loosening the mounting screws, and lightly rotating TPS. If you cant obtain the desired range ,you may need to make the mounting holes bigger by drilling them out.
5. TPS wire colors to probe are generally BLACK and GREEN or GRAY/RED and GRAY/WHITE depending on the car
6. Stop engine. Disconnect negative battery terminal for 15-20 minutes. You may wish to tap brakes or flash headlight a few times to ensure you have purged any remaining power in the system. This will reset the computer to factory settings.
7. Reconnect IAC plug
8. Reconnect battery cable to negative terminal
9. Restart engine.
10. If problem persists, inspect for mass air meter problems and possible vacuum leaks.
This info is from Ford Racing. Wording was slightly modified. But this is right off a fax they had sent for idle setting procedure.
IAC - Idle Air Control
TPS - Throttle Positioning Sensor
Hope this was helpful!
http://www.sn95forums.com/Tech/Idle_Fix/index.htm
http://www.sn95forums.com/Tech/Idle_Fix/index.htm
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