From: momf729:
I have a mustang 5.0 and can not get it to stop idling so fast i have set ti down as far as it goes and still doing it can any body help me please.
From: cycleguy4:
I have heard that if you take it to auto zone they have instruments to analyze the system, and if you buy any needed parts there, they will lend you the tools to change parts. Also, it might be a problem with a sensor, about the only way to see what it is, would be to put it on a computer to see whats wrong.
If its an older mustang, It could be one of the fast idle cams on the carb, maybe the choke is sticking a little keeping it at a fast idle. I guess we need more info, year, carb or electronic fuel injection, etc.
Also could be the throttle cable from the gas pedal to the carb sticking slightly inside its casing.
From: momf729:
Hi,
This is her Son, who’s been working on the car. The original trouble codes were for idle air bypass problem, which caused me to replace the idle air control valve. However, now it idles too high, and even adjusting the throttle set screw isn’t affecting it any, neither is unplugging the IAC (its supposed to make the car hesitate). Two trouble codes are present now, one for unable to test idle high rpm range, and unable to test idle low rpm range. (unable to adjust them). I believe it’s still related to the new IAC valve, but not 100% sure.
It is an EFI, and we know the egr valve is bad, but that’s only affected during acceleration, so we know it’s not the problem. My other option is to check for vacuum leaks, and try replacing them one by one to see if the problem is fixed.
Thank you
From: cycleguy4:
a bad egr valve will leak vaccuum , it is a valve that allows intake manifold vapors to be sucked out and stored in the charcoal cannister.
It is an EFI, and we know the egr valve is bad, but that’s only
affected during acceleration
From: kim furnas:
right, but until you give it throttle it’s closed, which is what’s wrong with it now, it just never opens up. When the car’s idle the egr valve shouldn’t even be opened up unless it’s broken. It’s not leaking, it’s stuck closed so when you give it gas it doesn’t open up.
From: savage776949203:
right, but until you give it throttle it’s closed, which is what’s wrong with it now, it just never opens up. When the car’s idle the egr valve shouldn’t even be opened up unless it’s broken. It’s not
leaking, it’s stuck closed so when you give it gas it doesn’t open up.
You have an obvious vaccuum leak. To locate the leak first check to see all the hoses/lines are connected and that there are no open vaccuum ports. (Remember Canisters and Power Brake as well) Use penatrating oil to spray the intake manifold with the engine running. If the RPM changes then you’ve found your leak. Spray the base of the Carb as well, throttle plates wearout and base gaskets get crusty with heat. Be sure that the AC Solenoid isn’t holding the throttle open also.
From: chris&marc:
Did you check the mass airflow sensor located in the air housing yet