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View Full Version : RPM'S jumping up to 2000 RPM'S when coming to a stop.


Rons98SVT
02-28-2006, 08:20 PM
I've got a 98 Cobra with a 5 speed and some times when I come to a stop the RPM's jump up to 2000 RPM and stays there until I cut the car off and restart it. After that she runs fine. Anyone else having troubles like this ?

Stavesacre21
03-01-2006, 02:03 AM
Could be a dirty MAF. Often times occurs on higher-mileage cars that don't get the attention they need.

When you stomp on the gas right away (out of gear), does the car hesitate, or choke for a split second, then jump? I know that when the MAF is dirty, gas/air mix info isn't properly calculated, making the ECU think differently, often times accounting for bad milage AND/OR higher levels of idle.

Oh yea, and if you do need to clean the MAF, or would like to know how to check it, lemme know and I can give you some instructions on how to do so. :D
Aside from that, I'm not really sure what else could be up. I'm sure this bump to the top will catch the eye of a few more smart cobra-wrenchers here! Best of luck with that. :thumbsup:

Rons98SVT
03-01-2006, 07:08 AM
Could be a dirty MAF. Often times occurs on higher-mileage cars that don't get the attention they need.

When you stomp on the gas right away (out of gear), does the car hesitate, or choke for a split second, then jump? I know that when the MAF is dirty, gas/air mix info isn't properly calculated, making the ECU think differently, often times accounting for bad milage AND/OR higher levels of idle.

Oh yea, and if you do need to clean the MAF, or would like to know how to check it, lemme know and I can give you some instructions on how to do so. :D
Aside from that, I'm not really sure what else could be up. I'm sure this bump to the top will catch the eye of a few more smart cobra-wrenchers here! Best of luck with that. :thumbsup:Well it does have high miles but this runs amazing and this little rpm trouble is the only thing that has come up. If you want to email me the instructions that would be great.
Thanks for the reply and I'll check out the MAF. Oh and when stepping on the gas out of gear it doesn't hesitate at all just rev's up fast and strong.

Sonic Blue
03-01-2006, 08:32 AM
There is an idle control valve mounted on the throttle body. They do get gummed up and will hang the idle.

Stavesacre21
03-01-2006, 10:04 AM
There is an idle control valve mounted on the throttle body. They do get gummed up and will hang the idle.
I'd check this out first to see if it looks gummy. If it's not in that bad of shape, i'll let you know how to clean the MAF. :D

Rons98SVT
03-01-2006, 11:06 AM
Will do thanks.

ausie
03-01-2006, 08:34 PM
if niether of those suggestions help, try replacing the PCV valve. Sometimes the valve may stick open in that as well. Also you may want to inspect the throttle plate for buildup which can keep the throttle open a bit (it may need cleaning). Although it sounds more like a sticking IAC (idle air control) valve.

smashedheadcat
03-02-2006, 04:21 PM
Try checking the voltage on the throttle position sensor as well. This can cause the symptoms you describe.