RandyLegare
11-07-2000, 11:38 AM
Do you have any suggestion for an intermittent problem I've been having with my 1990 Jeep Cherokee Ltd. edition? It's the four (4.0) litre inline-six engine with multi port fuel injection.
The idle keeps sticking open. I've tried everything to get rid of the problem, but can't get to the bottom of it. The idle sticks once in a while, somewhere between one and two thousand RPM. It will sometimes stick at three thousand RPM's when the Jeep is in park. If you turn the air conditioner on and off it sometimes unsticks the idle...or not. Or, if you shut the engine on and off it may go away. Also, I noticed that when you start the engine it seems to shoot up too high, and is sometimes hesitant to come back down.
I've change the sending unit, the fuel pump...done a couple tune ups and changed the thermostat with no effect at all. I've checked the linkages and throttle and they aren't sticking that I can see.
The high idle seems to increase in likelihood as the car warms up, especially when doing lots of short trips...starting the engine, shutting it off...starting again, etc..makes it more likely that it's going to stick.
This week it's finally gotten worse after three years of this. It's so hard to find as the idle only sticks once in a while and it can go away for weeks at a time. This week it starts out idling normally then within a couple blocks (once it's had a chance to warm up), the idle slowly creeps up to one thousand RPM and stays there. Once you put the car into park the RPM's shoot up to two thousand five hundred and the engine is ready to jump out from under the hood.
I've noticed that the problem seems to get worse it there are any leaks in the cooling system...or it could just be a coincidence.
I think I may have narrowed the problem down to the "Idle speed stepper motor" or the "Throttle position sensor".
Please send any suggestion or help you might be able to offer to my work E-mail address:
Randy.Legare@kone.com
Thanks,
Randy
The idle keeps sticking open. I've tried everything to get rid of the problem, but can't get to the bottom of it. The idle sticks once in a while, somewhere between one and two thousand RPM. It will sometimes stick at three thousand RPM's when the Jeep is in park. If you turn the air conditioner on and off it sometimes unsticks the idle...or not. Or, if you shut the engine on and off it may go away. Also, I noticed that when you start the engine it seems to shoot up too high, and is sometimes hesitant to come back down.
I've change the sending unit, the fuel pump...done a couple tune ups and changed the thermostat with no effect at all. I've checked the linkages and throttle and they aren't sticking that I can see.
The high idle seems to increase in likelihood as the car warms up, especially when doing lots of short trips...starting the engine, shutting it off...starting again, etc..makes it more likely that it's going to stick.
This week it's finally gotten worse after three years of this. It's so hard to find as the idle only sticks once in a while and it can go away for weeks at a time. This week it starts out idling normally then within a couple blocks (once it's had a chance to warm up), the idle slowly creeps up to one thousand RPM and stays there. Once you put the car into park the RPM's shoot up to two thousand five hundred and the engine is ready to jump out from under the hood.
I've noticed that the problem seems to get worse it there are any leaks in the cooling system...or it could just be a coincidence.
I think I may have narrowed the problem down to the "Idle speed stepper motor" or the "Throttle position sensor".
Please send any suggestion or help you might be able to offer to my work E-mail address:
Randy.Legare@kone.com
Thanks,
Randy