I have a 2004 jeep grand cherokee 4.0L I6 with 156 thousand miles that seems to have an acceleration issue. if im stopped at a light or whatever and if i try to 50% or more of the accelerator it accelerates slowly and the rpms stay at 2000 to 2500 then suddenly jumps to 3000 rpms. also if i do 50% or more of the accelerator the ac stops blowing out of the vents and goes to the floor and if i let up off the gas it goes back to the vents. what could be cosing this issue.
The mode door in the heating/AC system is vacuum controlled.
Have the entire vacuum control circuit inspected for leaks
Especially have the check valve on the intake manifold checked for proper operation, and the vacuum reservoir behind the front bumper inspected for damage.
And yes, a vacuum leak can cause the engine problems you describe.
Tester
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update.
I found out that the vacuum hose for the cruise control was cracked so i replaced it. tomorrow i will drive it and see if that fixed the issue with the ac and acceleration.
and thanks for the info @Tester. thats how i found out that the cruise control vacuum hose was cracked.
Good diagnosis by Tester abobve. I think the older versions the VW Beetle air cooled cars had vacuum powered windshield wipers, and when you were driving up steep hill with your foot all the way to the floor they’d slow way down or even just stop working … lol …
[quote=“GeorgeSanJose, post:4, topic:106147, full:true”]
Good diagnosis by Tester abobve. I think the older versions the VW Beetle air cooled cars had vacuum powered windshield wipers, and when you were driving up steep hill with your foot all the way to the floor they’d slow way down or even just stop working … lol …
[/quote]Not sure about that, but I know they had air-powered windshield washers. The source of that air? The spare tire.