Ok so when I start my truck it idles great for about 5 minutes then a vaccum leak develops and it idles really rough as if it had a cam in it. Then after about 5 minutes of that the vaccum leak stops and the idle is smooth as silk again. Also when I drive the vaccum leak starts and the A/C stops blowing cold. Then as soon as the leak stops the A/C works properly again. I have no clue where to start on this one. Anybody got any suggestions where to start looking?
Strange vaccum leak/ rough idle
- Thread starter dusted72
- Start date
bremereric
Well-Known Member
Under the dash...
Mopardude
Well-Known Member
My experience with IAC is usually they will get dirty and you won't be able to get your truck to idle till you clean it. I would check the vacum lines under the hood than check the ones under the dash like the other guy said.
Whack the IAC with a screwdriver handle a couple of times. Sometimes that helps to break loose any build up.
As far as checking for vacuum leaks, do it the old fashioned way: grab a can of carb cleaner and start spraying down vacuum hoses, manifold gaskets, etc.
As far as checking for vacuum leaks, do it the old fashioned way: grab a can of carb cleaner and start spraying down vacuum hoses, manifold gaskets, etc.
Filipe
Member
I've red that cuise control problems are related to air conditioner problems.
If it is the case you may look undeneath the battery for a loose, deteriorated, or leaking vacuum supply hose at the spedd control servo.
Battery acid drips on this hose and destroys it. And it has to do with the HVAC.
The Cruise Control and the HVAC use the same Vacuum Reservoir, so if the hose is gone, both systms will fail.
The Vacuum Reservoir is mounted in the right cowl plenum area, under the cowl plenum cover/grille panel. The reservoir contains a one-way check valve to trap engine vacuum in the reservoir.
When engine vacuum drops, as in climbing a grade while driving, the reservoir supplies the vacuum needed to maintain proper speed control and HVAC operation.
Also, the vacuum reservoir may be damaged.
There is a TSB out on this, number 08-22-97. This bulletin involves installin a gasket between the battery tray and the Battery Temperature sensor (BTS) to prevent battery acid from dripping onto the speed control servo vacuum hose and replacing the battery.