Hello, I have a 1993 3.0L 6 cylinder aerostar. When my wife got home from work today she said that it was acting like it wanted to stall when she was stop at lights stops signs etc. I went out and checked the usual things air filter, which was dirty and i replaced but it didn't resolve the problem, fluids etc. It acts like it wants to stall when stopped and idling, it is worse when it is in drive or reverse with brake on than it is when it is in park or neutral. I don't know if these two are in some way related but I have also noticed the air conditioner and the vent which were working fine yesterday are now not blowing out air through the vents in the dashboard. When I put the dash control switch to air conditioning I can feel cold air coming out of the defrost vents up near the base of the windsheid but nothing out of the dash vents. She told me it was working fine yesterday and even thought it was working this morning as she went to work. I know the clutch is kicking in and out and the canister and line attached to it are cold and sweating when the a/c is switched on. Anybody have any thoughts or suggestions about either of these issues? Thanks

Zing94

 

This is an easy one to diagnose. You’ve got a vacuum leak. Now that the easy part is done the rest is up to you.

Sorry, I just couldn't resist. I'm not familiar with the 3.0 engine but on the 4.0 there is a vacuum tree/manifold that has several vacuum line attached.

When one of the lines comes loose you loose vacuum and have a rough idle and the engine wants to stall.

The vacuum system is also used to control the damper that directs air flow in the heating/cooling system. No vacuum and the door reverts to the default position (defrost)

The vacuum tree on the 4.0 is near the back of the engine on the driver's side near the top of the engine. I can reach mine from under the hood. I can't see and have to re-connect by feel. You might be able to open the access door inside to get to it.

There are hoses that go to several places like the power brakes, the modulator on the transmission, cruse control, and the heat/cool system.

One of your hoses has come loose or broke. Look at all the hoses for holes, crack, or breaks if you can't find one that is off. I was reconnecting a hose on my 94 4.0 on a regular basis until the head gasket went. It's waiting for repair. My 96 hasn't had this problem yet.

Good luck and let us know when you get it fixed.

 

Thanks for the helpful info, I will look at it tonight when I get home and find the one that is leaking, I thought I heard what I thought was a exhaust leak or something so it is probably a vacuum hose that is off or broke. I'll let you know. Thanks again

zing94

 

I have a 3.0, had the same problem, and reattaching the vacuum lines fixed it. Pull off the rear engine cover in the passenger compartment (makes life SOOO much easier) and it's right there. Reattach everything (use hose clamps if some need "persuasion"), and if there is one fitting open, like mine had, use a cap and everything goes back to normal.