Engine dies w/ AC on

[npresley]

What would cause my engine to want to die at idle when the AC is on?

Thanks for the help,
Nathan

 

[martin]

A little information on the truck might yield better results, year, motor etc.

 

[npresley]

Sorry, 1998 Mazda B2500, manual transmission.

 

[Boomer]

Can ya give me the engine size? Also...does the engine cut out as soon as you turn on the ac or does it happen after it has been on for a while? Was it blowing cold? Can you tell if the compressor is trying to engage or does the engine die before you can tell?

 

[npresley]

It's a 2.5 liter four cylinder. The compressor does come on. It doesn't die immediately. It usually happens if I've been driving and come to a stop. The air is cold. I have noticed that the engine doesn't pick up idle speed, as I have seen other vehicles do when the air is turned on.

 

[npresley]

Would a throttle positioning sensor or an idle valve cause this problem?

 

[Bob Ayers]

Would a throttle positioning sensor or an idle valve cause this problem?

IAC (Idle Air Control) valve would.

 

[Boomer]

I sounds like you have a vacuum leak on one of the lines...which is common for engine stalling when comming to a stop. Check all you lines for holes or tears...a can of starting fluid can sometimes help. With the engine running spray a small amount around each line...if the engine rpm increases at any point, inspect that line you just sprayed. Good luck.

 

[Hardwareman]

Mine used to do that a loooong time ago and it was my IAC valve. I would check for vaccum leaks (even small ones could do it) first before swapping out the IAC though. LAter.




Allen