For a while I've noticed that when my car is fully warmed up the idle will drop and bounce around 400-500rpm. If I turn on any lights or the a/c, it immediately corrects itself to 850 and doesnt bounce. Could this be caused by a leaking vacuum hose? Im getting about 12hg, and the needle doesnt shake.


I checked the MAP sensor hose, it seems fine. Last oil change and new spark plugs 500 miles ago. This is a mazda reman with 14k, babied since it was put in.


Any ideas? I've been searching for a few hours but found nothing.


Also, this may be unrelated, but when I let off the throttle while I'm cruising slowly I pull around 20hg.

Chris

 

Bump

 

Do the Carb Cleaner test.

Spray it around vacuum lines and the intake manifold gaskets. If the car revs up in the area you spray it, then you have a leak.

My bet would be to check the gasket areas first.

 

I thought the car was suspost to die out with the carb cleaner?

 

that is correct


this test sucks though. Try to pressurize the system instead and youll be able to hear air leaking out. Much easier than trying to spray **** all over your vacuum hoses

 

Check this post:

https://www.rx7club.com/showthread.p...hreadid=256040

 

So this definitely sounds like a bad hose? It's about time to do the hose job anyway.


Chris

 

Check that your clutch up and neutral switch are working correctly.