vacum leak??

[zinda]

Hello! I was wondering if anyone knows how to go about checking and if bad fixing a vacum leak. I think that is what is wrong with my car, 94 mazda 626, it was running fine, then a belt started to squeak, so i had the ac/power steering and the water pump belts changed, then it started to idle really bad, so i changed the spark plugs and wires, a little better but it still putts. i bought it two years ago and when i did i replaced the fuel pressure regulator, and a while later i replaced the egr valve and the fuel filter. I have both the books for it but they do not go into much detail about vacum leaks, or maybe i am just missing it, so does anyone have any ideas? or know what i should do?

Thanks

[Jpit]

If you have the Haynes manual it's on page 2C-6 and 2C-7. A quick check is to warm your car up and pull the vacuum line off of the intake manifold. Plug the line with anything such as a cap from a pen. Put your vacuum guage on the intake manifold nipple and you should read between 17 and 22 inches of vacuum at idle. There are several things you can do to check further. Probably want to read that section of the Haynes manual.

When you say that your idle is bad what do you mean? Is it just low? Does it vary in speed? Is your 'check engine light' on? When my idle was low and my car was hesitating it turned out to be the mass air flow sensor was dirty. Cleaning it with brake cleaner or throttle body cleaner takes care of that pretty well on the 4 cylinder car. Not sure what you have for an engine.

[zinda]

you gotta bear with me because i am a chick and i dont understand all of it, like the vacum guage, i dont have one, how much do they cost? anyways, my car is the four cylinder, 2.0 model. and by idleing bad i mean it is erratic. My car is a manual and before i changed the plugs and wires when i would shift into second around a corner it died twice, but since changing plugs it has not done that, and it sounds better at idle, the rpm will jump around a bit, up to 1 1/2 down to 3/4, if that makes any sense. thanks for telling me where to find in the manual and thanks for trying to help, i appreciate it. Could u answer one more question for me? are vacum leaks expensive to fix? my car has 190,000 miles on it and i dont want to pour a bunch of money into it but other than this it runs good and has been maintaned very well, what is your opinion? thanks so much

[Jpit]

Vacuum guages can be purchased for less than $20 at any automotive store. I picke one up for $9 at a bargain outlet. Most of them come with instructions on how to use them.
Your rpm jump is most likely extraneous air entering your intake. One area is that tube and resonance chamber box that sits between the air filter and the throttlebody. If this is leaking in outside air it will give rpm jumps because the mass airflow sensor doesn't sense this extra air. Check that tube and box for cracks or just loose hose clamps on bothe ends.
I would suggest you try posting your problem at www.mazda626.net. There are alot of guys willing to help out and it's a very active site and it costs the same....nothing....and they love helping the chicks out..