Alright I kind of have a few problems. First, when ever I have the headlights on, the car runs like sh*t , lots of hesitation. Without the headlights on their is no hesitation what so ever. This is under very light load said 1/7 throttle. My car went to get checked out last week, the mechanic who specialises in rotorarys, said the vacuum hose that is on the y-pipe was loose. I picked it up, and the car ran better than ever, it oringally was shaking violently and stalling with the ac on. Than about 2 days later, its back to the same thing, so maybe its loose again? At a light with the ac on it will shake violently, sometimes stall. This happens wether the lights are on or off; and it happens both in cold and hot weather. I noticed if I have the ac on when I first start the car its ok for around 2-5 mintutes, than it starts shaking at stops. The car has been like this ever since I bought it, I really do not think its a compression issue because the car runs fine otherwise. One more thing, I just put a catback and a downpipe on, the car backfires slightly, is this normal?Anything I can do to fix this?

 

try having your alternator checked, it might not be giving you the right amount of voltage when accessory's are on...

 

Sounds like a a bad grounding problem. I had a similar problem.

You may want to re-ground your car or make extra grounding straps. Or buy something like this:http://cgi.ebay.com/ebaymotors/ws/eB...category=33574

 

Check your ISC solenoid. ISC stands for Idle Speed Control. The first page of this document will explain what it is and what it does. http://www.autoshop101.com/forms/h26.pdf

The Mazda service manual will explain where it's at and how to test if it's broken. You can download a copy at www.iluvmyrx7.com

-s-

 

alright I went to iluvmyrx7.com and than to manuals, under what section is it under, wiring diagram, engine?

 

The ISC is in the engine bay, on or near the throttle body.

-s-

 

does the idle speed go up when the ac is on?

 

if I am in drive, and come to a stop without the ac idle is approx 800, with it on it drops to 600 and shakes violently and stalls.

 

I also do not think it is the tps, as that was replcaed about 4 months ago.....

 

did you get your alt checked?

 

where do I go for that?Somethign I can buy at radioshack to test it?

 

Do the clutch switch first. Cheap and 5 minutes to install. Then try the other stuff mentioned above.

 

^will this work for an automatic as well? I am thinking maybe having all the vacuum hoses replaced will help also.

 

I did a search on the idle speed control, and downloaded the service manual. What am I to look for, I know to look for any kinked hoses, but if I take it out do I clean it or what do I inspect it for?

 

the isc is an electric stepper motor. basicly the ecu will put a plunger in a hole to decrease idle or move it out to increase it. think of it as an ecu controled vac leak. check the alt. should put out about 13.5 or so volts at idle.

 

anyone give me abrief description on how to check volts on alternator, I did a quick search but all of that is concerning how to properly remove it and replace the alternator. Thanks

 

get a volt meter. set to dc volts. start car. place meter terminals on the appropriate battery terminals. should read around 13.5 to 14.7 volts. alot depends on pullies temps elec load etc. you are just looking for more than the battery surface charge. everything stock and working it should read about 14.5 volts.

 

^sounds good will try that, I looked up the idle speed control valve in the service manual, the service manual says thats the problem...Anyways when I go to look at the isc what am I looking for?

 

If you can't learn things like this on your own, just tell your mechanic to check the ISC (idle speed controller). Do you expect us to look through the shop manual and tell you what page to check? Grow up, man. There are only a few hundred pages, it shouldn't take you too long to check all of them. If you're pressed for time, use the index or the glossary.

If you don't like learning proactively and discovering new things without being completely spoon-fed, I'm sure your mechanic will appreciate the business.

-s-

 

^I told you already I found the page, it tells you where it is located what it does and how to remove it. It does not tell you what to look for, for symptons. You need to grow up I was asking a simple question, their was NO need to be disrespectful.