Weird Idle

[Mazda323-87]

right, this is how the story starts.

I fill up at the station on Empty then In this last hour been driving through town,

about half way through I stop for the lights and my idle just drops (aint got a tacho but shit was noticeable was shaking the body)

so I keep driving watching my gauges and listening for any funny noises, all normal, stop again for lights it stalls, next lights again stalls, i tried coasting it to test and it stalls (wasn't a smart idea).

So i went to station wondering what was up, did basic checks no water leaking or oil and ect. so went a bit further took the intake box of ( the big black cyllinder that sits on top which has filter in just before carb, took that off so more air flow, that didn't help.) checked for any dampness/water and nothing on leads ect

BTW just recently bridged my amp and i think it has an iffy earth but i no squat all about electrics.

the earth is on a bolt but no paint around the bolt has been scratched, i wanted to but couldn't find a damn flathead or sand paper.

so untill tomorow when i find time to do more work was wondering what you smart lot think. (im only 17 and only been playing with cars for 4 ish years)

Possibilities:

- shit in gas tank went through when I was on empty and is now gone through

- shitty gas from the station?

- electrics gone funny (technical aye )

- idle adjuster has randomly decided to adjust itself (don't even know if possible)

Car: 87 mazda 323 sedan 1300

2x6'' 2x4" 1x1000w sub 1x350W amp (just a starter kit for now)

ONE last thing, just tonight my stereo cut out twice for a second, fuse was allgood but don't know if this has any relevance.

Any ideas or suggestions appreciated all helps my knowledge grow!!!

[CXGPWR]

Sounds like you have sucked up some shit from the bottom or ya fuel tank/ shit gas will do it too. Check ya fuel filter, give the carb a good blast clean, take idle screw out - roughly remember how far the screw was in there so ya can put it back in about the same place(count the turns). with the screw out give it a good blast in there with compressed air. or get the old girl running, rev it up and throw a hand over the carb completly so it sucks all the shitty gas out the carb & burns it. it will choke the motor but it does work well

also check ya contact points gap & the ignition timing.

[NaN]

Water in the gas tank ? pour in .5lt of meths, it bonds with the water, allows it to pass through. Condensation occurs when cars are run empty all the time.

[Ogre]

was it the same grade fuel?ie 98 octane instead of the normal 91 or somthing?My bros BMW used to do just that when running 98 for some reason.Could never work it out.And for the stereo, deff sounds like the earth isnt the best, so maybe try getting some cleaner connection.Also check leads on the battary are tight.

[gibbon]

going off what you said about electrics, measure the voltage across the battery terminals when the car is running, should be abot 14.7 volts. wondering if your alternator is acting up

[Bombsquad]

If it runs fine and doesnt cough of sputter at any other points through the rev range then id say the idle screw just needs a tweak, then if it comes right at a later point after more new gas etc just wind it back out