my mx-3 keeps trying to kill herself!? (bad idle, dies...)

[jen319]

ok.. my apologies if i am posting this incorrectly. i read over all the rules to this site.. i tried searching through the forums on here first, and the closest thread that matched my problem was entitled "electrical, or deeper?" ..what he described that his car is doing is very similar to mine, BUT.. his is manual and was sitting for a few years- not the case with mine.

i have a '94 basic model automatic. she has a bad temper that comes and goes. for a while it will be just when i'm stopped.. she'll try to die and i have to lightly press the gas to keep the rpm gauge stable.. right now though it has gotten worse. it pretty much goes into seizure-like convulsions before dying when stopped, going slow, or going in reverse. and it's especially worse if the AC is on. i basically feel like i'm driving a stick-shift with the balancing act i do with the gas and brake and putting it into park to keep from dying. and when i am stopped, the engine sounds more like a big diesel truck than a lil 'ol purple mazda! putt putt putt... i've had this car for 2.5 years and this is about the 3rd time it has acted up this bad. the last time was earlier this year and i guess it just gradually worked itself out somehow. i'm afraid this time it won't just go away though.

last time a friend looked at it for me and couldn't find the problem. he replaced all of my spark plugs. (didn't help) it's not overheating. the oil was changed two months ago. the battery is fine. i've been told it could be "the something-sensor" or "bad gas" or something "flooded"... and a few other guesses that i can't recall at the moment.... just thought i'd try my luck here since you guys are all mx-3 experts. your advice and help is greatly appreciated!

thanks,
jen

[colinf004]

have you tried re-timing the distributor?
loosen I think its 3 bolts on the disty, move it up and down until you get a good idle. try that out

[colinf004]

if that doesn't work, you might be miss-firing. might need to get your heads done. valve seals might be dammaged

[jen319]

oh yeah.. that was the other one. the same friend that replaced all my spark plugs, messed around with the timing for hours. pretty much had no effect. he works on cars for a living (mainly alignments on big trucks), but couldn't figure it out.

i would have already tried taking it to a repair shop, but i'm just nervous about those places because they try to take advantage of clueless women. i have another friend that's willing to attempt any suggestions i find on here though.

thanks,
jen

[shameem]

Do a tuneup - cap, rotor, wires
Check for cracks/leaks in the intake tube
Clean throttle body - seafoam works great - carb cleaner is fine too.
Run injector/fuel system cleaner with the next few fill-ups.
Re-set TPS
Re-set idle and verify timing (you will have to put the ECU in diag mode before that - otherwise no matter how much you adjust timing/idle - it wont take effect).

[jen319]

thanks so much! i'll definitely try all of these suggestions this weekend

[Daninski]

I would suggest you start with the free stuff like opening the diagnostics box and jumping TEN and Grn then. Set your idle to 650rpm by turning the screw on the top of the throttle body (it'll go to 700 when you remove the jumper). Inspect all the hoses on the top of your engine including the big black rubber one on your intake to ensure you don't have a vaccum leak. Run a bottle of injector cleaner through but you should make sure you burn that tank off within a few days. You could be in need of a new fuel filter as well. If there's only a problem at idle I would consider the cap, rotor and wires last after everything else as that can be a little expensive. You can have the resistance checked on your plug wires. I've found spark plugs can be problematic but if you gas mileage is good then chances are your plugs are fine. Other than that, how's your tranny fluid level?

[SCHIMMLE]

This actually sounds much like a simple vacume hose leak. Almost as if when doing an oil change or what not that one of the hoses were accidentally popped off.

Let me guess, you had to learn how to do the heal toe method of driving. Your toe on the brake and your heal on the gas. Its not really that big of a deal but it should be looked after. Another thing besides the hoses popping off is that they might be getting too old and have become hard and cracked. Just get a vacume hose diagram and have a little look around.

[Mad Cow]

Check the VAF (airflow sensor) mine did pretty much the same thing when it got stuck. If you let it rev down with no load, will it die before it can catch an idle speed?

[fowljesse]

You can check for vaccuum leaks by spraying carb or cleaner around the intake hose (the big black tube with ribs ib it). If your idle changes, it's the problem, and needs to be replaced. This would be a good time to do the CAI upgrade.