mazda astina ba overfueling problem..... please help

[Mr_Drift]

1994 mazda 323 astina ba 1.8L 5sp

ok so heres the story iv owned my stina ba for about a year now and maybe about 6 months ago discovered an idleing issue.

basically as i travelled along didn't really matter what speed i was doing, i would press in the clutch and my car would basically struggle to idle as the car rolled

this progessivly became worse everyday and sometimes my car would stall whilst rolling (strange thing is its like it had good days and bad days and sometimes the problem wasn't there at all)

the problem has also started to occur when the car was at a complete stop.

originally thought that it had nothing to do with the car overfueling and thought it was the IAC valve being sticky or something so took that apart and cleaned it with throttle body cleaner but the problem still remained.

then thought it might have been the MAF so i cleaned that with air flow sensor cleaner but the problem still remained

then i saw it one day when the car was idleing that it was a fuel issue due to the clouds of smoke and a distinct petrol smell and also the amount of petrol it uses while im driving it

so i was fairly certain it must be a problem with the ECU, so picked up another ECU from the wreckers and removed the old one and installed this one.

problem was completly gone for about 3 months i was so happy

but just the other day for no reason at all problem came back

now im not sure if this ECU suddenly became faulty or why it would spontaneously break on me, so not really sure what the problem is and if it is the ECU i don't want to be replacing it every 3 months

i've put this link to show how it idles (note in this video car is completely warmed up):

http://www.youtube.com/watch?v=UMxurCjIJp0


if anyone can help me it will be muchly appreciated

[70NYD]

I had the same issue. Mine was solved by setting my timing properly that i fudged when i changed my dizzy seal. Do your timing properly by putting car in diagnostic mode and setting it (I didn't have success putting in diagnostic mode so Mazda set my timing for 50) some mechanics don't know how to do this thats why I took it to Mazda
If your timing is good check/change the o2 sensor or leads or plugs or dizzy
That's about the only thing I can think about.

[NaughtyGT]

As tony suggests, save the guess work dude. Run diagnostics using laptop if you can. Even the simple pin test will do but you must first "reset" ECU by disconnecting negative terminal for 2 hrs. Find the problem first. Never change over an ECU unless your sure that's the problem.

Smelling fuel sure sounds like a leaky line though. Can you trace the smell? Otherwise I would have looked @ the dizzy ignitor module. These die slowly & cause arratic idling then, die. tb sensor all those things.

Perhaps may pay you to get Mazda to run diagnostics over car? This way they may pick up other things that are causing poor performance/economy.......

[asanga]

Originally Posted by NaughtyGT

Run diagnostics using laptop if you can.

u cant connect a laptop as its not OBD......only a LED test to count short /long pulses.

Originally Posted by NaughtyGT

"reset" ECU by disconnecting negative terminal for 2 hrs.

dont need that long.....remove negative terminal and press & hold the brake paddle for about 30sec...done!

[70NYD]

Originally Posted by asanga

u cant connect a laptop as its not OBD......only a LED test to count short /long pulses.



dont need that long.....remove negative terminal and press & hold the brake paddle for about 30sec...done!

Yep this why I couldn't do it either. I didn't have a good led setup, so instead of ficking around I took it to Mazda. Wish I actually did it my self, they were playing chicken with my car and the hoist.. And to top it off they parked it nose 1st so I don't notice... Arseholes

[Mr_Drift]

I just ran a diagnostics test on it today and no trouble codes are present, also got the timing done and am still having the same issue with idle but the fuel issue seems to be corrected.

i think the fuel problem and idle were seperate issues.

as i stated before i cleaned the MAF but im thinking that the unit might actually be faulty instead of being dirty, so im thinking of buying a new MAF.

anymore ideas or reccomendations would be great.

thanks guys.

[NaughtyGT]

Originally Posted by asanga

u cant connect a laptop as its not OBD......only a LED test to count short /long pulses

that's a bugger

Originally Posted by asanga

dont need that long.....remove negative terminal and press & hold the brake paddle for about 30sec...done!

nup, @ least not with the Zed! 2 hrs......Cool that's 1 for Mazda

[asanga]

Originally Posted by Mr_Drift

I just ran a diagnostics test on it today and no trouble codes are present, also got the timing done and am still having the same issue with idle but the fuel issue seems to be corrected.

i think the fuel problem and idle were seperate issues.

as i stated before i cleaned the MAF but im thinking that the unit might actually be faulty instead of being dirty, so im thinking of buying a new MAF.

anymore ideas or reccomendations would be great.

thanks guys.

A new MAF will cost you a fortune! I dont think its MAF since ECU is not logging any error codes. IAC on these cars are pretty average, they are just a solenoid valve that opens according to the duty cycle by the ECU. As they get old (your car is over 15 years old) the moving shaft of the valve gets sticky due to wear & tear. This is intermittent and sometimes you even get a delayed response from the valve.

Try resetting your ecu if u think its the ecu.

[paulmac]

Thanks for this great and valueable information guys, its great stuff.