2000 (BJ?) Mazda 323. Dies after 30-40 Mins

My GF has a 2000 Mazda 323 Astina hatch. 1.6l manual. 150,000km. Owned since 2001. Regularly serviced by the local workshop (and some bits by me).

It starts well, idles slightly lumpy but not terrible (she says it's always been like that). It drives well and revs to redline without issue. Generally it's used for local short trips but we have taken it out to Orange, Mudgee, etc

Problem: It stops dead after 30-40 minutes. In January on one of those 40c+ days it died after 9km of driving. I went and had a look (got there in 2 minutes). The engine turns but doesn't show any signs of firing. There was no spark at #1 plug. 10 minutes after I got there it fired to life as if nothing had happened.

1 week ago it did the same after about 10km / 40 mins in stop/start traffic while going through the Harbour Tunnel. It restarted about 1 minute after it stopped.

Yesterday while I was driving it did it again. I'd driven about 17km, the last 2 km idling along in heavy traffic. It was idling fine at the lights and the moment I started around the corner it gave a few splutters and died. It restarted after 5 minutes and drove just fine again. I was buy myself and couldn't check for spark.

Spark plugs were done at 140k.
In-tank fuel filter 142k - I DIY'd this and really wasn't happy about how the fuel pump mated with the filter.

I'd rather not fire the parts cannon at it. The way it initially dies suggests fuel starvation but the lack of any spark or sign of "catching" suggests ignition issues.

I have no idea how to read the codes on this. I don't think it's OBD2 compliant.

Any thoughts?

Comments

  • +2

    Fuel Injectors
    Fuel Pump
    Low Fuel Pressure
    Oxy Sensor (super common in Mazda's)
    EGR Valvle

    When i was working at my old job at a workshop (i was in office mind you) these were the common repairs that solved the exact issue you are having.
    Which one it is… well that needs a scan for engine codes. Take it to a mechanic they will probably be able to scan it and give you the codes (they will prob charge you for the scan)

    Your issue def sounds Fuel / Fuel -O2 Mix Related

    • +9

      Sounds to me like ignition packs are dying/breaking down when they get hot. Op is saying that there is no spark at no.1 cylinder. This is typical of coil packs when they start to fail. They hear soak and just fail. Cool down and off they do again for another short run till they get too hot again

      It's about the only thing you didn't mention.

      • true … coil packs also very common.

        Funnily enough i was going to tag you and be like this is who you need to ask :P

        • +2

          Hahaha… Working my real job today, no time to sit about diagnosing 20yo shit boxes for free… (That and I had a very similar car about this time last week, same issue)

          • +3

            @pegaxs: Lol. I thought your real job was to answer questions on the ozbargain automotive sub forum. My bad.

      • I would have thought coil packs but it seems odd that both would die simultaneously. It has 2 coil on plug ignition coils that work on a wasted spark system. One supplies 1&2, the other 3&4. That's why I think it's something upstream that triggers the coils.

        A bit of googling says the cam sensor. There's also a capacitor just up stream but I'm not sure what it does.

        She took it to her regular guy after the Harbour Tunnel problem but they couldn't find anything obvious (not sure how hard they looked as there was no charge).

        • +1

          Basically this. You have to look for things that get affected by heat soak. Sensors usually have a habit of failing, and not usually getting hot and stopping, cooling down and working again. It could also be the ECU if it is mounted under the “bonut” and it may be failing because of heat.

          Had a Ducati a few weeks ago and it was an issue with the fuel pump relay. It would get hot and just fail… scratch your head for 5 mins, cools down and it comes back on.

          I don’t think it will be something like vapour lock or tank vacuum, as these have other symptoms and the pressures of the fuel rail and the fact that most fuel systems are a closed system makes these unlikely.

  • +2

    Your car issue reminds me of the vanilla ice cream problem had in GM car(s).

  • Air lock in fuel tank? Tank breather getting blocked somehow and not allowing fuel to flow?

  • Yep, don't know how tank breather works on this vehicle, but mud wasps can block any little hole on bikes and car breathers.

  • +1

    BJ?

    Sure. Why not?

    idles slightly lumpy
    .
    stop/start traffic

    Inspect the vacuum line around the throttle body. If this has fallen off or deteriorated then you might be in luck for a quick cheap fix.

    Doesn't it only ever stop in traffic or also while on the move?

    • Doesn't it only ever stop in traffic or also while on the move?

      The first time was on the move in the suburbs on a 40c+ day with AC going full after 10km. The other 2 times it was heavy traffic moving in 1st/2nd gear

  • +1

    I'll put some money on the fuel pump. Next time it happens, try opening the fuel cap for a minute.

    Engine temps are fine?

    • Engine temps are fine?

  • I would check the air intake hose for leaks as these get brittle with age (really common on 323s). If that is fine then I would look at the airflow sensor followed by fuel pressure. I don't think it's the ignition coil because you said only plug #1 doesn't spark as plug #4 would also have same same problem (I am to believe the coil setup is the same as 1.8l). Check for OBD port in drivers footwell. You might have to take it to Mazda so they can read the diagnostics if it doesn't have an OBD port.

  • revs to redline without issue

    It gets redlined? I thought this was bad

    • +1

      The redline is to tell you when you should change gears if the car is manual. It is good.

    • You wouldn't do it all the time but it is within the safe operating range of the engine.

      If you change gears at 2000rpm all the time that will cause problems eventually as well.

      We usually change gears around the 3000-4000rpm point

  • +1

    Coil packs had an in service rework program in 2001(ish)
    Could be shorting out once it warms up.
    Crank sensor can also stop working once warmed up.

    Other things that can cause lumpy idle are a dirty throttlebody, or a worn TPS.

  • +9

    So far you guys have narrowed it down to literally anything that can go wrong with a car.

    I'm going out on a limb and suggest checking your tyre pressure.

    • +5

      Thinking wiper fluid levels.

    • lololololololol 😂

  • +2

    First things I'd eliminate would be related to heat soaking of crank/cam angle sensor and coil packs/ignition module as @blank-404 suggested. These electronic components go through a fair few heat cycles and wear+tear - they do quite commonly fail when hot.

    Easy way of testing this is to keep a can of brake cleaner in the car handy and the next time it stalls, spray liberal amounts of it onto the coil pack or crank/cam sensors to rapidly cool it down, then crank straight away to see if it starts. If you want you can also measure resistance on the secondary circuit when cold and when hot, to see if there's a huge difference or if you get an open when hot (also compare between coil packs).

    • +1

      Would second your comments, had both issues previously on older model cars. If not these likely to be some other electrical problem, usually summer highlights these more so.

  • When it dies, is it just like the key is switched off?

    • Pretty much.

      It will cough across the intersection and then die. It feels too sudden for fuel starvation but I did all my trade on carby cars so there was always fuel in the bowl.

      As I said, it runs beautifully and then suddenly dies.

      • +1

        They spraying some of that freeze spray, or even just tip some water on the cam and crank sensors when it dies. If it fires back up straight away, it points to a faulty sensor.

        Alternatively, you can use a scope or a multimeter (depending on sensor type), and check the sensors for signal when it dies.

  • -2

    It is definitely because of faulty fuel pump.

  • Zoom zoom 😷

  • Have you looked on a mazda forum ? Someone will have had a similar problem at some time ….

    • Had a look prior to here. Lots of parts fired at cars without much diagnosis. Cam sensor seems popular (and makes sense)

  • I had a similar situation once upon a time and it was caused by a filter that stood vertically in the (horizontal) fuel line. Over years it had collected sludge and, after driving for a while, the flow of fuel through the line would push the sludge up against the filter and block the fuel line. Once the engine stopped, gravity took over and the sludge would slowly settle to the bottom, opening a path for the fuel, and the car would start and run again … for a while. It was an easy fix once we figured out the problem.

  • +1

    I signed up to this forum just to answer your question.

    I have a 2002 Ford KQ Laser (re-badged Mazda 323). I was having the same symptoms. Once the engine bay got hot enough, the motor would die and wouldn't start again, though it would crank over fine. Open the bonnet, let it cool and she'd start again. It got worse and on hot days it was bad.

    Initially I thought it might have been the coils. Changed those, no difference. Then I changed the crank angle sensor, still no difference.

    Then I replaced the CAM position sensor - BINGO. No more fault.

    Hope this helps.

    • +1

      Another DX'ing fan. Nice mobile set up in the Laser.

  • +1

    I looked up the method to check the codes for you - it's the old school method. Hopefully this helps you narrow it down.

    https://erwinsalarda.com/how-to-read-mazda-obd-1-codes-witho…

    I'd agree that it's heat related. One thing to check, is do you hear the fuel pump priming when you turn the key to ON (before you start the engine) normally, and then do you hear it after it's died?

  • -3

    Dear Op
    Let me remind you that this car is now a mega 20 years old.
    And 150,000km is still a lot of driving

    Could be anything and everything that is failing

    Time to buy a new car

    • Stupid post.

    • @amayzingone

      very helpful. Thx.

      i'm not going to scrap the old girl for what will probably bee a $200 part.

  • +1

    Not a Mazda, but we had the Nissan Pulsar (03') do that. Would drive ok, then jerk/spatter, kinda like it was low on fuel. Also would die at lights unexpectedly while idling at lights. Turned out to be Crank Angle sensor. Replaced those (and Camshaft sensor. They came in twin pack) and it was fine after that.

    • Same issue on my old VS Commodore, throwing cold water on it made it magically work again for a short time, might be a quick way to diagnose.

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