Mazda Demio Shutting Down

3stagevtec · Postby **3stagevtec** » July 7th, 2016, 4:59 pm

In need of some assistance, have a Demio DY and a few days ago it just started randomly shutting down on me while driving. I changed both cam and crank sensors in an attempt to find the problem none fixed it. Now it shuts down after driving for a 10mins or so, and will refuse to start back until cooled, or left off for a while.

I had it scanned by two mechanics and both were unable to find any faults. It was then suggested to me to carry it by an electrician. Can I get a recommendation for a good electrician in the south area (Sando, Marabella, Gasparillo etc). I can't drive it far with it dying on me.

Fuel pump is working.
New cam sensor.
Changed crank but continue to shut down.
All else seems normal to me.

3stagevtec · Postby **3stagevtec** » July 7th, 2016, 5:11 pm

If no electrician, a recommendation for a good mechanic capable of excellent fault finding skills.

racedriverpro · Postby **racedriverpro** » July 7th, 2016, 6:33 pm

I believe ur maf is the problem start with cleaning it and checking it's connections. If it's bad u will still get the stalling but after a longer period of time. This is cuz it wud be measuring air better than before but still outside parameters.

Especially if it's a hotwire maf.

3stagevtec · Postby **3stagevtec** » July 7th, 2016, 7:35 pm

racedriverpro wrote:I believe ur maf is the problem start with cleaning it and checking it's connections. If it's bad u will still get the stalling but after a longer period of time. This is cuz it wud be measuring air better than before but still outside parameters.

Especially if it's a hotwire maf.

When the car shuts down, it dies totally and won't restart, no matter how much I try. It just tumbles without any signs of attempting to fire up.

The car was scanned twice but none of the mechanics mentioned anything about the MAF. Will look into cleaning it.

racedriverpro · Postby **racedriverpro** » July 7th, 2016, 8:24 pm

Yea the not starting back part can be related to the maf.

FullStop · Postby **FullStop** » July 8th, 2016, 8:05 am

Did you per chance purchase used sensors?

3stagevtec · Postby **3stagevtec** » July 8th, 2016, 10:08 am

FullStop wrote:Did you per chance purchase used sensors?

New for the both I tried. I also made sure the wiring was properly plugged in before attempting to restart engine.

FullStop · Postby **FullStop** » July 8th, 2016, 10:10 am

Sensors have a Mitsubishi stamp or were original Mazda? I've encountered aftermarket knock sensors that don't throw codes but don't function at all

3stagevtec · Postby **3stagevtec** » July 8th, 2016, 12:25 pm

FullStop wrote:Sensors have a Mitsubishi stamp or were original Mazda? I've encountered aftermarket knock sensors that don't throw codes but don't function at all

The original and ones I purchased all were Mitsubishi..

I have NOT changed or tried the knock sensor as yet and was told that could also be responsible for my issues. Will try looking into that soon

FullStop · Postby **FullStop** » July 8th, 2016, 1:57 pm

Knock sensors typically do not cause those symptoms. I would recommend that you stop buying parts in an effort to have the problems rectified, unless you have unlimited cash that it.

If you're interested, and would like to visit my garage, I'll scan the car, if there are no codes, the scan is free, If there are,you pay but at least you're closer to solving the problem.

I'm very curious, but, how's your temperature gauge when the car cuts off? These engines tend to try to protect themselves when overheated, so check they as well.

skylinechild · Postby **skylinechild** » July 9th, 2016, 9:16 pm

FullStop wrote:Knock sensors typically do not cause those symptoms. I would recommend that you stop buying parts in an effort to have the problems rectified, unless you have unlimited cash that it.

If you're interested, and would like to visit my garage, I'll scan the car, if there are no codes, the scan is free, If there are,you pay but at least you're closer to solving the problem.

I'm very curious, but, how's your temperature gauge when the car cuts off? These engines tend to try to protect themselves when overheated, so check they as well.

This sounds like the best deal and OP you should take up this offer.

i do believe you should have the car scanned again as some of these cheaper scan tools these so called "techs" using can only pull generic codes... they cant do manufacturer specific codes nor can they interface properly with all the different computer systems on the car - ECU - TCU - SRS - ABS

another tuner recently had a transmission issues and went by various techs who scanned the car and zero results - i recommended ryotech performance - he scanned the car and picked up the issues.

my $0.2C...scan again.... :idea:

3stagevtec · Postby **3stagevtec** » July 10th, 2016, 12:09 pm

Many thanks for all the suggestions and help, got through with the problem yesterday.. A 3rd mechanic came and had a look, his scan tool also showed no trouble codes etc, but while driving and watching the live data, the car died totally on us and the brain was not visible to the scan tool at that point.

After the car had cooled for around 15mins, we restarted the engine. While fiddling around in the engine bay, the main connector for the brain was tugged and that caused the engine to shut down again. A loose connector within the main harness plug to the brain was responsible. Imagine that!

Thanks again