2.0 petrol stalling when idling or braking

Technical questions and answers about the Mazda Bongo

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Bongolia
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Re: 2.0 petrol stalling when idling or braking

Post by Bongolia » Tue May 09, 2017 10:48 pm

Think back to what you have done in those last checks and recheck everything look again at the wiring to that that throttle pot check the pins are not damaged or pushed back in the plug.
In your image of the dissy you posted earlier you can see the position of the leads just check they are the same as that image.
I think we should swop out the dissy cap and rotor to eliminate them. You may have a Euro Car parts near you they list those items. In the mean time check the following.
Open the engine cover on the top of the engine at the front is the ISC valve. touch the top of it and turn on the ignition but dont crank, you should feel or hear a buzzing as the valve sets itself up.
https://goo.gl/photos/PgeNqWkKqjTKzWMD9
Switch off the ignition

On the near side attached to the chassis rail you will see a black plastic canister next to that that is a small solenoid (purge valve) this degases the tank when you start up
Briefly gasses build up in the fuel tank for a number of reasons emissions regs require these vapours are held in the system,this black canister is where they are held.
https://goo.gl/photos/bjBVWpjRadnm7rxz9

On later vehicles, OBD2 on, the opening of the purge valve is done by the ECU based on readings it receives from sensors around the engine.
From the diag socket I guess yours is not OBD2.
Prior to OBD2 they are simpler in operation. They will open in a number of ways and I am not 100% how the Bongo does this so we can cover three , we only need a result in one.
Switch on the ignition and listen for a click from that purge valve if it doesn't click try cranking the engine and see if it clicks then if it still doesn't click start the engine whilst touching the top of the solenoid and after a bit when the engine warms up it should click.
If yes this would indicate the solenoid is working, it could still fail internally (mechanically) but usually if they click they work.

Next is the crank sensor at the front of the engine by the lower pulley.
Check here for any sign of muck around the sensor particularly at the pick up end. Remove the plug and check the internal pins have not moved up inside the plug and then give the contacts a clean with nail varnish remover and someone elses toothbrush. check the wires at the plug and refit. Next check the pulley itself with the engine running is there any sign of erratic movement or flapping about . If you have a socket big enough check the pulley bolt for tightness.

Now check the engine earth with the multimeter set to OHMS put one end on the block and the other on the chassis you should have reading of less than .75 ohm engine off.Check the charge rate, put the meter across the battery + - set up for DC volts and note what charge rate you are getting immediately after start up.

Now check through all the vacuum pipes these can be tiny and may look like wires look especially around that evap unit.
Best thing to be sure is to check all the rubber pipes you can find doesnt really matter what they are for check them all.
Now check all the induction hoses after the Air Flow Meter (AFM) the thing that sits on the top of the air filter
This one has a blue dot.
https://goo.gl/photos/GKCdAc8mdnkTfn2G9
Look for cracks and splits in the pipework pay particular attention to underside of the duct at the point that it attaches to the engine throttle body at the back of the engine.
https://goo.gl/photos/VxUyZwFnvc7CszrV7

Last on the list for the time being is the Pollution Control Valve (PCV) this pushes into the front of the rocker cover and helps maintain the correct pressure inside the engine whilst not letting any nasty gases out to the atmosphere.Essentially its a one way valve. Its worth noting here that the pipe work from here runs under the manifold to a tee piece these pipes should also be checked.The fit here is not particularly tight but that`s OK providing they are not "falling off" loose.
Remove the valve and suck and blow it should allow air one way and not the other. If you have some carb cleaner or petrol it would be an good time to give that a bit of a flush out. Don`t use nail varnish remover here.
https://goo.gl/photos/2u3EDXNnyYSo3Hp9A
How did that go?
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ade33
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Re: 2.0 petrol stalling when idling or braking

Post by ade33 » Wed May 10, 2017 11:05 am

Bongolia wrote:All the checks are generic so you can do the same on yours. The positioning of sensors etc would be different however. Would be less confusing if you could post another like V6 idle and stall and the chaps could pick it up from there.
Understood, and thanks :)
Enzoforever
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Re: 2.0 petrol stalling when idling or braking

Post by Enzoforever » Tue Feb 13, 2018 12:05 pm

Hi, did this ever get resolved, got similar symptoms
banjo36
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Re: 2.0 petrol stalling when idling or braking

Post by banjo36 » Tue Jun 12, 2018 7:48 am

had a similar problem with bad idling it was the distributor in the end . Water had got into the distrubotor body itself ,After looking at it closely water had collected in a screw cut out built up and leaked down through a joint and into the distrubutor shorting the fuel injector system which is in the distrubotor after cleaning it and spraying all around with silicon spray sorted problem
Enzoforever
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Re: 2.0 petrol stalling when idling or braking

Post by Enzoforever » Sun Jan 06, 2019 7:15 pm

Hi, just wanted to do an update, as I hate it when people just disappear after having problems.

My problem seemed to go away however cold weather appeared along with damp conditions and it reared its ugly head again.

I thought, sod it, ordered distributor cap and rotor, plugs and HT leads. Fitted them in half an hour and hey presto running sweet. Not gonna lie, I'm sure it was probably only one or two elements but I just thought if I replace the lot, I will have a better idea where to go next. The rotor, as I prised it off fell into bits so I think this was probably the main cause, the bakelite or whatever ya call it crumbled.
Bob
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Re: 2.0 petrol stalling when idling or braking

Post by Bob » Sun Jan 06, 2019 7:40 pm

Thankyou. 8)

An update is always interesting and valuable. :wink:
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mikeonb4c
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Re: 2.0 petrol stalling when idling or braking

Post by mikeonb4c » Sun Jan 06, 2019 11:57 pm

Enzoforever wrote: Sun Jan 06, 2019 7:15 pm Hi, just wanted to do an update, as I hate it when people just disappear after having problems.

My problem seemed to go away however cold weather appeared along with damp conditions and it reared its ugly head again.

I thought, sod it, ordered distributor cap and rotor, plugs and HT leads. Fitted them in half an hour and hey presto running sweet. Not gonna lie, I'm sure it was probably only one or two elements but I just thought if I replace the lot, I will have a better idea where to go next. The rotor, as I prised it off fell into bits so I think this was probably the main cause, the bakelite or whatever ya call it crumbled.
Sensible and wise. I sometimes think that, as with aircraft, replacing stuff on a maintenance schedule can be a better strategy than trying to guess too much at whats failed as you spiral earthward. With a petrol engine, ignition system has to be a prime suspect. Thanks for giving an update - might really help the next person. =D>
Flanners
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Re: 2.0 petrol stalling when idling or braking

Post by Flanners » Mon Jan 07, 2019 8:19 am

I failed to replace the cap, rotor arm and leads on my MG F having owned it for 14 years, everything seemed to be absolutely tickety boo all items were original fitment (MY2000, 41K miles), I change oil/plugs/filter/belts etc religiously. I replaced the rotor arm, cap and leads in the Summer and was blown away at the difference. I then decided to do the Bongo similar age/miles (2002, 45K miles) on what looked like original parts, again the engine felt much smoother, better acceleration, tickover and hopefully mpg. Lesson learnt that these are serviceable items and worth doing as you say.
2002 2.0 Aero with Outback Conversion and Roof Top Tent
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