29 replies to this topic

[mnr47]

Seeking for some advice. My car Japanese 1.3 SPI engine with coil pack (distributorless ignition). The car has been running good and had no any sort of issue. But last 2 weeks when I start the car after some heavy rain, the car seemed to be misfiring and after awhile it was ok. Then the next day when I start the car again, it was running rough again. 

 

When I checked the HT leads manually by grounding the plug to engine block, noticed I was not getting spark on lead 2 and 3. Hence below will be the things I have done so far but yet no success.

 

1. Changed all 4 HT leads to new. (It was ok for few minutes, the started again rough)

2. Changed all 4 plugs.

3. Checked all vacuum hose(i am using silicone hose)

 

With the above, I thought it was the coil pack has gone faulty, hence I changed to new coil, yet still same issue, HT lead 2 and 3 no spark.

 

Proceed further with below

 

4. Changed new coil

5. Removed and cleaned the crank sensor

 

After all above, the car still not spark on lead 2 and 3.

 

ECU - MNE 101351

 

Appreciate some inputs to check further before I point it to the ECU as faulty.


I have attached some video and picture of my issue to my Gdrive as I cannot upload here as the file is big.

 

https://drive.google...l4M?usp=sharing

 

 

[sonscar]

If you can obtain a pin out of the ecu plug you could measure the continuity of spark 1&4 and 2&3 to compare them.Steve..

[mnr47]

If you can obtain a pin out of the ecu plug you could measure the continuity of spark 1&4 and 2&3 to compare them.Steve..

Sorry, But how to do that? Mind to provide some steps please..

[Bobbins]

The ecu connection is on the underside and can cause issues, I've had the same fault and it was nothing more than a bad connection between the ecu and connecting plug.  It's worth checking and cleaning all the contacts on the ecu and connector, also worth applying a tiny dab of dielectric grease to each pin before reconnecting.

[mnr47]

The ecu connection is on the underside and can cause issues, I've had the same fault and it was nothing more than a bad connection between the ecu and connecting plug.  It's worth checking and cleaning all the contacts on the ecu and connector, also worth applying a tiny dab of dielectric grease to each pin before reconnecting.

 

Thank you for the recommendation, Will try this. In fact I did remove the ECU and left it overnight and checked the socket for any sign of corrosion or damaged. But I never apply any grease when connecting back the socket.  

[Bobbins]

 

The ecu connection is on the underside and can cause issues, I've had the same fault and it was nothing more than a bad connection between the ecu and connecting plug.  It's worth checking and cleaning all the contacts on the ecu and connector, also worth applying a tiny dab of dielectric grease to each pin before reconnecting.

 

Thank you for the recommendation, Will try this. In fact I did remove the ECU and left it overnight and checked the socket for any sign of corrosion or damaged. But I never apply any grease when connecting back the socket.  

 

 

Not normal grease, it needs to be dielectric grease specifically for electrical connections.  On an older vehicle it helps reduce the oxidation on the wiring contacts and maintain a good circuit.

[mnr47]

 

 

The ecu connection is on the underside and can cause issues, I've had the same fault and it was nothing more than a bad connection between the ecu and connecting plug.  It's worth checking and cleaning all the contacts on the ecu and connector, also worth applying a tiny dab of dielectric grease to each pin before reconnecting.

 

Thank you for the recommendation, Will try this. In fact I did remove the ECU and left it overnight and checked the socket for any sign of corrosion or damaged. But I never apply any grease when connecting back the socket.  

 

 

Not normal grease, it needs to be dielectric grease specifically for electrical connections.  On an older vehicle it helps reduce the oxidation on the wiring contacts and maintain a good circuit.

 

 

Noted with thank you. Will try out the dielectric grease.

 

I have cleaned the sockets and connectors for now with some clean cloth and cotton buds, still not getting spark on HT lead 2 and 3.  

[mnr47]

 

 

 

The ecu connection is on the underside and can cause issues, I've had the same fault and it was nothing more than a bad connection between the ecu and connecting plug.  It's worth checking and cleaning all the contacts on the ecu and connector, also worth applying a tiny dab of dielectric grease to each pin before reconnecting.

 

Thank you for the recommendation, Will try this. In fact I did remove the ECU and left it overnight and checked the socket for any sign of corrosion or damaged. But I never apply any grease when connecting back the socket.  

 

 

Not normal grease, it needs to be dielectric grease specifically for electrical connections.  On an older vehicle it helps reduce the oxidation on the wiring contacts and maintain a good circuit.

 

 

Noted with thank you. Will try out the dielectric grease.

 

I have cleaned the sockets and connectors for now with some clean cloth and cotton buds, still not getting spark on HT lead 2 and 3.  

 

 

Still same issue even after done the recommendation. 

[mnr47]

To update : 

 

I manage to loan an ECU from my friend, when tested with his ECU the card starts and run without an issue. Hence I think can conclude that my ECU is at fault.

[Bobbins]

To update : 

 

I manage to loan an ECU from my friend, when tested with his ECU the card starts and run without an issue. Hence I think can conclude that my ECU is at fault.

 

Not ideal but good progress anyway :)

[mnr47]

Still haven't manage to get my ECU checked as we are still in lockdown. 

 

But when I start the car sometimes, it is ok with my current ECU. But sometimes it is running rough as no firing on lead 2 and 3.

 

 

Could this be a faulty crank sensor?

[Wazzah]

Still haven't manage to get my ECU checked as we are still in lockdown. 

 

But when I start the car sometimes, it is ok with my current ECU. But sometimes it is running rough as no firing on lead 2 and 3.

 

 

Could this be a faulty crank sensor?

 

It will not be a faulty crank sensor as it is only effecting one side of your coil pack.

The MNE 101351 is a dual plug ECU.

The smaller plug has 3 wires coming out of it.

The 2 black ones are unused in your car.

There should be a single white wire with a silver trace.

It is in position 18 of the small plug and runs direct to the bosch junior plug under your coil pack.

Your fault lies somewhere in this single circuit.

Check this wire and it's plugs each end for good clean connection and continuity.

The bosch junior crimp connectors are a bit fragile.

I'd be tempted to pull the ECU out of its bracket, pull the little plug and test pin 18 out of the ECU whilst turning the starter over.

No signal would confirm an ECU fault.

Please attend to the simple non ECU things first.

If it is the ECU I may be able to assist in repairs.

I may have a spare MNE 101351 in the coming weeks if I finish my Haltech project.

Regards

Waz

[mnr47]

 

Still haven't manage to get my ECU checked as we are still in lockdown. 

 

But when I start the car sometimes, it is ok with my current ECU. But sometimes it is running rough as no firing on lead 2 and 3.

 

 

Could this be a faulty crank sensor?

 

It will not be a faulty crank sensor as it is only effecting one side of your coil pack.

The MNE 101351 is a dual plug ECU.

The smaller plug has 3 wires coming out of it.

The 2 black ones are unused in your car.

There should be a single white wire with a silver trace.

It is in position 18 of the small plug and runs direct to the bosch junior plug under your coil pack.

Your fault lies somewhere in this single circuit.

Check this wire and it's plugs each end for good clean connection and continuity.

The bosch junior crimp connectors are a bit fragile.

I'd be tempted to pull the ECU out of its bracket, pull the little plug and test pin 18 out of the ECU whilst turning the starter over.

No signal would confirm an ECU fault.

Please attend to the simple non ECU things first.

If it is the ECU I may be able to assist in repairs.

I may have a spare MNE 101351 in the coming weeks if I finish my Haltech project.

Regards

Waz

 

 

Hi Waz,

 

Thank you for the recommendation. Can I test the pin 18 with multimeter while starting the car?

 

Just wondering why sometimes it is ok, and sometimes it is not.

[bpirie1000]

Could be something as simple as a solder joint on the ecu board.

These sometimes rattle themselvesand sometimes it is corrosion to the many joints on the board to sockets and take offs.

Good luck.

Would also suggest try your ecu in your friends car(who lent you their ecu).. see what happends...

[mnr47]

 

Still haven't manage to get my ECU checked as we are still in lockdown. 

 

But when I start the car sometimes, it is ok with my current ECU. But sometimes it is running rough as no firing on lead 2 and 3.

 

 

Could this be a faulty crank sensor?

 

It will not be a faulty crank sensor as it is only effecting one side of your coil pack.

The MNE 101351 is a dual plug ECU.

The smaller plug has 3 wires coming out of it.

The 2 black ones are unused in your car.

There should be a single white wire with a silver trace.

It is in position 18 of the small plug and runs direct to the bosch junior plug under your coil pack.

Your fault lies somewhere in this single circuit.

Check this wire and it's plugs each end for good clean connection and continuity.

The bosch junior crimp connectors are a bit fragile.

I'd be tempted to pull the ECU out of its bracket, pull the little plug and test pin 18 out of the ECU whilst turning the starter over.

No signal would confirm an ECU fault.

Please attend to the simple non ECU things first.

If it is the ECU I may be able to assist in repairs.

I may have a spare MNE 101351 in the coming weeks if I finish my Haltech project.

Regards

Waz

 

 

I have checked the wiring seems all good. Then I have tried to remove the small plug from ecu and tested the pin 18 with test lamp seems no supply. Can this conclude the ECU at fault?

 

The engine still misfire with or without the small plug connected to ECU as well.