EC15B starts well but stalls after 10 seconds

[Mattir]

Hi,

started the 15 and did start really well as I have the new starter installed. Took idle revs., runs smoothly but stalls after 10 sec.

Suspect the fuels pump, which does make somekind of efforts in pumping but really weak and could be stopped by woiggling the wires. Additionally the wire entrance leaks fuel. Doomed the fuel pump to start retirement as of today.

Any other advice on what do additionally? Will change the fine fuel filter and some fuelhoses as well.

[Muz]

Check for a broken earth wire on the wee black resin box under the seat, its the brain for the oil pressure and water temp, if it gets a faulty earth it shuts down the engine. Plenty of posts and vids on here about it, you can manually cause the fault by moving the wires if it is this unit

[Mattir]

Thanks.

Will check that as well. Will study the electric diagram.

The -15 had slept for about 3 weeks and now this was the 1st start. When I turn the key, normally the fuel pump starts and pumps for a while, but now this did not happen. Might have lost the pump or water temp sensor, we had -25 C some nights. No leaks anywhere though.

The engine stops after a certain fixed time and refers to a shutdown due to a sensor reaching a certain tripping value. After the engine has stopped, one of the warning lights lit but did not memorize which one was it. Will have to check that as well.

The pump is the prime suspect as it behaves strangely and leaks.

[Mattir]

Checked the sensors. Coolant temp sensor circuit open as it should be, oil pressure normally closed as it should be and the air filter pollution sensor normally open as it should be. No issues there.

Need to move the troubleshooting to the stop solenoid circuit as it is connected parallel to the fuel pump. We might have a wiring issue or the relay 4 is defective. Or just as Muz suggested, we have poor ground connection of the alarm light box IM1.

The 3rd option is the ”ECU” which is not an ECU at all but some kind of a logic...

[Mattir]

After some moments with the circuit diagram, came across another theory.

The stop solenoid has 2 separate coils. 1st one is energized only during the start and the second coil stays energized if the ”ECU” allows it and keeps it energized through relay R4. Conclusion: need to check the solenoid coil for continuity.

There`s still another suspect:the alternator as it is in parallel with the stop solenoid and fuel pump. The warning light that remained lit when engine stopped was the alternator warning light. Quess I will have to remove the alternator for tests as well...

[Muz]

Have a rattle of the wires going into that box before you go too deep .. every one of them has failed with me, the good news is you can run the machine without it ... try disconnecting the two multiblocks that supply it and see if it stays running ? Water temp senders failing is the other common one, and grounding, together with those relays you mentioned. Its the one connected to the timer that goes faulty.

[Mattir]

Yes, will dig into the wire jungle. The RE4 is in key position as it is normally closed and lets the engine run, but when it energizes, the stop solenoid loses 12V and the engine stops.

Just as you said, the safety circuit can be bypassed by simply removing RE4 and replacing it with a wire. I would still leave the IM1 in place and operative to have functional warning lights.

It is actually strange that the electric components fail while the machine stays unused on the yard.

Additionally thought of the ignition switch as one faulty suspect. If it has poor contact, it cuts the power from the solenoid as well with know consequences

[Mattir]

Foggy evening fun. Tested what happens when the engine started and shuts down. Maybe the test was not perfect but it kept voltage at the fuel pump terminals which means that the RE4 is not energized to trip the stop solenoid. That's good news from the black box point of view.

[Mattir]

Surfed the web and found out that the ECU4 is available for 150€ in a Swedish webshop. Quite a lot for components and plastic worth less than 30€ :)

Still the main suspect is the fuel pump.

Sprayed the starter keyhole with remover oil, dunno the name of the fluid but it is like WD40 but more volatile.

[Mattir]

Changed the fuelhoses, assembled the engine with old pump, wiggled the alternator LR connector and fired it up. Runs smoothly. Don`t know where the fault was, but will change the parts when they arrive. Cleaned the yard of ice and slush. Summer can come.

[Mattir]

After having slept another night, I would sum up the troubleshooting:

If the engine stops:
-Check whether the stop solenoid has voltage in its contacts.
-If not, check for loose contacts in the RE 4 circuitry. Remove the RE 4 and ensure it makes good contact between the contacts that are closed when the relay is not energized.
-Measure sensors: Oil pressure is normally closed, Water temp sensor is normally open, Air filter contaminaton sensor is normally open.
-if the sensors give other values when the engine is not running, you have either a poor sensor or a poor contact issue
-Check that the alternator L+R connector (in white case) has good contact. Take it ff and put some WD40 in it. Put it back.
-only after these steps start suspecting the black box called ECU4 in the diagram.

Good luck. :)

[Mattir]

This issue has now been solved. The fault that caused the engine to shut down after 10 seconds was actually very simple. The RE4 is attached to a holder equipped with flat AMP connectors. One of the connectors was not properly seated and had escaped it`s position and did not make contact. The remedy was simple. Just push the connector to seat properly on the relay flat contact.

Now have new fuel filters, new fuel pump and new fuel hoses. Will fit the grapple next. Then it` s ready for the summer activities- all we need is the summer

[Muz]

The RE4 is attached to a holder equipped with flat AMP connectors. One of the connectors was not properly seated and had escaped it`s position and did not make contact. The remedy was simple. Just push the connector to seat properly on the relay flat contact.

can you give us a pic or a clearer description of what/where this 'RE4 ' is ? is it a relay?

[Mattir]

can you give us a pic or a clearer description of what/where this 'RE4 ' is ? is it a relay?

Yes. RE4 is a relay and sits under the drivers seat in the group of the other relays. Can attach a pic when back home.

[Mattir]

RE4 and newly installed main switch

RE4 is the second one from left. The wires from the relays were loose because the connector was loose.

New 300A main switch, installed it today.

pic is upsidedown... sorry