Generator repair help?

Hi all
I have a rather old Simpower 10kw diesel generator. Must be 40-50 years old. The alternator works, the 3cylinder Nissan diesel engine works, but the engine control module won't let things run (i think).

A few years ago the "auto" start function stopped functioning on the ecm, so I've just been running manual. Now when trying to start it will not cycle the glow plugs or crank.

The Simpower company is no longer in business, no phone, no email. I'm wondering if I should try to get a tractor ignition switch (glow, crank) and just bypass the safeties. I already have to shut down by cutting the fuel to the injector pump...It will run until fuel runs out or I intervene.

Any thoughts about removing the ecm and just running it really dumb?

Ralph

 

wonder if this guy is still around here..
@lapoltba ?

 

I see no issues with running it sans ECM - manual glow plugs were standard on diesel engines for years; you just have to ensure you don't let them run longer than necessary, of things can get expensive quickly... Using a tractor ignition and shutting it down by cutting off the fuel, it will be no different than the 1970s vintage diesel grounds tractor I run at our local fairgrounds. If the ECM has a low oil shut-off feature, I'd definitely figure out how to mimic that.

 

I'm pretty sure there's an oil pressure shut off feature. Presently, the only shut off procedure is Me going out and shutting the unit down. It doesn't owe me anything, I have utility power, solar, wind, batteries, so I just want to have it available if needed. I also have a Yamaha 2800watt generator I can run the house off if needed. Cold winter starts with the gas one is a problem. Below -15C and you really need to have it inside the house to warm up first.

One email got returned from a company that would rebuild the ecm...about $1K. A starter switch would cost from $15 (Amazon) to $60 (specialty shop). I think I'll do the starter switch fix.

The picture attached shows the 2 relays, pre-heat and crank. I'm assuming that if I provide 12v to the signal lead on top of the relay that will energize and operate the relays (one at a time) for test purposes. If that works then the starter switch will too.

Old equipment, what fun!

 

Whats in the grey box on the right? Maybe control relays for the auto-start feature?

To me that whole setup looks "old school" enough where you should be able to trouble shoot, find the faulty component, replace, and be on your way. The top fuse in the block of three looks newer than the other two. Could indicate a previous fault somewhere in the system

 

Those relays appear to share a common power, but separate control sides. Since it's an auto-start unit, what I would expect is that the actual ECU will supply power to the control side of the pre-heat relay for a given time (nb. there may also be a temperature sensor, or connection to the CTS which adjusts the pre-heat duration depending on ambient temp), and shut down pre-heat once it's warm, and then supply power to the control side of the start relay. These may be power-side switched. They could also be ground-side switched, and if that's a solid-state control module in that box, it's very likely they are ground-side switched so you'll have to supply a ground rather than power. Is there no schematic inside the cover? If not, I would start by drawing one out, as best you can. It might make things a little more clear.. Do you have a good DVOM?

 

Good meter available. The pre-heat has a timer operation, about 15 seconds regardless of ambient temp.
The grey box is the ecm.
So for testing I should maybe try a ground to the small terminal on the relay first? If nothing happens try 12 volts?

I'll check for a schematic. Age will likely have faded any ink.

 

Actually, looking at those more closely, it looks like they may be chassis grounded (I don't see a fourth wire now that I'm looking at it on a larger screen). If that's is the case, than the control is definitely power-side switched, and applying 12v to the control terminal should work. If there is a fourth wire, it may indeed be ground-side switched, but you need to determine which before you go applying power to things that don't expect to have power applied to them. If this is a four-wire unit I would use a 12v test light, and start by connecting the test light to ground and applying the tip to the control terminal that comes from the power side; if there's power, then it's always hot, and therefore, ground-side switched. If you get nothing on that terminal, switch the test light to the positive terminal of the battery and check the other terminal for ground; you should get nothing, meaning it's ground-side switched.

 

Thanks John
Applying 12 volts to the crank relay signal post cranks the engine over.
I've purchased a keyed starter switch and a push button switch. The key switch can energize the fuel solenoid (for running, ignition post) all the time on. The start terminal on the switch can be wired to the crank relay signal post for cranking.

It will be dumb as a bag of hammers, no safety cut outs (which always seemed to malfunction anyway), I'll leave the ecm in place for now, see if it needs to be completely removed later.

 

The relays most likely are for glow plugs and pre heat not heavy enough for cranking a diesel.

 

Crank relay CR indeed cranks the engine over when 12 volts is applied to the signal terminal.

Starter switch and push button switch purchased, installation is this afternoon's job.

The starter switch will when:

ON...engage the run relay to energize the fuel solenoid and provide 12 volts to the push button switch (10-15 seconds of glo plug). Key to crank position will provide 12 volts to the CR crank relay to start engine.

OFF...cut 12 volts to fuel solenoid, kill engine. Fuel solenoid is extended when dead (fuel cut off), retracted when energized (fuel available to injector pump)

ACC...no functions planned

Push button switch: With starter switch ON, will apply 12 volts to the pre heat relay for glo plug operation for 10-15 seconds. I didn't want to use a toggle and maybe leave it on.

 

Did a couple of start/runs. 1 hour of exercise and everything works well. Still cheaper to use utility power than diesel. The generator burns 2-2.5 litres per hour. Can get up to 10kwhrs for $2-2.5. Utility power, even at the highest rate would be (including delivery rate etc) about 50 cents for the same kwhrs.

Unit was purchased used 2004. used off grid for 7 years to augment solar and wind. Only about 100 hours per year. Thousands left on it no doubt.

 

Nice!