Thread: Sitec's 101..

Originally Posted by garrycol

Will the 24v starter turn on 12v and if it does is there enough oomph to start the engine? I assume it has glow plugs and will these work on 12v - albiet if starter or glow plugs work on 12v they will pull a lot of amps so a bigger CCA 12v battery might be needed.

Of course they might not work at all but you never never know unless you try. If they do just stay on 12v with a big CCA.

Garry

No glow plugs as its direct injection. Turns over nicely on 24v and starts instantly. Doubtful if it'd turn over on 12 v, but like the reassuring instantaneous fire up of 24v (even at -7 in Wombat!). I already have the magic box so will prob go down that route.

Originally Posted by Sitec

Yeah, this was the option I was going to take if I don't stay 24v.. There's a 'magic box' badged Monarch Diesel that allows a vehicle to be 12v with two batteries, but when the key is turned gives 24v to the starter. I would have to loose the 24v alternator tho, and the 24v headlights which are awesome!!! Still thinkin!!

Reminds me of fixing electrical problems in 24/12 volt Volvo trucks.

By the time they came to me, they couldn't keep fuses in them, with the wiring it was a rats nest, I found in nearly all cases they had bypassed the original fault with some extra wire and when mostly all that was wrong was that the relays had dust in them and the relay contacts couldn't close properly.

Once everything was sorted, with a wheel barrow full of wire taken out, those Truck's started well, all the ancillaries worked and had strong headlights.

.

Originally Posted by Sitec

No glow plugs as its direct injection.

Hmm I don't understand the link between the two - in my limited experience with diesels - both were Direct Injection and had glow plugs.

Garry

Originally Posted by garrycol

Hmm I don't understand the link between the two - in my limited experience with diesels - both were Direct Injection and had glow plugs.

Garry

Ok, simply put, (left pic) a direct injection Diesel engine has the injector directly atop the piston, giving better economy and better starting, and seldom require glow plugs. Drawback, they're noisy, have a crisp louder sound to them.... (Tdi engine, Cummins engines, Cat engines)

An indirect injection diesel (Right Pic) has a pre combustion chamber which the injector sprays into. Advantages, they're quieter (2.286 Land Rover Diesel, most Kubota Diesels). Disadvantages... Less fuel efficient, poor starters, and require glow plugs.

Common rail diesels are usually direct injection, but instead of having a mechanical timed fuel pump that delivers fuel out at high pressure thru 4 separate lines controlled by a linkage to you're foot, they have an engine driven high pressure pump that continuously supplies a 'Common rail' with fuel. The injectors use this fuel as demand requires.. Each injector is controlled by the ECU, so fuel can be delivered at any time and in any specified amount making them very fuel efficient, assisting with noise reduction, adjusting injection time dependant on engine temp etc.. Great, but technical and full of electrickery.. Not something Im a fan of!!

The Td5 is different again in that each injector is also a fuel pump.... The overhead camshaft operates a plunger on each injector (the bit that looks a bit like half a push rod), fuel is taken and returned thru the small holes around the body of the injector from a sort of low pressure common rail (which is cast into the cylinder head). With the engine running, all injectors are acting like pumps as well as injection. The injectors are controlled in a similar way to common rail injectors using pulses from the ECU to meter the amount injected. The td5 issue is that the wires controlling the injectors are internal under the rocker cover covered in oil.. They have a habit of soaking the oil up then shorting causing inaccurate readings which in turn causes a misfire. Hope this all makes sense!

Originally Posted by Sitec

----- An indirect injection diesel (Right Pic) has a pre combustion chamber which the injector sprays into. -----

Disadvantages... Less fuel efficient ------

You have rocked one of my long held beliefs to core.

I always thought when hot, the precombustion chambered Diesels had better economy than the Direct injection Diesels.

Originally Posted by Sitec

No glow plugs as its direct injection. Turns over nicely on 24v and starts instantly. Doubtful if it'd turn over on 12 v, but like the reassuring instantaneous fire up of 24v (even at -7 in Wombat!). I already have the magic box so will prob go down that route.

I heard one of the 101's trying to start out at the wombat state forest. I think I even commented to someone "that's got no compression at all".... Nope, it was a 24volt starter, it cranked the motor so hard and so fast, you'd swear someone had whipped the plugs out. You'd also be drawing way less current from the batteries at 24volts (well pretty much half the current for the same power).

seeya,
Shane L.