Rover to Emerald inj resistor and throttle pot Q's
Simon - 22/12/07 at 05:53 PM
Chaps,
I'm trying to get my head around the wiring loom to connect my Emerald up.
The Emeral wiring diagram has a throttle pot with red (+), green (0) and black (-). The Rover throttle pot has green, red and yellow wires. I'd
rather not assume the black and yellow wires do the same thing without confirming
I understand I have to use the resistor pack (because of the Rover injectors I'm using), and that injectors work on a live feed switched off by
the ecu (off switch is after the injector).
From the Rover wiring diagram I've managed to ascertain the resistor pack has two brown/orange feeds (fed by one br/o wire to airflow meter;
other to main relay), which I take it are live, these then come out (via smaller wires) to feed the injectors, which are wired to the ecu.
Does this make sense or have I got it wrong?
Also, what does the Rover thermotime switch do?
Cheers chaps
ATB
Simon
martyn_16v - 22/12/07 at 06:42 PM
quote:
Originally posted by Simon
The Emeral wiring diagram has a throttle pot with red (+), green (0) and black (-). The Rover throttle pot has green, red and yellow wires. I'd
rather not assume the black and yellow wires do the same thing without confirming
Do you have a multimeter that reads resistance? You need to find the pair of leads on the pot that have a constant resistance between them while you
twiddle the pot. These two will be the + and -, and by the process of elimination t'other one is signal.
To work out which way round + and - are measure the resistance between one of them and the signal wire. If the resistance is high at closed throttle
and drops as you open the throttle, that's the +. If the resistance increases as you open the throttle it's the -. This assumes the Emerald
is looking for a rising voltage as the throttle open of course, but I can't see it being the other way round
Don't know about the rest.
mark-wiring - 22/12/07 at 06:53 PM
Having installed an Emerald before make sure there wiring diagram is correct for a start it caused me no end of problems when there drawing was wrong
lol.
Martyn is right the emerald looks for rising voltage on the throttle pot not too sure about the rest would need to study the diagrams properly and
thaen tell you
stevebubs - 22/12/07 at 06:55 PM
quote:
Originally posted by Simon
I understand I have to use the resistor pack (because of the Rover injectors I'm using), and that injectors work on a live feed switched off by
the ecu (off switch is after the injector).
Do you know the impedence of the injectors? If not, use the aforementioned multimeter on resistance setting again and put it across the 2 terminals of
an injector.
If it reads around 13Ohms then you don't need a resistor pack. If if it reads in single figures then you do.
mark chandler - 22/12/07 at 08:06 PM
Simon
The thermo time thing can be ignored, its a timer that works on engine heat for the flappy box ecu, and triggers the extra injector for a short period
of time.
Anyway, here's a good write up on what the resistor pack does, it exists on v12 jags, I ran my V8 landrover using a JAG ECU once to get rid of
the flappy box.
aj6 enginnering
Cheers Mark
[Edited on 22/12/07 by mark chandler]
froggy - 22/12/07 at 09:19 PM
are you using the stock injectors on yours as ive changed my efi to a hot wire set up so i can use bosch greens so i dont run out of fuel
Simon - 22/12/07 at 10:52 PM
Cheers chaps,
Will get a multimeter tomorrow.
As far as I'm aware they're the standard R V8 injectors, but as the Rover runs such low pressure fuel as standard, I'll wind the reg up
to start with (just a bar to start with - anyone know the flow rate of standard injectors?
ATB
Simon
mark chandler - 23/12/07 at 10:22 AM
Simon.
Its not that high unfortunately, I suspect what you need is a set of injectors from a 4.2 SIII jag, these are a straight swap.
If you struggle let me know, I have some on a fuel rail ready to go, although a little dusty.
Regards Mark
froggy - 23/12/07 at 10:23 AM
i think you wil find that the injectors will support around 6psi ,the problem is that finding larger injectors to fit the flapper system is a problem
but the hotwire manifold takes the bosch injectors which gives a much wider choice.i got a set of cosworth greens which are as big as il ever need. i
found this out on the v8 forum from some guys who run turbo rover lumps .it sounds like the resistor pack struggles to awitch the injectors once you
start upping the pressure
Simon - 23/12/07 at 12:38 PM
Froggy,
What's the difference between the two? I've machined quite a lot off my manifold so all sits lower!
ATB
Simon
Simon - 23/12/07 at 06:27 PM
quote:
Originally posted by martyn_16v
Do you have a multimeter that reads resistance? You need to find the pair of leads on the pot that have a constant resistance between them while you
twiddle the pot. These two will be the + and -, and by the process of elimination t'other one is signal.
To work out which way round + and - are measure the resistance between one of them and the signal wire. If the resistance is high at closed throttle
and drops as you open the throttle, that's the +. If the resistance increases as you open the throttle it's the -. This assumes the Emerald
is looking for a rising voltage as the throttle open of course, but I can't see it being the other way round
Don't know about the rest.
Martyn
I now know that green is "-", yellow "+" and red the signal.
Cheers very much
Measure the resistance on the injectors and came up with 2.4 ohms, so looks like resistor required.
Mart
I managed to buy a set of Jag 4.2 injectors of ebay, Not fitted yet as I'd already glued (with sealant) everything together.
Also managed to sort out battery position today as it wouldn't fit where it was as intercoolers now in the way. Dilemma was in the boot (more
wiring) or on passenger footwell. In the end had a brainstorm, made a battery size box, 4" deep cut hole in sheet above passenger footwell, drop
in box, then battery. JD, as they say Pics if required later!
ATB
Simon
mark chandler - 24/12/07 at 10:52 PM
Jag injectors will be good for around 300bhp from memory so you are sorted.
I forget the flow rate but 6/220bhp ~40bhp each, so 8 x 35 =320bhp
When I played witrh mine the pattern was poor, however running in a glass jar with thinners cleaned them up.