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Posted: Mon Jul 13, 2015 12:07 pm
by Quagmire
Having the later style injector design also opens up a whole world of possibility with regard to substitute injectors from a whole myriad of vehicles if you wish to investigate such a thing.

Posted: Mon Jul 13, 2015 12:20 pm
by stevieturbo
The cars I'm referring to aren't that old !

Mitsubishi EVO 8 is still using resistors, not sure about 9 or 10.

Posted: Mon Jul 13, 2015 1:19 pm
by DaveEFI
stevieturbo wrote:The cars I'm referring to aren't that old !

Mitsubishi EVO 8 is still using resistors, not sure about 9 or 10.
I gave the reasons not to use resistors if you have a choice. Can't think of any to design for them.

A persuasive argument would be an example of a maker who changed back to using resistors. :D

Posted: Mon Jul 13, 2015 1:34 pm
by stevieturbo
DaveEFI wrote:
stevieturbo wrote:The cars I'm referring to aren't that old !

Mitsubishi EVO 8 is still using resistors, not sure about 9 or 10.
I gave the reasons not to use resistors if you have a choice. Can't think of any to design for them.

A persuasive argument would be an example of a maker who changed back to using resistors. :D
Clearly if manufactures choose from the outset to use them, there mustn't be an issue, and as you're only looking a temporary install, what does it matter ?
If it gets you running with the least amount of work hassle before the upgrade, go with it ?

Why would a manufacturer change back...if they have been using them for years and havent decided to change away in the first place ?

It would be interesting to know why they still do it, as surely it would be cheaper and easier for them to not have to use a resistor pack.
It just adds wiring, connectors and more parts to use resistors, so that must add manufacturing cost too.

Posted: Mon Jul 13, 2015 4:01 pm
by DaveEFI
It is a bit complicated, but it's not going to be a temporary installation. Hence my wanting to get all the various bugs sorted before proceeding.

My existing low impedance injectors with MS2 don't have resistors. If I wanted to use them with the MS3 and sequential, I'd have to add them. And since I have a horror of botched wiring, would mean a great deal of extra work.

I'd also like the later injectors to get rid of all those unnecessary hoses.

Posted: Fri Jul 17, 2015 3:08 pm
by DaveEFI
Next problem is the dash coolant temperature sensor (single terminal type). The Gems manifold doesn't have provision for one.

Choices are:-

1) Drill and tap an unused 'boss' next to the injection temperature sensor. But maybe not enough 'meat' on it. The correct sensor has a thread OD of 15.5mm - the spare boss is only approx 19.5mm. Is that enough? Would hate to wreck the manifold. I suspect I would.

2) Drill and tap the thermostat elbow. There is a flat on it which looks designed for just this. But then the gauge would only read when the thermostat opens?

3) Some say you can used a spare PWM output from the MS3X to drive a gauge, which would make it programmable. Just using the data from the injection CTS.

Anyone know what the thread for the standard SD1 sensor is? It measures 15.5mm OD, and 18 TPS. My guess is an old imperial size.

Ideally, I'd find a sensor with the same electrical characteristics but with something like a 10mm thread, to fit in the spare boss. But can't find such data anywhere.

Posted: Fri Jul 17, 2015 4:54 pm
by stevieturbo
Just drill and tap for the sensor appropriate for the gauge.

Posted: Fri Jul 17, 2015 4:59 pm
by Coops
when we fitted the efi to the capri we drilled out the center of a rover temp sensor (sd1) and used it as a boss and tapped the hole we drilled to take the ford sender,

Posted: Fri Jul 17, 2015 5:18 pm
by DaveEFI
Because if the heater plumbing, I'd like to use the Gems manifold. There is a pic of it earlier in this thread. It is a very different casting to the hotwire or flapper ones. So there's no place for the sensor.

Posted: Fri Jul 17, 2015 5:20 pm
by DaveEFI
stevieturbo wrote:Just drill and tap for the sensor appropriate for the gauge.
But where? It needs (presumably) a flat surface to seal the sensor and access to the water jacket.

Posted: Fri Jul 17, 2015 5:42 pm
by Coops
which manifold you using?
any pics?

Posted: Fri Jul 17, 2015 5:44 pm
by Coops
thor manifold. just read back
think I have one here will have a look at it over the weekend to see if I can see anywhere to try and help out

Posted: Fri Jul 17, 2015 7:54 pm
by stevieturbo
DaveEFI wrote:
stevieturbo wrote:Just drill and tap for the sensor appropriate for the gauge.
But where? It needs (presumably) a flat surface to seal the sensor and access to the water jacket.
Lots of old temp senders are tapered, so they simple seal as you tighten. Or slap some sealant/PTFE on the threads

Posted: Fri Jul 17, 2015 10:46 pm
by sowen
I'm getting confused here, you're planning on using a GEMS manifold because the heater outlet does not run underneath, but it does not have provision for the two water temp sensors? You are not using a hotwire manifold because it has a steel pipe that runs underneath but has all of the required water temp sensors already in place?

Posted: Fri Jul 17, 2015 10:47 pm
by stevieturbo
sowen wrote:I'm getting confused here, you're planning on using a GEMS manifold because the heater outlet does not run underneath, but it does not have provision for the two water temp sensors? You are not using a hotwire manifold because it has a steel pipe that runs underneath but has all of the required water temp sensors already in place?
I think he's going to stick a carb on it instead lol