Vortex temperature gauge?
 

Today I picked up Ricola's Vortex and drove back to Nottingham with no real problems. I'm not comfortable with having a non-working temperature gauge though! Rich gave my a spare (cannibalised) insrument pod, and I notice this uses an old-fashioned thermal, bi-metallic strip type of gauge. In this case then it should be easy to fault-find as the gauge is simply connected between a stabilised voltage source in the instrument panel, and the thermistor in the engine acting as a temperature sendor.

The reason for bringing this up here is that the manuals I have seen say that the temperature gauge is a moving-coil one, which could be more difficult to fault-find on.

Anybody got any experience with this?

thanks,
Chris Morriss.

Hi Chris,
As discussed via email, it does work, it just reads low. Hopefully just swapping that part of the cluster will sort it out..
Rich

Before you go playing with the instrument pod, find a MK1 800 temp sender, its easy enough to get to and change, and any decent parts place should have them.
The gauges between the Mk1, and MK1C/MK2 are different, and iirc the engine you have is from a MK1C.

I've swapped the senders before and that made no difference...

Ah right, did you actually manage to source one from an early car? or just the one from the old engine tho, Chris may have never used the right one maybe?

Looking through the technical information, I think it may be that the EFI ECU isn't getting a valid signal from the temperature transmitter. I believe that the bi-metallic-strip temperature gauge has gone high resistance and that therefore the voltage across the sender is too low (this also means the gauge reads far too low). As far as I can see from the techie documentation, the EFI ECU also sees this same voltage signal. If it is too low, the ECU will think the engine temperature is too low. Does the instrument pack put out a regulated 10V for these gauges? In the old days these sort of gauges used 10V but I know that 7V was also used by some manufacturers. I didn't have a chance this last weekend to look into it, but I'm taking the week off work just before Stoneleigh weekend, so I'm hoping for good weather!

I intend to buy the latest K3 ECU from Dave Walker (Emerald) to replace the over-complicated Honda system. Using this will simplify the engine wiring considerably as it uses a direct-fire triple coil pack, although I'm not convinced of my ability to get the fuel and ignition mapping sorted out properly.

Hmmm... Some of what I wrote above won't make sense unless you were aware that as well as the temp gauge not working correctly, the EFI ECU also causes a 'hunting' idle when the engine is hot (The idle oscillates from about 900 rpm to over 1200). I think that the two symptoms are related, hence my comments about the ECU also seeing the temp sender voltage.

Dosn't the latest emerald have a self learning set up?

There are two temp senders on the engine, one for the ECU one for the gauge, they are completly independant systems.

Glad to see you've looked into the Emerald, they really are fantastic :)
You can even interface air con systems with them now to get the increase in rpm when the air con is switched on.

Chris,
I have swapped both temp sensors in the past and they have made no difference to the temp gauge, it has just always read low... The idle thing is a recent problem that did not coincide with any other noticeable changes