I spent yesterday afternoon adjusting the new illuminated needles on my F.
I really wish I had re-read this thread before I did the needle swap-I wouldn't have done it!
I made the swap a couple of weeks ago, and when I had finished the only instrument reading correctly was the fuel guage (At least I think it is, I will have to see if the "E" is where it should be!)
Of the 4 instruments three of the new needles' holes were too big for the spindles, one (speedo) was too tight. The speedo one was easy to sort as I have a set of number drills so just drilled it so it was an interference fit. Glue was the answer for the others,
A word of advice...Don't use silicone as it doesn't grip well enough on the spindle. I used a thick super glue, but looking back plastic model glue may have worked better in the event the needles have to be removed again.
As for the adjustments, The first I attempted was the temp guage. As David recommended I got the car up to temp and glued the needle in the correct position. Of course, once the glue set it was reading too low. Apparently the weight of the needle makes a big difference to how it reads.
I tried adding a bit of weight on the little arm opposite the needle which at least got it onto the dial. As I glued the rotten thing on with super glue it will be staying where it is for now as I don't feel like pulling the cluster apart again. For the time being operating temp will be at 20% on the dial rather than 40%.
The next was the speedo. Like David I hooked up the satnav (Called a GPS over here), got up to a certain speed (40KPH worked for me) and pushed the needle in place. Of course, due to the weight of the needle it was way out!
I found that if I put it on reading high I could pull over and move the needle on the spindle once it hit the stop. (Let's hear it for the interference fit!) It did take several tries to get it right but it's currently reading within 1kph so that's close enough. One thing that the different needle weight caused was a loss of readings under 15kph as the stop point is different.
The last instrument tackled was the tach. I thought this one would be easy, but of course I was wrong! I tried hooking up my old timing light which has a digital tach, and which I haven't needed since I bought the MGF. I couldn't get the tach on the unit to read. Must be something to do with the MGF ignition. Very frustrating!
In the end I hooked up the Toughbook with the Blackbox diagnostic sofrware. Blackbox has a tacho test function where it pings the tach up to 3000 rpm repeatedly. I used this to set the tach reading at 3000rpm, again having to take into account the weight difference in the needle. I put some time into trying to balance the needle by adding weight to the reverse of the needle and this seemed to help.
I'm still not sure if the tach is reading correctly. I'm hoping that the Blackbox setting of 3000rpm is accurate.
Would someone be able to tell me what their tach reads at a steady 30MPH (or 50KPH) in either 2nd or 3rd gear?
That would be appreciated!
Next weekend I will be swapping out my dash and console. I'm hoping that will be more straightforward as it is simple swapping of parts. I do plan to have a bottle of Tequila on hand in case the job goes south.