Little white Eunos

[boggissimo]

Out again last Thursday for a spin with the megasquirt back in, all running nicely and seems to have more power than before, but that might be an illusion. I haven't done anything to the base map so would be surprised if it's better than stock already.

Then Friday was the second rally of the season. Drove over to the start and checked in, but when we got ready to line up for the off, the engine was running lumpy again, like when the MAP line was disconnected. I took off the kick plate in the passenger footwell and checked that the vacuum hose was free, and started again and it seemed back to normal, but when my nav got it, it went rough again, so something was catching the line under there. In the end we started 7 minutes late, the idle was all over the place for the rest of the evening, and the engine died a couple of times when stopped - but we finished the rally and got home OK.

Chatting with atlex about it his suspicion is poor/inconsistent voltage signal from the vTPS, and even if that's not what caused the issues, it still needs sorting. Really need to get my head around this tuning lark, it's all Greek to me still and there are so many variables I really wouldn't know where to start. Should be interesting to find out though!

[boggissimo]

I took the (Hella) vTPS off again to test the resistance and make sure I had the wires connected properly. It seems that the unit must have been faulty as there were some parts of the sweep where the resistance went to infinity, and it didn't change in a linear way. Also, the sensor had a very wide range of rotation (like 300 degrees) so with the 90-ish degrees of movement of the throttle pin, it wasn't using all of the range anyway.

So I bought another one, this time a no-name for £20 off Amazon. Checked the pins for resistance to find which one was which, and after a bit of faffing with swapping the wiring around, I got it on the car and calibrated the Megasquirt. Nice smooth range of signal and very little flicker or instability, so it seems good for now. Went for a test drive and still have some bits and bobs to sort out, but it's definitely more stable. I also tidied up the wiring under the dash and in the engine bay, and sorted the kickplate over the ECU to make sure the vacuum line wasn't getting trapped anywhere.

Another rally tonight so hopefully won't have any further issues...

[boggissimo]

The rally was great fun, car went well and we finished 3rd overall. It was cold but clear and dry, so good conditions to have some fun.


I really need to sort out the exhaust blow/noise as well as the vibrations in the transmission, so will get the car up in the air again later and see what I can find...

[boggissimo]

Took the exhaust manifold off and can see that the mating face was a bit distorted, and the gasket slightly deformed, both from when I trapped the bracket for the water pipe behind it. Not much chance of bending/bashing it back into shape so I put a different gasket on and used some exhaust putty to try to seal the pipes better. Didn't have a chance to start up and see if it's made any difference and it was too cold in the garage to do anything else!