Megasquirt 18rgeu ignition problem

[jabbatron]

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[thechuckster]

jabbatron: save your MSQ files regularly - tho once you sort out ignition and other electrical noise on the IGN supply, it'll be quite stable. One of the benefits of the megatunix software is how it can keep backup copies of changes and also updates the ECU as you update screens. Nothing worse than working away in megatune and forgetting to write the changes to the ECU. (word of caution: megatunix doesn't use/read MSQ files)

Good to hear you got it running. Is a steep learning curve but ultimately satisfying. Do heaps of data logging and if not already done, fit a wideband O2 sensor.

If you find yourself doing a lot of in-car tuning, get a small 240V inverter. If the ECU is frequently out of the car, get a decent power supply to run it and the stim.


Roger: I used (of all things) heavy-duty microphone cable that I got from Jaycar many moons ago - was 2-core plus sheath. The cable is not rated for engine bay temps but is otherwise fairly robust. Inside the engine bay, I enclosed it in that corrugated wrap stuff. I grounded the sheath at the ECU sensor earth (sorry, can't rememmer what pin that is).

I went this route out of caution - but the DiY autotune guys have a great reputation. If they use the shield as an earth-return, then it shoudl be good. I'd still be cautious of ignition and other noise sources unless it's going into a car that started out life with factory EFI.

I also used the LM1815 circuit instead of the analogue VR interface. no stuffing around 'tuning' the VR signal with the two pots. Just get the pins right at the VR sensor then focus on tuning.

[o_man_ra23]

For a shielded cable with 2 cores, the best stuff to use is a product called Dekoron. Just about any electrical wholesaler (Haymans, L&H etc) should be able to cut you off a bit. Just ask for a few metres of flexible 1 pair shielded instrument cable, they will know what you mean. If they ask what size, 1.5mm or 7/.030 depending on what brand it is... just say the thinner stuff. This gear will be rated for the temps, and the benefit is that it runs a drain wire, so you don't have to try and bundle all the shield bit up. Nice and easy to work with.

[jabbatron]

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[3jcelica]

Looks good, should be a ball terror to drive. Don't expect to get a perfect AFR at idle tune for low manifold pressure. All the guages look good to me.

Get an r31 skyline or Vl TPS it has the D shape required and requires a small braket to fit. Has switches and has resistor style TPS in one unit (i.e. has two connectors).

Roger

[jabbatron]

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[3jcelica]

Jabbatron,

Thats the one, same as what I run, small modification on the mouts to make it fit, the connector with the wires run a varible resistor 0-5 v (if 5v feed is used) and the other runs the switchs which you don't need but could be used to switch stuff at wot ect (e.g. water meth).

O_man,

thanks for the tip on the cables always struggle to find good shielded cable

Roger

[o_man_ra23]

Jabbatron, give me your address and I'll post you my TPS. Its actually off a Pintara, but same as VL. I bought a new one from triggerwheels.com so don't need it. I've already made up the mounting bracket and had it running on my Megasquirt.

[jabbatron]

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