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-   MEGAsquirt (https://www.miataturbo.net/megasquirt-18/)
-   -   Running on 2 cylinders at cold start??? (https://www.miataturbo.net/megasquirt-18/running-2-cylinders-cold-start-35382/)

DMRider_10 05-28-2009 02:13 PM

Well, seeing as it was out the car, ad out the case, i thought id try the board in the car without the case on, and stretched all the mod wires out a bit.........

Success! It must have been shorting through the case or summat. Started first go and idled where the cold idle is set to, 1400rpm :) Woo hoo! Just need to take a look at my mods now and figure out whats shorting :) Happy bunny :)

(Just cos I dont know, whats the Gair used for?)

Thanks for the help people

Joe Perez 05-28-2009 02:16 PM

Here's a thought.

I like Brain's idea that something about warmup mode is causing this.

In MegaTune, go to "Basic Settings" -> "Codebase and Outputs function" and look at what's selected for LED18(D15). If it's Warmup*^, then change it to Output 4, and burn. Then, go to "More Settings" -> "Shiftlight/fan/Output 3+4", and make sure that Output 4 (LED18) source is Off, and burn.

See if that makes any difference at all. I'm thinking you may have a short somewhere between the D15 (Warmup) display driver and one of the other two, possibly as far back as the CPU itself (pin 9 to pin 8, for instance.)

Edit: Nevermind. Looks like you found it.

DMRider_10 05-31-2009 07:08 AM

Well I got a lift to my car this morning outside my mates house. Re-flashed the firmware (with ignitor unplugged) and reloaded a stock map with just the req fuel changed. Mangaged to get it started and its running on 2 or 3 again, but again all 4 are firing under cranking. So I warmed it up to see if it was same as before, but no, it stays like that even when warm. Strange thing is, it only happens at low revs/load, it wont idle etc and setting off it a nightmare, holding the revs in one place they jump around, but if you floor it, ie, high load and boost etc, it pulls fine all the way to redline?!

Going out to check my plugs now.

What are the tell tale signs of ignitor failure?

DMRider_10 05-31-2009 07:21 AM

1 Attachment(s)
Attachment 12021

Well ive been out, plugs look ok, all similar looking etc.

Its decided to idle now, AFRs are 20+ so im pretty sure theres unburnt fuel coming out the exhaust, but pulling the leads individually while the cars running, all 4 are arcing to the cam cover?

The revs are fluctuating etc.

Heres a log of it idling with a few blips from me


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