Supercharged Honda K20 running issue

[Toilet Duck]

GreenV8S said:

If it was me, at this point I'd be inside the ECU case and following where those ground connections lead. You're looking for an open circuit fault and you seem to have found it within the ECU.

I did undo the four screws and tried to seperate the two halves of the metal case but it didn't want to open. I'm not sure if there is some sort of sealant in there? I thought about using a hot air gun to add a bit of heat to melt any glue but thought better of it. I'll give it another go tomorrow. It must come apart, I was just wary of totally destroying it

[stevieturbo]

Toilet Duck said:

Very true, I can give it a go. In my head I can't see how it would work though if the cct for the IAT and ECT sensors is now being made using an "unrelated" signal ground? If there is no continuity between the different signal ground pins on the ECU, then using a different pin will surely break the circuit? Unless I'm being thick?

Ultimately all grounds will also go to ground. They must be connected at some point. And either way, they will still have a reference ground for those signals to function, which is all they need really.

just backprobe from another sensor with a jumper to one of the one's that's faulty. It'll take about 30seconds to test.

[Toilet Duck]

Morning all, I have an update!

Having exhausted pretty much every avenue, I managed to get hold of a used OE Honda ECU from an Atom owner who had upgraded to Syvecs. I uploaded my custom map and the car now drives without issue, data logs show clean ECT/IAT signals etc with no loss of VTEC. So it was an ECU fault.

I'm still mulling over switching to Syvecs myself. The extra fail safes and engine protection are a big appeal.

Thanks again for everyone's help

[stevieturbo]

Offering it another ground didn't do anything ? that's quite odd.

At least ecu swap has been a success. It can be an expensive swap to Syvecs, but they are the best.