mx5cartalk.com

Hey everyone, just wanting to pick some brains on here.
I'm having this issue with na 1.6 turbo.
When I cold start the car, the car will idle at 2000rpm and stay there, even when the car has warmed up. When it is warm, I can then turn the car off and on again and will idle normally. I have no idea where to look, I changed the ect sensor and still the same. I haven't changed anything in the ecu. Checked for leaks but couldn't find any.
Any ideas where I should be looking?
Thanks

What ECU are you running?

I have a Megasquirt, this happens to me occasionally, but any restart, even a cold restart after realising the idle is high will correct it. Not sure the cause exactly, it's like the idle valve is misinterpreting the signal, maybe a voltage issue?

I don't how your ECU is configured but a standard OEM ECU uses the throttle stop switch, the ECT sensor, the clutch switch and the gearbox neutral switch to determine idle speed. If one or, more often, two of those go bung then idle speed goes way too high.

It needs tuning.

Dann

I'm running a would v500 ecu. It happens every time it's cold and not at running temperature. Just strange that when its warm the car runs great. If I restart it when it's cold it still happens.

I will be getting it tuned again in the near future to run a little more boost. Hopefully it is something in the software, but it's never had this problem before. Was hoping to get it sorted before it got tuned if it were mechanical or electrical. I just assume all those parts are working as when its warm the car runs properly.

I'll just get it tuned again like Dann said, if they find anything, they can fix it.
Thanks guys

I'm assuming you're not tuning yourself?

If you've got access to the software etc, and assuming that ECU has a way to view live data, you can likely plug in the laptop and watch the sensor data etc while it has the issue.

You can often spot something isn't right, usually a sensor reading thats not changing as you'd expect (like a coolant sensor not showing a temp increase as the car idles, or the TPS not showing 0% when the throttle is off, etc)

hks_kansei wrote:I'm assuming you're not tuning yourself?

If you've got access to the software etc, and assuming that ECU has a way to view live data, you can likely plug in the laptop and watch the sensor data etc while it has the issue.

You can often spot something isn't right, usually a sensor reading thats not changing as you'd expect (like a coolant sensor not showing a temp increase as the car idles, or the TPS not showing 0% when the throttle is off, etc)

Nah, wouldn't know where to begin haha. Might take it ti DVS Tuning in syd.
Yeah i checked the sensors and it seems alright.
I'll check the tps again tomorrow with the car off and see what the tps reads closed.
If its not 0% I'll try recalibrating it or just buy another one, only paid $25 for it.
Thanks