Coolant Temperature Sensor - CA18DET

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18-06-2018, 13:24
h0ivik

Coolant Temperature Sensor - CA18DET

Hi!

Info regarding the car:
Stock internals
Stage 3 Horsham chip
GT2860RS
444cc injectors
Z32 AFM
Walbro 255 fuel pump
3 inch exhaust & apexi air filter
FMIC
Plugs are BCPR7ES gapped to 0.8mm

I've been experiencing some troubles with my S13 for a couple of weeks now, I was actually going to make a thread on here regarding those issues, but it seems like I might have found the solution.

So basically, after every startup (didn't matter if engine was cold or hot) it ran bad for a couple of minutes. Kind of hard to explain the exact problem, but when accelerating after startup it felt like someone was applying the brakes every now and then. Another example is, especially when engine is cold, when changing gears then accelerating, it felt like the engine needed a couple of seconds to pick itself up, like it was lacking power or something. After driving for a couple of minutes, it felt like someone turned a switch (literally, it felt like something was turned around), and then it worked perfectly! Cold start was crap as well most of the time, never went higher than 1000 rpm when cold.

It went completely away when I took the plug I had on the AAC unit and changed places with the one on the CTS. Cold start was working as intended again (swapped my air reg last year because it was stuck), rpm's went up to 1500 then slowly crawled down. I did a couple of test runs, unplugging and plugging in the different plugs, and the problem occured again when I used the plug that was connected to the CTS in the first place..

I'm just wondering if there is any way of checking if I have indeed found the correct plug for the CTS (I'd believe so since the troubles have dissappeared), or if I have used the AAC plug and the CTS isn't sending any signals to the ECU? Measuring with a multimeter perhaps, but I don't have any values to go after, I haven't dug into the manual yet but did a quick sweep in there and couldn't find anything on the harness side of things.

Johan
18-06-2018, 14:22
pointz

You can check the wiring colour to each plug by pulling the boot back then compare to the wiring diagram!

I got it all written down at home so can let you know colours but for now I have a gut feeling ecu coolant sensor is sky blue altho will confirm later.
18-06-2018, 14:26
pointz

Quote:

Originally Posted by pointz

You can check the wiring colour to each plug by pulling the boot back then compare to the wiring diagram!

I got it all written down at home so can let you know colours but for now I have a gut feeling ecu coolant sensor is sky blue altho will confirm later.

Coolant sensor is orange, blue and solid black

Air reg is black, yellow and solid black
18-06-2018, 15:21
h0ivik

Quote:

Originally Posted by pointz

Coolant sensor is orange, blue and solid black

Air reg is black, yellow and solid black

Alright, thanks pointz!

That confirms that I've plugged in the right one now, must have mixed them up whilst the car was in winter storage..

Air reg wires are fine, but do you by any chance know the colours of the wires going to the AAC?

I'll remember to check the wiring diagram the next time I'm wondering about wires! :D
18-06-2018, 15:26
pointz

Quote:

Originally Posted by h0ivik

Alright, thanks pointz!

That confirms that I've plugged in the right one now, must have mixed them up whilst the car was in winter storage..

Air reg wires are fine, but do you by any chance know the colours of the wires going to the AAC?

I'll remember to check the wiring diagram the next time I'm wondering about wires! :D

Sky blue and brown :thumbs:

All on the last pages of the EL Section of workshop manual
18-06-2018, 15:37
h0ivik

Quote:

Originally Posted by pointz

Sky blue and brown :thumbs:

All on the last pages of the EL Section of workshop manual

That was the one connected to the coolant sensor until I switched them around yesterday, glad to know everything is plugged in correctly now!

I did notice something when driving home from work today, on cold engine (not been started for 9 hours), it still is a little "lumpy" and a bit difficult to drive. But after 1 - 2 ish minutes it's running good. Doesn't happen when engine is warm, I tried shutting it down and starting it again on my way home, worked fine.

Could be the AAC unit, the unit itself is ok, but it doesn't respond at all when I plug it out/in.
Might be a wiring issue somewhere..

Any ideas, or do you think I'm on the right track?
21-06-2018, 13:59
kavapanger

have had exactly the same problem for last 1.5 years, runs rough and feels like someone applying brakes every time the car is restarted even when hot

problem occured after i changed my temp sensor so try different one, im just toooooo lazy to change it again and just keep my engine running when on a go
21-06-2018, 16:32
h0ivik

Quote:

Originally Posted by kavapanger

have had exactly the same problem for last 1.5 years, runs rough and feels like someone applying brakes every time the car is restarted even when hot

problem occured after i changed my temp sensor so try different one, im just toooooo lazy to change it again and just keep my engine running when on a go

It's definitely working better after connecting the correct plug to the temp sensor.. Made a huge difference, it only happens randomly when the engine is cold now, doesn't bother me too much tbh.

I did swap out my oem sensor last year, still have it laying around somewhere.. Might put that one in, just to see if there is a difference.

Sent from my celly via Tapatalk
29-06-2018, 12:16
h0ivik

Swapped out the sensor for the OEM one, ran like crap. So I'm just going to run with the other one that I have, since it runs perfect with that.

Runs pretty good when cold now as well, so it seems like the problem is solved..:D