S50 Issues

[Steven]

So I got my swap running but I've run into a few problems.
1. The temp gauge doesn't work. I start up the car and it goes up to the first line indicating it's working and waiting for the engine to warm up, but no matter how long i run it (not too long because I don't want to overheat it by accident)it just doesn't budge. It has the brown temp sensor on it with the blue one for the ECU. I'm wondering if because my car is a 318 does it need an m42 temp sensor?
2. The tach isn't working properly. It'll show presumably the right numbers when it's idling, but as soon as you go to rev it, the needle just shoots up and goes way past the 7k mark. It's not in sync with the engine at all it seems like.
3. It doesn't idle all too well. It'll be idling and just go up and down in revs. It'll seem like it wants to cut out then the revs just magically go back up. Also sounds like it has a slight misfire when the revs go down? But I could be mistaken.

Thanks for your help!

[mitchlevy7]

for the tach you need the right 6 cylinder coding plug. I believe one from an m20 car works.

maybe your thermostat is stuck open and not getting to temp. I don't believe there's a difference between m42 and m20 cluster coolant sensors. Are you using an adapter or is it right in the head? The sensor grounds to the engine and is only one prong.

for your idle, make sure your ICV is good and clean. After you clean it or replace it, make sure you do an ecu reset by disconnecting the battery for at least 30 seconds.

[rzerob]

You can test that your coolant temp sensor is bad buy grounding out the wire to the sensor and watching the gauge. If the needle goes all the way up then your gauge and wiring to the gauge is fine, sensor is probably bad.

[Steven]

for the tach you need the right 6 cylinder coding plug. I believe one from an m20 car works.

maybe your thermostat is stuck open and not getting to temp. I don't believe there's a difference between m42 and m20 cluster coolant sensors. Are you using an adapter or is it right in the head? The sensor grounds to the engine and is only one prong.

for your idle, make sure your ICV is good and clean. After you clean it or replace it, make sure you do an ecu reset by disconnecting the battery for at least 30 seconds.

So much info! Thanks!
Maybe my thermostat is open... the spring foes to the inside correct? I'll check orientation tomorrow. It is right in the head so should be grounded
I'll check and make sure the ICV is all clean

You can test that your coolant temp sensor is bad buy grounding out the wire to the sensor and watching the gauge. If the needle goes all the way up then your gauge and wiring to the gauge is fine, sensor is probably bad.

Okay I'll try that if the thermostat doesn't change anything.

[mtech325]

+1 for checking/cleaning the ICV.

The reason I say that is because I had a very similar problem when I put the s52 into my e36 (I know bear with me!). The car was idling at 1500 rpm and sometimes the idle would buck. Once everything was checked and cleaned, I reset the ECU by undoing the battery cable and everything has been running smoothly since. Sounds like you're pretty close to getting everything ironed out :)

--Joey

[Steven]

Checked the temp sensor by grounding it. Looks like it's bad but wont know until I get another to try. Anything on the RPM issue?

[Pocket Chant]

Anything on the RPM issue?

I mean, do you have the correct coding plug?

[rzerob]

http://www.r3vlimited.com/board/showthread.php?t=211454

[Steven]

I mean, do you have the correct coding plug?

http://www.r3vlimited.com/board/showthread.php?t=211454

lol I actually didn't know about this. Sorry and thanks.