R33 Coolant Temp Sensor

[95 GTS25T]

Hello all

Want some advice recently my 95 R33 GTs25t has been giving me starting issues, dosn't do it all the time

sometimes it takes 2 - 3 goes before it starts, sometimes it takes a long time to start and

then when it does start up the revs drop right down and it nearly stalls before revving back up to normal again

once its started it drives fine.

Iv'e been looking at a few things and was wondering if the coolant temp sensor

would cause this, I have noticed lately that after a 40min drive my cars temp gauge is still showing that its cold

the gauge does move up from the first stroke but it dosen't quite reach its normal operating temp by the guage,

which I think is wrong as the car would have been definetly warmed up after a 40 min run, I have been to various places

to check this starting issue and they hook it up to the scope and such and no errors come up at all, they find nothing wrong with it

and I have heard that the coolant temp sensor will not show up any errors, also another thing could it have anything to do with O2 sensor

as far as I know this has not been replaced and I know a lot of people replace this at 100,000kms the CAS has been checked and it seems fine

I'm taking it in tomorrow for its 130,000km service hopefully they find something and fix it

Just wanting to know what it could be so that when I take it in I can get them to check it.

Any help on this would be greatly appreciated.

[lachlanw]

the gauge on the dash and the ecu have their own temp sensor . does the heater still get hot as a mofo ? if not its most likely thermo stat

[blind_elk]

Is this a "hot start" issue, or a "cold start" issue, or both?

If the engine isn't getting up to normal temp, and also takes a long time to get up to temp (approx 5 minutes gentle driving should see the engine at normal temp), then it is possible the thermostat is jammed part open, and needs replacing.

To test the gauge is working correctly, set the key to IGN, disconnect the wire onto the (single-pin) temp sensor, and ground it out on the engine - the gauge should go full-scale if it is working correctly.

NOTHING TO DO WITH THE O2 SENSOR! It only works for cruise conditions.

[95 GTS25T]

I'm fairly sure its a hot start issue as when I start it first thing in the morning it starts up fine,

and when I start it to go home from work it starts up ok, it generally has the issue after I get home from work

I'll leave it for about half hour - hour then when I get in it to start it up to go out again it plays up,

and regarding the heater I don't reckon it gets as hot as much as it used to, so it might be the thermostat playing up

I'll have to check that out

thanks for the reply guys.

[blind_elk]

Well, according to the workshop manual, difficulty warm / hot starting could be related to the (ECU) temp sensor. Try disconnecting the sensor, see if it makes any difference. Check the resistance of the sensor. Check its output voltage.

Can also be a fuel pressure problem. Try clamping off the fuel return line, see what happens.