Hello All,

I have searched and im not sure what to try next.... My car barely warms up,
When it does it will only get a little over 1/4 on the gauge, not near the 1/2 mark.

I get heat when it warms up to that mark and it will only warm up usually if its warm
outside or I let it warm up in the driveway.

This would lead me to believe THERMOSTAT, So I purchased a new one from the
dealer replaced it and still the same thing.

My fuel mileage is also pretty bad and I feel it is because of this issue. I get around
200MPG CITY or so to a full tank my commute to work is local so no HWY driving really
I do however get on the gas alot but I should still get more than that I use too.

Items Replaced already:
Air Filter
Timing Set to 17
Cat Converter
Thermostat + Coolant Flush
EGR Cleaned
Plugs
Cap / Rover
Fuel Filter
Throttle Body

Could this be one of the 2 coolant temp sensors? My fans work when needed but
the car will not warm up correctly.

Any help would be greatly apreciated so I dont waste money and time on parts
that is not needed I do have an FSM to assist in the work just not sure what it could be.

Thanks,

I get around 200MPG CITY
Wow! That's really good!
j/k ;)

1 CTS is for gauge cluster only
The other is the engine coolant temp sensor that the ECU reads - that's the only one that will affect how it runs.
If the engine CTS is bad, you would have a bad cold idle also.

First I would go to a parts store that checks error codes for free - Autozone and Checker both do I think.

I'd check for vacuum leaks, fuel pressure regulator, MAF ground and oxygen sensor.

Could a bad O2 Sensor affect engine warm up? I know it could affect the MPG.

Vacuum leaks I can double check I tried looking for any in the obvious places.

MAF is reground already, what could I check with the fuel pressure regulator?

The cold idle does go high at times to like 1500RPM once it warms up a tad its pretty stead at 900rpm or so.

The fans appear to work properly and performance although probaly could be better with the perfect mixture still feels pretty good.

The cold idle does go high at times to like 1500RPM once it warms up a tad its pretty stead at 900rpm or so.

The fans appear to work properly and performance although probaly could be better with the perfect mixture still feels pretty good.

Bad ECTS should cause the fans to be on all the time, so probably not the issue with yours.

Bad O2 wouldn't affect warm up time since ECU ignores it until warm, but could affect fuel economy.

Fuel pressure regulator - either swap it with a known good one, or put a fuel pressure gauge on to see what the fuel pressure is. First check vacuum line to fuel pressure gauge, leak would affect the fuel pressure. Check fuel lines for leaks, although you probably would have noticed that already.

Check the connector for the gauge temp sensor.

Get the error codes checked!

FSM lists diagnostic procedures in section EF/EC.

Know anyone near you with a NisDataScan or something like that?

I do not know anyone with a NisDataScan but I do have the FSM so I can check for codes.

My fans are not on all the time so Im assuming I could have 1 bad sensor the one for the gauge but not the other. ( if this can affect warm/up - idle nice )

I will check fuel lines + fuel pressure what should the stock fuel pressure read?

You should consider replacing the radiator cap (if you don't know how old it is), and adjust the throttle position sensor - or replace it if it won't go into an appropriate range. Get your base idle and timing adjusted appropriately as well.

I'm going for the gauge temp sensor being bad. If the gauge shows cool, but you have heat, then nothing is really wrong. 200 miles on a tank is somewhat normal for all city driving and some spirited romps.

I'm going for the gauge temp sensor being bad. If the gauge shows cool, but you have heat, then nothing is really wrong. 200 miles on a tank is somewhat normal for all city driving and some spirited romps.

Eric,

Well i only have heat when it sits still for a while and at that point it will go up a little over 1/4 never to 1/2.

Once I start driving a decent amount the temp gauge moves down towards cold. Now that its getting warm it stays up a bit longer but during the winter it would almost never warm up unless it was parked.

Screams thermostat but thats brand new and the old one looked fine.


PS.. 200ish MPG is normal or about normal for city only and many spirited romps ?

You should consider replacing the radiator cap (if you don't know how old it is), and adjust the throttle position sensor - or replace it if it won't go into an appropriate range. Get your base idle and timing adjusted appropriately as well.

TPS and Timing have been properly adjusted last week ( set base timing to 17 degrees )

Will look into replacing the radiator cap what are signs of a bad radiator cap?

Eric,

Well i only have heat when it sits still for a while and at that point it will go up a little over 1/4 never to 1/2.

Once I start driving a decent amount the temp gauge moves down towards cold. Now that its getting warm it stays up a bit longer but during the winter it would almost never warm up unless it was parked.

Screams thermostat but thats brand new and the old one looked fine.


PS.. 200ish MPG is normal or about normal for city only and many spirited romps ?


Was it an OE themostat, or an auto parts special? I had issues with a new auto store part, and one from Nissan fixed it for me.

Only OEM for me :) The one I pulled out said NISSAN on it too just not sure how old it was. Driving me crazy why the car has a problem warming up totally

Daryl,

Get yourself a Blazt consult cable, and you won't be guessing as to what your temp sensor is doing. You've been playing with these cars too long to not already own one. ;)

USB cable $68 (http://www.blazt.biz/order/order.php)

Order from one of the US distributors (http://www.blazt.biz/contact/messageus.php).

You can purchase the software from them as well, or use Calumsult or the freeware version of ConzultSX (http://300zx-twinturbo.com/conzult/software/free_conzult.exe), both will give you everything you need to read all the sensors in your car as well as put the ecu into timing mode, and some other handy tests.

C

Thanks Chris, I will be purchasing this cable when I get paid. Seems to take alot of guess work out of problems like this when you can see what the sensor is doing in real-time.

Still have no clue whats going on with it not warming up. Whens the next NJ meet i gotta pull this ABS OUT!!!!

Whens the next NJ meet i gotta pull this ABS OUT!!!!Check with Mark. He mentioned putting something together in the next month or two.

C