Running rich? Temp sensor maybe?

[GTU89]

Anyone have any ideas on what to do to fix it? The IAC and PCV valve were replaced, I think that it is the Temp sensor/coolant temp sensor

I'm getting terrible MPG too presumbly because of it running rich (the tranny slipping does not help though lol) around 8-12 city ( ) and 15-19 highway (@ 50-55mph). Its definantly running rich though, it smells like it.

So, should I go for the temp sensor or what?

And is there a difference between temp sensor and coolant temp sensor?
So far its been seafoamed, and had the IAC and PCV valve replaced.

Thanks

[Money pit Beretta]

My guess is that you changed the O2?

[Carson21R]

do you have a ses? is your idle weird? like idle at 1500-1600 like a cold start when its warmed up?
otherwise, if its been a long time or you've never changed the o2 replace that.

[GTU89]

No SES, idle was strange but a new IAC, PCV valve and Idle re-learn fixed that.
I've only had the car since like mid September so I have not replaced the o2 sensor.

So I should go for the o2 sensor? Will that be effected by the fact that the cat is punched out?

[Money pit Beretta]

No the O2 is before the cat. It's near the firewall.

[GTU89]

Okay, just to make sure. Its most likely the o2 and not the temp sensor? Only because money is a bit tight right now and I need to get the right one because the gas mileage is really terrible and the car shouldn't run so rich.

[Money pit Beretta]

Most of the time it's the O2 if the car has over 80k. I really don't know for sure man.
But it's an 89, so my guess the O2 is overdue anyway.

[pghturbo88]

Thermostat stuck open not allowing the engine to fully warm up and not go into closed loop? Happened to me once and MPGs were terrible.

[GTU89]

Okay, so far I've replaced the IAC, PCV and temp sensor (not sure if im missing anything else) and its still rich, guess I should've went with what you guys said?

There is grey smoke that smells like gas and it seems to backfire a bit when revved. o2?

[Money pit Beretta]

Is it missing? No codes right? Do the O2 later, you have a bigger problem.
Grey smoke like burning oil? A backfire is bad timing. How many miles are on this car?

[GTU89]

No, like a whitish-grey that smells like gasoline, sorry should've described better.

Its not burning oil, not leaking anything, not missing, no codes and by backfire I meant a popping sound, not a loud one but slightly noticeable. Again I should've described that better too lol. The motor runs really strong, its just running rich. it has like 176k or around that. The o2 is like the only sensor I can think of that would cause it to run rich. Like I said though, the motor does run really strong.

I'm guessing that the previous owners did almost zero maintenance, so far everything I've changed look like it was or could be original, the temp sensor (for the computer, not the gauge) broke in half when I took it off.

[3X00-Modified]

The o2 is not the only sensor that will make it run rich... as the topic stated, the coolant temp sensor will also do that. Mixture will be very rich till the car reaches operating temp and if the sensor is reading -40 like they do when they go bad then you will always be running overly rich.

Which temp sensor did you replace? Unless you have a digi dash there should be two of them. If you replaced the one by the thermostat then you have two choices now... Do the O2, or pull and have your injectors cleaned and checked for a stuck open one. That's one other possibility.

[DTMAce]

Most of the time it's the O2 if the car has over 80k. I really don't know for sure man.
But it's an 89, so my guess the O2 is overdue anyway.

Sorry I had to laugh at that comment. lol

Only because I still have the original O2 sensor on the Z. Along with every other sensor on the engine. I wasn't aware of a life expectancy...
/offtopic

Sounds like you guys have this one pinned down though. Temp or O2 sensor would be my guess as well unless something is really screwed up like injectors or similar.

[GTU89]

Well, as stated before, I already changed the temp/coolant sensor. So its o2 or injector cleaning/replacement?

[woody90gtz]

If you change the o2 get a Denso from RockAuto, not a POS Bosch.