High fuel consumption

[arendal]

Now i solved my start problems by adjusting the TPS. Now the car starts every times... Great... But i still think it gets to much fuel, it smoke a litle, and the smoke smells like gasoline.... The car also uses a lot of fuel. Its only drive 5km/l. (20L/100KM)

I have testet the back o2 sensor, and the volt continuous goes between 0 and 0,9... So it must be okay i asume??

But i have some problems testing the front o2 sensor, i cant reach it. Is there another place i can do the measurement?? Or do i have to get it from the bottom of the car???

I have no fault codes, and the car is running smooth and nice...
New sparkplugs and air filter.


Some ideas???

[arendal]

In miles pr galon it would be, 12 MPG

[MX3-Life]

Jesus Christ that's like driving a H2... I feel sorry for you

[Newfie_dan]

check your coolant temp sensor resistance with the car at full runnign temp, it shoudl read between 1.9k ohms and 1.32k ohms. Mine was reading 362 ohms and I was burning a good bit of fuel above the normal amount. The front o2 sensor is best accessed from underneath the car.

[mikeinaus]

also wondering about this. my gas mileage is slightly better then yours but not by much. just got 250km to 33L of fuel. can o2 sensors go bad without giving a cel code?

[_-Night-Shade-_]

also wondering about this. my gas mileage is slightly better then yours but not by much. just got 250km to 33L of fuel. can o2 sensors go bad without giving a cel code?

Yes.

[arendal]

Now i check to front o2 censor, blue pin and gnd. It says -0,02 volt constant, and when i do the same thing on the back censor the volt continuous goes between 0 and 0,9. So i think that the front o2 censor must be dead?`

My coolant temp sensor resistance(if its is the one with green connector) works perfekt, with hot engine stands on 0,230 kohm.

[Newfie_dan]

there are 2 coolant temp sensors, a single wire one thats for the dash gauge and a 2 wire one right in front of it, warm the car up shut it down then unplug that plug and check the resistance across the 2 terminals.

[arendal]

My car has 3 coolant sensors. But thats the way i done it...

[jmdearras]

Now i check to front o2 censor, blue pin and gnd. It says -0,02 volt constant, and when i do the same thing on the back censor the volt continuous goes between 0 and 0,9. So i think that the front o2 censor must be dead?`

My coolant temp sensor resistance(if its is the one with green connector) works perfekt, with hot engine stands on 0,230 kohm.

Sounds like the sensor is bad. It is indicating a lean mixture, which would make the ECU add fuel trying to get it to 0,45 which is ideal. The other sensor seems good, the ECU is always seeking back and forth from lean to rich.

Jim

[RX8SE3P]

My car has 3 coolant sensors. But thats the way i done it...

You can't have three. You have one or two, all 1992-3 cars have two sensors, 1994 and onwards just have one. The other little one is just for your temp gauge in the car. It's not one that can affect performance

[arendal]

Yes i know one of the three is for temp gauge. And one for the fan...

[Newfie_dan]

My car has 3 coolant sensors. But thats the way i done it...

You can't have three. You have one or two, all 1992-3 cars have two sensors, 1994 and onwards just have one. The other little one is just for your temp gauge in the car. It's not one that can affect performance

Not true, mine is a 96 v6 obd2 and I have 2 coolant sensors, I have never heard tell of 3, there are 2 to my knowledge, 1 for the dash its a single wire sensor, and a 2 wire one for the ecu/ecm that is so the computer can read what the temp is and the ecm is what controls the fan being turned on and off.

[RX8SE3P]

My car has 3 coolant sensors. But thats the way i done it...

You can't have three. You have one or two, all 1992-3 cars have two sensors, 1994 and onwards just have one. The other little one is just for your temp gauge in the car. It's not one that can affect performance

Not true, mine is a 96 v6 obd2 and I have 2 coolant sensors, I have never heard tell of 3, there are 2 to my knowledge, 1 for the dash its a single wire sensor, and a 2 wire one for the ecu/ecm that is so the computer can read what the temp is and the ecm is what controls the fan being turned on and off.

Yes we are in agreement on that.

So if either of the coolant temp sensors going to the ECU go bad they will make the car run rich?

[Newfie_dan]

it will have an impact on the fuel/air mix since the car will think the car is either overheated or cold and that influences the fuel air mix, it uses the o2 sensors, intake air temp, air flow (via vam) and coolant temp sensors to determine the correct air fuel mix, if any of them are out then yes the car can burn rich. Now these are just the electrical sides of it, of course mechanical condition of the car, elevation, and driving styles also heavily influence fuel economy. My car being an obd2 based v6 is basically the same as your obd1 model the only difference being that the obd2 computer reads things a little better. It still did not tell me that my coolant temp sensor was out of whack, it will usually ony throw codes when it loses contact with a sensor or a sensor fails.