# Nissan EFB13 Messed up



## adinindu (Dec 6, 2013)

Model : Nissan EFB13
Engine : GA15DS with ECC
Note : Without E.G.R Model

I am from Sri Lanka and have a EFB13 since 3 months. In here its suppose to do 10-12KM/L in city limits and 12-14KM/L outstation. However mine did only 4-5KM/L in city and 7-8KM/L in outstation. Also my spark plugs were fouled too. So i did little research and figured it might be carburetor problem and gave it to a guy for repair. He put a repair kit and try to fix it few times. Every time he fixed it up, car runs very smooth and even i could see water coming out of exhaust. However the fuel consumption stayed the same and spark plugs too. Also i could see a little bit of black smoke coming out of exhaust time to time. Since the repair guy claimed carb might have been messed up by previous owners and good to replace it, i replaced it with a new one. Then i got a little improvement on fuel(5-6KM/L City) and power. 

Even though there were no black smoke i could see lot of carbon inside exhaust pipe even after i cleaned it completely. So i went to a emission testing center and put it to a test, they were flattered - my idle CO level was 10-11(no black smoke) and it was suppose to be under 0.4.

Then i found a similar Service manual to my car and after reading around 2500 pages i picked few things -- check the ECU. The ECU light is completely off but manual says it needs to blink. So i replace ECU. 

As soon as i plugged new ECU i felt a difference. Engine was quieter, Steady RPM and more power too.... and no intermittent black smoke either. I was happy - thought it solved. But after 1 week(200KM City driving) fuel economy was same(5-6KM/L) and it lasted only for 2 weeks again i got intermittent black smoke and fouled spark plugs...

I am out of ideas, any suggestion guys....

I really appreciate it...


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## b13er (Apr 7, 2010)

The fact that the new one made your car run perfect, and now it's crappy again, makes me think that now your ecu is fried again.

Did you check the ECU again? If it's burned out again, sounds like you have a short somewhere.


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## adinindu (Dec 6, 2013)

b13er said:


> The fact that the new one made your car run perfect, and now it's crappy again, makes me think that now your ecu is fried again.
> 
> Did you check the ECU again? If it's burned out again, sounds like you have a short somewhere.


Last week i spent 2-3 days checking Wiring for short circuit. But then i found my Temp sensor not working and the signals from O2 sensor is not getting into ECU. 

The strange thing is when the engine is cool and idle, i can see water coming out from exhaust and 02 sensor voltage is about 0.4-0.5 but when engine heated i can smell gasoline and o2 reading is 0.7-0.9

Is there a way that i could check the ECU before replacing it?

Both ECU doesn't have visual burnt signs.


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## smj999smj (Jan 1, 2006)

Only way I know of testing an ECU is to send it out to a place the repairs them and have them test it. Otherwise, it's usually a process of elimination after following the diagnostic procedure in the service manual for the specific problem(s)...assuming there is no obvious physical damage to the unit (burnt circuitboard, corrosion, etc.).


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## adinindu (Dec 6, 2013)

I check my car's entire wire harness for any damages or malfunctions according to the service manual. I couldn't find anything. Also i repaired the power distributor which was covered with leaked oil and faulty spark plug wires -- and also put new spark plugs.

Now the car runs very smoothly and no black smoke. But fuel consumption stays same. 5-6KM/L in city.
So i tested the ex-haust gas. When car is idling CO level is 0.45-0.55. However when i accelerate, CO level raised up to 8-9 till 3000RPM and 5-6 CO level beyond 3000RPM.

Any ideas?


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## smj999smj (Jan 1, 2006)

You might want to inspect or replace the oxygen sensor and also test the fuel pressure to make sure it's within specs. If it's an electronic controlled carb, then you'll also want to make sure the engine coolant temp sensor is working properly and the engine is warming up to normal operating temperature (you might have a stuck open thermostat causing the engine to run rich).


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## adinindu (Dec 6, 2013)

smj999smj said:


> You might want to inspect or replace the oxygen sensor and also test the fuel pressure to make sure it's within specs. If it's an electronic controlled carb, then you'll also want to make sure the engine coolant temp sensor is working properly and the engine is warming up to normal operating temperature (you might have a stuck open thermostat causing the engine to run rich).


Yes, Its an electronic controlled carb. I have replaced the oxygen sensor and the thermostat valve as previous owner removed it. Engine is warming up to 40-50% according to temperature gauge. I guess only thing remains here is the coolant temperature sensor and i will post here the results when i tested it. Thank you for the idea...


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## Josef Strauss (Feb 25, 2014)

I am from Sri Lanka and have a EFB13 since 3 months. In here its suppose to do 10-12KM/L in city limits and 12-14KM/L outstation. However mine did only 4-5KM/L in city and 7-8KM/L in outstation.


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## adinindu (Dec 6, 2013)

Josef Strauss said:


> I am from Sri Lanka and have a EFB13 since 3 months. In here its suppose to do 10-12KM/L in city limits and 12-14KM/L outstation. However mine did only 4-5KM/L in city and 7-8KM/L in outstation.


Hey...Exactly the error mine had. I was able to resore the fuel efficiency by doing folowing.

1. Replaced O2 and Temperature Sensor
2. Corrected connections errors between ECU and the Carb

Check your PM and call me.


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