Engine only runs with throttle position sensor disconnedted??

[Mark Le Rouret]

never worked on a k12 tbh mark, i think its pot luck with generic readers or apps
maybe the cts is working ok but not communicating with the ecu ?

I could ask my local garage if they have a pro reader. It won't be a Consult but it might come up with something.

When I disconnect the Temp Sensor I get the corresponding fault code so that would suggest the connection is good?

 

[Mark Le Rouret]

I drilled a hole in the top of the airbox so I can spray petrol in easily every morning.
It's a workaround that might go on for a while I fear....
This time of year, once its started in the morning its good all day.

 

[frank]

I could ask my local garage if they have a pro reader. It won't be a Consult but it might come up with something.

When I disconnect the Temp Sensor I get the corresponding fault code so that would suggest the connection is good?

canbus does some weird things eh

 

[Mark Le Rouret]

Local garage has pro Bosch diagnostic system. Came up with no faults at all.
Even my basic Autolink shows an amber (pending) fault.

Anybody have any ideas at all how I can get a Consult 2 type diagnosis without having to spend £150+?

 

[Sparky2018]

How do you get consult 2. I'm also trying to figure out how to get hold of this.
So far not finding anything at an affordable price but will continue the search.
If I happen to find something will post it up on my blog.

Sent from my ASUS_T00P using Micra Sports Club mobile app

 

[frank]

ask these guys, used to be very helpful, or datascan app maybe ?

Consult information

This is all about consult for Nissans with an emphasis on consult for the Almera N16 but will still be very useful for other models. This is also part of a series of threads I've made about the SAT NAV setup in the Almera and it's links to the immobilizer (NATS). All of this information is...

www.almeraownersclub.com

 

[Sparky2018]

Got the NDS II lite with intentions of testing if I can connect with the Wi-Fi scan tool.
Then if that fails would get a cable to use via laptop.
Maybe the full version of this will be better choice if compatible with my device then would be okay to upgrade to that version.
I am yet to test it out but am really interested to find out more about what if any extra options/limitations are present via the app.


Sent from my ASUS_T00P using Micra Sports Club mobile app

 

[plmval]

Car still runs great all day once started in the morning.
This still points to a "cold start enrichment" problem...
Any other ideas if its not the temp sensor?

May I suggest that you cross check the water temp sensor resistance readings @ the ECU end of the temp sensors wire connections at the ECU?

Trace & disconnect the temp sensor wire connections at the ECU in order to test that the temp sensors resistance at the end of the wires is almost identical to that of the sensor?

Give the values found?

Resistance in the wire/terminal lugs/connectors may produce a signficant misreading at the ECU at 20 c @ 2.5 Ohm K or less starting temperatures?

Quote; “ I am waiting for the new sensor to arrive, so removed the old sensor and tested it against these figures I found on this forum:

The ecu coolant sensor should read-
0.25 ohm @ 90c
0.85 ohm @50c
2.5 ohm @20c

My sensor gives:
0.3 k ohms @ 85 c
2.4 k ohms @ 24 c”

Happy fault finding

 

[Mark Le Rouret]

May I suggest that you cross check the water temp sensor resistance readings @ the ECU end of the temp sensors wire connections at the ECU?

Trace & disconnect the temp sensor wire connections at the ECU in order to test that the temp sensors resistance at the end of the wires is almost identical to that of the sensor?

Give the values found?

Resistance in the wire/terminal lugs/connectors may produce a signficant misreading at the ECU at 20 c @ 2.5 Ohm K or less starting temperatures?

Quote; “ I am waiting for the new sensor to arrive, so removed the old sensor and tested it against these figures I found on this forum:

The ecu coolant sensor should read-
0.25 ohm @ 90c
0.85 ohm @50c
2.5 ohm @20c

My sensor gives:
0.3 k ohms @ 85 c
2.4 k ohms @ 24 c”

Happy fault finding

Hi,
I have come back to this problem now I have more time.
Meantime, I have been using the 'fuel on filter' workaround just to cold start in the mornings and its been fine.

I have noticed in the live data on my OBD2 reader has the following:
IAT(°C) 29 (Inlet Air Temp)
ECT(°C) 27 (Engine Coolant Temp)
These values are entirely consistant for a cold engine, with the outside air temperature of 28° at the time. Also these values increase as the engine warms up during running.

From this I assume the temperature sensers are working and the wiring is good.

On another tack, another thing that changes fuel is Fuel Trims. Frank aludes to this...

that short term fuel trim does,nt look right mark
need a copy nissan consult really

Looking more closely at the Short Term and Long Term fuel trims...
SHRTFT1(%) 1.6 (Short term trim goes up and down under 5 at idle. Ramps up when I rev the engine. Seems normal from what I understand)

When I disconnect the o2 sensor (before the cat) short trim goes to 0 as you would expect.
O2S11(V) 0.1 (I assume this is o2 sensor (1) and goes up and down between 0.1 and 0.8. This is what controls the Short term trim).

LONGFT(%) -0.8 (long term trim is average calculated from short term I understand)


It's these other trim values I dont get....

SHRTFT11(%) 0.8 (Looks same as SHRTFT1(%) but its on another screen so cant see them together. goes up and down in similar range.)
O2S12(V) 0.3 (I assume this is o2 sensor (2) and is static around at 0.3 even with cold engine. This is the lambda sensor after the cat I think.)
SHRTFT12(%) 99.2 (This never changes, even with cold engine and both o2 sensors disconnected)

Writing this down, logically it looks like o2 sensor 2 might be controlling this other Short term trim, but is not working.
From what I have read, this shouldn't prevent the engine from starting cold, should it?

Any thoughts or ideas greatfully received.

Mark

 

[Garp242]

I drilled a hole in the top of the airbox so I can spray petrol in easily every morning.
It's a workaround that might go on for a while I fear....
This time of year, once its started in the morning its good all day.
View attachment 70545

Hi Mark
I have a very similar problem with my K12 Micra that you had with yours. It just refuses to start when the engine is cold. I changed the Coolant Temp Sensor, but it made no difference. So I followed your tip of spraying petrol in the Air Filter, and I'm happy to say It Worked !! Once the Engine is up to working temperature, the car drives fine and starting is no problem - until it gets cold again (next morning).
My question is - did you ever find out what was causing the problem with yours ??

 

[Mark Le Rouret]

Hi,

I'm sorry to say I never did. It remains a mystery.
If you look back thru this thread you'll see II tried everything and spent months on it.
Two garages, including a Nissan dealer couldn't fix it and gave up.

I did use the petrol workaround for 2 months but eventually it got worse and it would start but would fail when out on a run.
Coincidentally I just bought a replacement car yesterday, so the old K12 is destined for the breaker.
It grieves me because I had it from new and it is still a good car in every other respect.
I still think it's a niggling little fault that is probably easy to fix, if only you could diagnose it.

Please do let me know if you fix yours.

Cheers,
Mark