Hi guys,

 

I've just been to see a poorly Zed of a colleage of mine and need to bounce some ideas off you guys to see if I'm heading in the right direction.

 

These are the symptoms:

 

1. Car is very difficult to start

2. Idles EXTREMELY rough and stalls after a while (if you don't keep your foot on the accellerator)

3. ConZult ECU codes results - 13 (Coolant system) & 34 (Detonation sensor)

4. ConZult sensor reading - engine temp is very slow to climb to operating temp (took about 1/2 hour at 1500rpm to climb to 68C)

5. under light load (while stationary) there is obvious detonation (but not all the time)

 

The ECU code 34 is not a worry as (a)the connector is buggered and (b) the car is audibly detting.

 

I'm not sure what the matter is with the coolant sensory system as the actual temp sensor is new (no corrosion) and when disconnected it engages the aux fan. But it is very clearly giving the wrong signal to the ECU.

 

Another thing that the ConZult scan revealed was that the entire left bank of the car isn't firing (!) Plus intermittently, cylinder 1 isn't firing either (no wonder the car stalls)

 

My initial thoughts are that (a) there is a problem with the wiring loom and (b) the PTU could be buggered.

 

I will swap the PTU for a know good one and see what happens but I need some thoughts on any other causes of these problems. The car is pretty much undriveable and the problems manifested themselves over a period of two days.

 

Any thoughts are much appreciated.

 

Cheers!

 

Danny

Danny, we had similar problems with a car overhere and it turned out to be the big ECU connector itself had come loose somehow.

 

If you erase the error codes, does the code 13 come back ? if so there's probably something wrong with the sensor, even when it's new.

It could be they used one from another Nissan, since different (Nissan) tempsensors fit in our cars, but obviously don't give a correct reading.

 

the PTU swap sounds like a good plan..also check the injector and coil connectors.

 

-Eric

Water pump???

 

The temperature may also not be rising due to the fact that the engine is only running on a few cylinders so not much heat is generated.

 

Have you checked the fuel pressure??? Difficult starting may suggest a worn fuel pump. This could also possibly explain the rough running, dropped cylinders and detting too.

 

As Eric said, check the ECU connector too. As I've said b4 - just because a sensor is new doesn't mean it isn't faulty - have you checked its resistance at known temperatures??? To be honest though, if the fan comes on when you disconnect it, then the sensor is at least giving a reading. Have you reset the ecu b4 checking the codes again? The code 13 could be an old one.

 

First of all, I'd check the injector connectors, fuel pressure and all the obvious other connections - PTU, Coilpacks, CAS....

 

In fact... that gives me another thought - if the CAS connectors are dirty, the injectors and coil packs won't fire, and if the ECU doesn't recieve the revolution information from the CAS, it turns the fuel pump off...

 

So new order:-

 

Check the CAS connection

Check the injector connections plus any others

Reset the ECU - just disconnect the battery (as you should anyway) while you are checking the connections..

Check the fuel pressure

 

Let us know how you get on...

 

CheerZ,

 

Andy

Andy, Eric - thanks very much for your feedback and thoughts. I hadn't thought of checking the ECU connector or the CAS connectors so will give that a once over when I'm next at the car. I did clear the ECU and the first start only produced code 34. Upon further starts code 13 came back as well.

 

This is what this forum is all about - putting our heads together to help each other. Thanks guys!

 

Cheers,

 

Danny