Running issues

[alexfalk]

Now I have finally driven the car after a complete rebuild. However it is acting up.

From like 2krpm it feels like it should and starts to pull. But when it reaches up to 3-4krpm it doesn´t go any further and starts to hesitate a little.

Everything is brand new eccept the plugs. The timing is 15 btdc and everything else seems in order according to the consult. I noticed that the 02 sensor where acting up. its flickering up and down. Is that normal?

Any ideas?

 

[Matt_S]

Coilpacks. :thumbs:

Its one of the few things the ECU cant diagnose either :wack:

 

[alexfalk]

It´s worth a try. I will swap them for my friends today and see if it works. What is it that breakes in them and what is it that´s causing it? It seems like a lot of people have problems with them...

 

[JEZ 8553]

I believe its due to heat buildup which is why the normal coil to fail is the one at the back of the engine where its hottest. If you have a tubular manifold this will probably be helping contribute to the problem due to raised under bonnet temps. You could try removing the the coil pack cover to allow better air circulation around the coils or get an aftermarket vented cover.

 

[Matt_S]

TBH the Nissan ones last a LOT longer than some! Ive seen Renault and VW ones fail at 60k/2 years old.
To have one to fail on one of our 88 year old (+) cars (assuming its original) is pretty good going imho :thumbs:

 

[Matt_S]

Failing that, check the cam timing (the sprockets themselves).

 

[alexfalk]

I installed a set of DI coils and swapped the plugs just now.
But the problem remaines. If I put my foot down when it starts to hesitate it starts to backfire.

I´m experiencing that the manifold is a little hot and by the looks of the plugs I´m guessing that it´s running lean.






The thing is that I have fitted higher capacity fuel pump and 650cc injectors. So I can´t imagine that it would be leaning out. However the new fuelfilter that I installed was from a different car make. Maby this one is not letting enough fuel through?

I have been thinking about the cams aswell. I´m sure they are mated to the marks on the chain but the one in the bottom could have jumped when I installed the cams. Are there enough play between the valves and pistons to allow the camsprocket to be slightly off target?

 

[Matt_S]

Did you put the filter in the right way (flow towards engine).

If youre worried it might be the o2 sensor, disconnect it.

What ECU you running?

 

[alexfalk]

Yep the filter is mounted right. Will pick up a z32 filter today.
It´s a remapped tomei CPU but I have a PFC that will be installed in time for the mapping.

 

[ichi-go]

If you are testing this in WOT, then it is not the O2 sensor's fault as the ecu neglects any readings from the o2 sensor in WOT mode.

 

[gunner93]

It may worth your while to unplug the O2 sensor harness and run without it? I had same problems as well and mine was the O2 sensor.

 

[alexfalk]

I have been thinking about this all day and come to the conclusion that it have to be the timing chain that sits a tad off. I´m running without the mechanical fan and the temp is rising fast wich is od because it´s around 0 degrees here right now. Will check this tomorrow. Just hoping that this is it!

 

[alexfalk]

Problem solved. It turns out that you can not use the workshop manual to adjust the timing

I tried another way and then the timing light read 5 degrees btdc instead of 15.

I was pretty amazed by the bottom end power it produced without propper tuning and 0,5 bar of boost

 

[meddler]

please enlighten us. What other way did you try?

 

[Yakozan]

Strange. The workshop manual is ADM specific. But most stuff should be the same. Maybe this is one of the things that differ for some odd reason

 

[Matt_S]

WTF?

Thats bollocks! THe S14 manual can be used to set the cam timing up and adjust the ignition timing! Its an SR20 not a NASA rocket! :wack:

 

[alexfalk]

The problem was that the loop used for the timing light is worthless. I put an ignition cable between the plug and the coil and used it for the timinglight. That and the tps unplugged showed a completely different reading. Very strange. But it obviesly works.

 

[Matt_S]

Ah! Yeh, you need pretty specialist gear to use the induction loop wire thingy. I always just do what you ended up doing and put a plug lead between the plug and No1 coilpack with the timing guns clamp.

 

[als_jordan]

Just to put my two pence in... Yes that's normal... the o2 sensor sample every few seconds and the ECU continuously moves from lean to rich and back again.. If it is stationary or only moving slowly then it is knackered!

I noticed that the 02 sensor where acting up. its flickering up and down. Is that normal?

Any ideas?