Bad misfire under load

[wurlycorner]

don't know to all your questions above except one, I'm afraid (not studied the knock sensor on an H22 - although I can tell you exactly where it is on a M25/662...)
The answer as to whether it could affect the timing 'on the fly' though, is definitely yes - that is the sensors sole purpose! It listens for 'knock' (pre-ignition) and if it is detected, then the ECU retards the igntion, until the 'knock' goes away.

[ek9sid]

I'm sure the knock sensor is located just under the inlet manifold...unless I'm wrong

[hoppi05]

Thanks buddy, does anyone know how to test a knock sensor and is it worth getting a replacement one before swapping the dizzy

[wurlycorner]

First place to look would be in the service manual?

I do think more than just testing the sensor 'static' through, the wiring etc to it needs to be checked. With all the work that's gone into the looms as a result of engine swap, it could be an intermittent break, picking up stray 'noise' from something else etc.

Ps well done for sticking with all this, you've certainly not had it easy!

[hoppi05]

Haha cheers yes the loom doesn't get touched much just certain wires extended to fit to the differing sensor location I will remove intake tonight and have a butchers at it and get the multimeter out

Cheers again

[Merlin]

If the knock sensor is faulty it will give a code if it is connected to a JDM ECU. UK 4th gens do not have a knock sensor so the UK ECU will not be looking for one.

What was the guy doing with a laptop? What did he plug it into?

What was the base timing set to? ie with the service connector shorted?

[indigolemon]

What was the guy doing with a laptop? What did he plug it into?

Yeah, I wondered this too

[hoppi05]

Hiya guys he used his diagnostic box connected via the 3 pin point near the ecu this read the ecu and displayed all the engine telemetry etc plug old and new code etc.

This is a 92 jdm engine and ecu, the timing isn't set as it was moving under load no matter how we set the dizzy when set to some marks on the dizzy casing it was out at 30° I believe but when we drive this dropped to 0 and even a minus?

[Merlin]

Hiya guys he used his diagnostic box connected via the 3 pin point near the ecu this read the ecu and displayed all the engine telemetry etc plug old and new code etc.

Pluged in to what bit? directly into the ECU (piggy backing off the loom) or off the diagnostic plug or service plug?

Timing is meant to move under load. The ECU uses the base timing to calculate how to advance the timing as RPM builds. I do not see how anything can be achieved unless base timing at idle is properly set.

I am hypothesising here with my limited understanding of ignition timing and engine tuning, say for example your base timing is too far advanced and the ECU detects knocking (you have a JDM engine that has a knock sensor), would the ECU not try and retard the spark? Hence why the guy was seeing such a variance on ECU controlled timing?

IMO I would set base timing to 15 degrees before top dead center and go from there.

Also you are using super unleaded 97 RON fuel yeah?

[wurlycorner]

say for example your base timing is too far advanced and the ECU detects knocking (you have a JDM engine that has a knock sensor), would the ECU not try and retard the spark? Hence why the guy was seeing such a variance on ECU controlled timing?

Yep that's wot I said! :

Also you are using super unleaded 97 RON fuel yeah?

I did wonder about fuel as another possibility, but I've always run 95 RON in ludes (H22A2 or H22A) with absolutely no problems at all, so that shouldn't be the deciding factor here...