Cylinder 5 problems - Opinions please on what to check next

[hadtstec]

Hello everyone, I have a Tuscan MK1 with a 4.0L Speed six and cylinder number 5 is not happy.
When idling, I can feel with my hand over the passenger side exhaust that the exhaust is not steady like the other side.
I also used a temperature gun to measure the temperature of the manifold right by each cylinder and cylinder 5 is about 100 degrees cooler.
I pulled all the plugs and they were all good, apart from cylinder 5 which was brown.

My problem is that I've done all of the following, but the issue persists and I need advise on what to check next.
(These are all brand new quality parts)
- Replaced Spark plugs
- Replaced HT Leads
- Replaced Coilpack
- Swapped Injectors (1 and 5) and confirmed that the issue is still with Cylinder 5.
- Checked the wireing from the Engine bay harness plug to all Injectors and I have continuity for all.

What else is there to check?
Is this a common issue?

I assume that the next step is to check the wires from the ECU to the Injectors, but I am confused as to why I have continuity accross both terminals of the Injectors from the Engine Harness.

I have looked at the TVR Wiring diagram, but does someone have an ECU Pinout so I can check the fault from there?


Many thanks for any suggestions

Edited by hadtstec on Tuesday 28th July 18:19

[Modrich]

MBE ECU harness pinouts

Edited by Modrich on Tuesday 28th July 20:28

Edited by Modrich on Tuesday 28th July 20:29

[Modrich]

Have you checked the throttle body side? When running check for pre-ignition in the inlet/backfires etc which suggest poor AFR. After that whip the cam cover off and check the valve train and valve clearances...