Plugs - 2 lean 2 fat

[Exigeman]

I have been chasing the problem of plugs 1 and 2 being maybe a little lean while plugs 3 and 4 being quite rich/fat

Injectors tested, COP tested, no air leaks ..

Any clues please !

M130 with IGN4 - Duratec I4

plugs1.jpg (113.64 KiB) Viewed 183 times

[David Ferguson]

If you swap injectors, does it follow the injectors?

Does the intake or exhaust favor one end of the engine (less bends, etc). If so, can you dial in the plugs with per-cylinder fuel trims?

What was the running conditions before you removed those plugs (just normal driving, long period of idling, ignition cut after a long WOT run at top RPM)? What is your fuel mixture aim in that running condition? Have you checked them under other conditions.

Any indication of misfiring, or injector diagnostics in the logs?

[Exigeman]

Thanks David
- I have not yet moved around the injectors, they are new Bosch (from Bosch) - will get them tested to be sure
- The exhaust is as close as possible like to like and same design is used on another unit with no issues
- Inlet for air box is at nos 4 end ..
- New plugs and some slow speed running with a few hard runs to max in 2/3 gears then some slow/speed idle back to base, no long time at WOT at all.
- Will check the logs, I did get an alarm after one run