Right my R's not been at its best lately. FWIW its running a chipped ECU, programmed for 1.2 bar boost which is achieved with a dawes device. It also sports an exhaust that's holier than the Pope! ( )
I'll give you a very quick run down of symptoms:
it was chucking out a heap of soot onto the back of the car.
very little power/torque before turbo kicks in.
turbo hits full boost maybe just after 3.5k rpm. The turbo was recently rebuilt with a 360° thrust bearing and updated compressor (?) wheel and is fitted with a Bogdan 3" elbow so should spool up earlier.
when at WOT the car rarely feels punchy and always feels like its being held back by something.
Things I've tried to sort it:
New engine/ECU temperature sensor.
Knock sensor replaced and temporarily located on side of head. (I know, I still have to put it back behind engine at some point!).
New ignition coil, amplifier.
New leads, dissy cap and rotor arm; all original Nissan stuff.
Re-earthed the fuel pump and relayed the power feed (showing healthy +13.5V at pump)
Reset ignition timing to bang on 20°. No messing with riding the clutch here, just turned on fans and headlights to get idle down to ~800/850rpm so very confident this is right.
Fuel pressure regulator replaced with adjustable one but set to 3 bar. I had installed a gauge on the original FPR but it was showing about 3.5bar at idle so I replaced it. It looked a bit furry inside too!?
I added a couple of additional earths to engine & chassis to rule out a dodgy contact somewhere.
Moving the (new) knock sensor to the side of the head definitely improved the sooty boot I had but the car still wasn't right. Everything I've swapped above also seems to have helped but not entirely cured the issue.
So now to the original question...about the plugs. I had a spare set lying around so thought I would change them out as the plugs had been in for about 10 months/5k miles (fuel filter was replaced then too btw).
To my unprofessional, untrained eye they look fine to me. Maybe a smidge on the lean side but nothing to say its running massively lean IMO. What do you guys think?
Also after seeing the plugs I upped the fuel pressure to 3.3bar as a trial today. The car still seems to come on boost a bit late but definitely pulled a lot cleaner up in the rev range.
You think maybe my MAF is out of whack causing slightly lean running? Looking at the plugs I wouldn't say that one or two were any different to the rest so I (personally) would rule out clogged injectors. Also (just remembered this) the car intermittently throws up a code 11 for the CAS. I don't know if this is related or not though...
cheers for now,