Ok so i just went to check the FPR and immediately found a problem, not what i expected though which was either fuel in the vacuum hose or a blockage in the return line, as soon as i put my hand on the FPR it moved. It was bolted down, just not tightened down and i could jiggle it a little bit, i took it off anyway just to check the o-ring which seems in great shape, put a dab of oil on it, bolted it down correctly and connected the hoses back up, no more jiggling. This can only be my fault from when i took the fuel rail off to get the injectors out and clean them before last years MOT
Question is though could the issue have been as simple as this, and how did fuel not find its way out from between the fuel rail and regulator, i guess the o-ring just about held it back but how else would this effect fuelling? Could it have worked itself loose over time to create this issue?
Back on the subject of the emissions values again, 2017 MOT results:
Fast idle
CO < 0.30%vol
0.38%vol FAIL
HC < 200ppm vol
64ppm vol PASS
Lambda: 0.970-1.030
1.026 PASS
2nd Fast idle
CO < 0.30%vol
0.20%vol PASS
HC < 200ppm vol
44ppm vol PASS
Lambda: 0.970-1.030
1.023 PASS
Natural idle:
CO: < 0.50%vol
0.49%vol PASS
2018 MOT results:
Fast idle
CO < 0.30%vol
0.86%vol FAIL
HC < 200ppm vol
138ppm vol PASS
Lambda: 0.970-1.030
1.023 PASS
2nd Fast idle
CO < 0.30%vol
0.80%vol FAIL
HC < 200ppm vol
95ppm vol PASS
Lambda: 0.970-1.030
1.013 PASS
Natural idle:
CO: < 0.50%vol
0.63%vol FAIL
What i don't know is what happened to these numbers when i went for the retest as at that point the plugs had been cleaned and re-gapped and a new air filter fitted along with fresh oil. All i know is there was a minuscule improvement in the CO reading and a bit less fuel smell.
Both the CO and HC have doubled but HC is still within limits, high HC as far as im aware indicates raw fuel and high CO indicates incomplete combustion so seems to point to a rich fuel mixture which then resulted in unburnt fuel?
Anyway i just took her for a test drive, i don't know if its in my head but she seems to pull easier from low rpm when before there was some hesitation until around 2500rpm, i dont see any more smoke/mist through vtec although it was quite sunny just now so its hard to tell, and overall she seems to pull smoother. I swear she idles a tad lower, say 50rpm and when i hold the pedal at high idle, say 2000rpm she holds more steady, there is a tiny bit of hunting but its barely even 100rpm. Also had a little sniff of the exhaust after the drive and i don't think i can smell anymore fuel...
Surely this tiny change cant be it, what do you guys think, try another test? If it works i will be amazed