Cleaned fuel injectors and CO
Discussion
Hi,
I own a mk2 golf gti 8valve Digifant Bosch injectors/ECU/AFM. It was running rough and black soot from exhaust rich smelling.
It has been guzzling fuel, with the black exhaust and rich smell, you tend to think it is via the engine. I checked my FPR (fuel pressure regular by sucking on the vacuum line with a syringe and no fuel came through.
I pulled fuel injectors, cleaned them myself under pressure and pulsed them electrically to simulate injection.
Initially, three out of the four dribbled before a decent spray pattern appeared around 30 seconds later. One sprayed well from the start.
Now, my MOT last winter passed and they trimmed CO screw to meet CO limits.
As my injectors are now in better health would a proper garage mechanic need to adjust CO screw to ensure CO is now back in limits?
I'm still getting a rich fuel smell at exhaust and black soot.
My own thoughts are yes, i need to adjust the CO screw, I can do this and make engine rough, then 1/4 turn the screw back I think is the trick. I own a Gunson CO meter but I didn't seem to achieve same figures as MOT center machine so I may have been using it wrong, but I could use it to form a trend and opinion.
I'm fairly technical but have made some mistakes on the car so I want to get some advice before i dive straight in... again!
Any advice greatly appreciated.
I own a mk2 golf gti 8valve Digifant Bosch injectors/ECU/AFM. It was running rough and black soot from exhaust rich smelling.
It has been guzzling fuel, with the black exhaust and rich smell, you tend to think it is via the engine. I checked my FPR (fuel pressure regular by sucking on the vacuum line with a syringe and no fuel came through.
I pulled fuel injectors, cleaned them myself under pressure and pulsed them electrically to simulate injection.
Initially, three out of the four dribbled before a decent spray pattern appeared around 30 seconds later. One sprayed well from the start.
Now, my MOT last winter passed and they trimmed CO screw to meet CO limits.
As my injectors are now in better health would a proper garage mechanic need to adjust CO screw to ensure CO is now back in limits?
I'm still getting a rich fuel smell at exhaust and black soot.
My own thoughts are yes, i need to adjust the CO screw, I can do this and make engine rough, then 1/4 turn the screw back I think is the trick. I own a Gunson CO meter but I didn't seem to achieve same figures as MOT center machine so I may have been using it wrong, but I could use it to form a trend and opinion.
I'm fairly technical but have made some mistakes on the car so I want to get some advice before i dive straight in... again!
Any advice greatly appreciated.
I think Gunsons measures CO in a strange way, so pretty crap really ?
A wideband kit would be a little more use, although obviously it only covers mixture/Lambda assuming there are no leaks etc. It gives zero info on hydrocarbons, as does the Gunsons.
But in terms of getting mixtures close to lambda 1 which will in turn get the CO at a safe MOT level ( assuming otherwise healthy ), and just general tuning and ensuring mixtures/AFR's are where they should be, a wideband kit is fairly essential and good value.
A wideband kit would be a little more use, although obviously it only covers mixture/Lambda assuming there are no leaks etc. It gives zero info on hydrocarbons, as does the Gunsons.
But in terms of getting mixtures close to lambda 1 which will in turn get the CO at a safe MOT level ( assuming otherwise healthy ), and just general tuning and ensuring mixtures/AFR's are where they should be, a wideband kit is fairly essential and good value.
Edited by stevieturbo on Tuesday 21st July 21:03
Had similar issues with my MK5 gti, a cheap smoke machine from Amazon gave all the answers and where needing sorting.
Old plastic and rubber pipework, cracked and leaking joints, replaced the lot, no more running issues or EML appearing, pissed the mot.
Are you looking in the wrong place? Air and vacuum leaks have a profound effect on fuel management and code readers will only tell you the part that is not working correctly, not that leaks are causing it.
Old plastic and rubber pipework, cracked and leaking joints, replaced the lot, no more running issues or EML appearing, pissed the mot.
Are you looking in the wrong place? Air and vacuum leaks have a profound effect on fuel management and code readers will only tell you the part that is not working correctly, not that leaks are causing it.
Gassing Station | Engines & Drivetrain | Top of Page | What's New | My Stuff