john.z Posted July 4, 2021 Share Posted July 4, 2021 The drivers side runs leaner than the passenger side. Closed loop mostly corrects it, but closed loop disabled or full load i can see a difference as big as .15-.2 Lambda. I have ruled out my wide band sensors (switched sides, recalibrated etc), new 02 sensors didnt help (actually made it worse at idle) and the effect is the same on different injectors. is there a way to correct this? Quote Link to comment Share on other sites More sharing options...
Puffwagon Posted July 4, 2021 Share Posted July 4, 2021 You might have a slight exhaust or exhaust manifold leak which can suck air into the exhaust pipe and skew readings. 1 Quote Link to comment Share on other sites More sharing options...
Roland@pcmtec Posted July 4, 2021 Share Posted July 4, 2021 You could also have a clogged fuel rail. Had one instance of this where a car had sat for a year and the rail had rusted. 1 Quote Link to comment Share on other sites More sharing options...
john.z Posted July 4, 2021 Author Share Posted July 4, 2021 Checked fuel rails when I changed out the injectors and reg, car is a daily so always fresh fuel flowing. As for leaks, I’ve checked multiple times and come up with nothing, intake gaskets look fine, exhaust has no leaks. Got me stumped Quote Link to comment Share on other sites More sharing options...
Roland@pcmtec Posted July 4, 2021 Share Posted July 4, 2021 Cam timing skipped a tooth? Does it idle a bit rough? Compression tested it? Down on power? Do a power balance test with Ford IDS Quote Link to comment Share on other sites More sharing options...
john.z Posted July 4, 2021 Author Share Posted July 4, 2021 Honestly I never noticed it until I fitted the wide band. The car ran perfect. Even with cams it idles great, never stalls (manual) never hesitates and it’s power and torque is greater than others I’ve seen. Fuel economy is great. I fitted new o2 sensors the other day and it turned to crap, drivers side was running 17-19 afr at idle and it would stumble. Put the factory ones back in and it went back to how it was Quote Link to comment Share on other sites More sharing options...
Roland@pcmtec Posted July 5, 2021 Share Posted July 5, 2021 Have you tried swapping the widebands? If they still read the same try swapping the analog inputs/guages/however you are viewing the data. Quote Link to comment Share on other sites More sharing options...
john.z Posted July 5, 2021 Author Share Posted July 5, 2021 Yeah mate, swapped them around and re calibrated, no change Quote Link to comment Share on other sites More sharing options...
lukapuka Posted July 6, 2021 Share Posted July 6, 2021 I had this problem after fitting catch cans to the rocker covers. The rubber seal on rocker cover had split on the pcv side and was sucking air in. Quote Link to comment Share on other sites More sharing options...
john.z Posted July 6, 2021 Author Share Posted July 6, 2021 1 hour ago, lukapuka said: I had this problem after fitting catch cans to the rocker covers. The rubber seal on rocker cover had split on the pcv side and was sucking air in. My catch can vents into the boot before the throttle body, so not the case for me Quote Link to comment Share on other sites More sharing options...
john.z Posted July 19, 2021 Author Share Posted July 19, 2021 new intake gaskets fitted, exhaust resealed, checked for other leaks, fuel pressure is solid, compression is perfect, new spark plugs and more. still the same. this is my logging for fuel injectors. wtf is happening? Quote Link to comment Share on other sites More sharing options...
john.z Posted July 15, 2022 Author Share Posted July 15, 2022 For reference I found the problem, a common problem for the 5.4’s. Due to the drivers side secondary tensioner tensioning the wrong side of the chain, timing can vary a few degrees, causing a different AFR for that side. Flipped tensioner and decreeing the cams solves the problem. 3 Quote Link to comment Share on other sites More sharing options...
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