Hello Everyone, Love the Show,
I'm a diy mechanic with a 1997 Ford F-150, 4.2 V6, rebuilt 8000km ago and when I bought it, it had several problems, which I have fixed. Thanks to Scanner Danner I found a hidden vac. leak that I am sure previous mechanics did not find due to the location and the rusted bolts that were never taken off!! It was behind the battery case next to the firewall, a line right out of the vac. tank. Anyway after replacing one o2, B2S1, because it was reading straight lean with no response, I now have a rich condition that I can't make sense of. Before with the vac leak, I had lean and rich codes now I am just getting rich codes and still goes into closed loop fault after a couple of minutes, then open loop fault. While it is in closed loop at first, all 4 O2.s are at .8, to .9 volts and the computer is taking away fuel -20 on both banks, also I should mention that the truck starts great, runs great, except for the black smoke due to rich condition! I did a compression test and that checked out, vacuum on the engine shows 17 or 18 hg steady, checked for plugged exhaust and that seems good, No backpressure, I don't have a long term FT numbers for some reason, not sure if its because it never stays in closed loop long enough for it to get there? or some other reason? I have excellent fuel pressure and the regulator works as it should with no leaks, did an injector balance test and they all drop 6psi, also took them all out and cleaned the screens & checked to see if maybe one was stuck or something, ran cleaner through them with no issues! Checked and replaced EGR, PCV, Purge solenoid. I was concerned about the MAF readings before, so I replaced the sensor and the one I bought from Rock Auto is a BSE unit and it is reading the exact same at idle which is between 7-9 grams/sec which I think is high. I'm pretty sure it should be around 4 or 5 for this motor? but the last time I took it out for a drive, it did not go higher than, I think, 120 or 130 g/s! and the old unit 160 or so. But these are the codes it threw, P135, P155, P141, P161, P1132, P1151 It has a K&N cold air intake. All the other numbers seem good, Intake Temp, Tp, load, cool. temp, My timing also I am not sure if its normal, but it fluctuates between 14 and 24 at idle? My manual says it should be 15 deg.BTDC at idle, but I am thinking that the refresh rate on my code reader might not be fast enough? Is my timing wrong, or could it cause the rich condition? Its set by the ECM and cant be adjusted so,,, anyway I really don't know where to go next ? I am waiting until I can afford a oscope and a bi-directional scanner to be able to do more tests but until then.... Another question I have is, on the 5v ref for the MAF i get 5.8 volts? Is this normal or could that be why my Maf readings are skewed?? Again this Canadian is a big fan of the show and have learned alot, I am in school now for my red seal in Plant Maintenance and will probably buy your book and join your classes when time allows! Any feedback would be greatly appreciated, Thanks
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