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Electronicals / Forscan Expert
Joined: Fri Nov 24th, 2017
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Flat spot on the cam? Dirty mass airflow sensor?
I've HEARD a little tranny fluid in you oil can free up stuck stuff but I've never needed to try it.
Techron is great in the fuel system, I've used it and it really
works well. My truck had an ever so slight surge Idle I could only hear in the drive thru with walls on both sides of the truck. Put techron in it and the engine smoothed out. It was kinda weird cause it had always had great performance and acceleration but now it was really smooth at idle too.
The issue is intermittent and doesn't show up on a cranking compression test, so to me this would eliminate a flat spot on the cam.
Fuel trims look pretty darn good through out the entire power band (there are occasions where the STFT go up to 15-18 at a stop light and go back to normal), plus it seems to be only cylinder 2 that is misfiring as I did a cylinder contribution/drop test. I pulled injector connectors instead of spark plugs because of the dual spark system and cylinder 2 was the only one that didn't make a difference. Cylinder 1 is fired right after cylinder 2 so I think the cylinder 2 misfire is causing cylinder 1 to pop up every now and then. Or maybe it's both Cylinder 1 and 2 sticking a different times and sometimes it's both (why I stall out on occasion due to only 2 cylinders firing).
Some MMO in the crankcase months ago seemed to help but that could have been a placebo effect. .
I'm thinking at the end of the day the valve cover is definitely going to have to come off. I may try the penetrating fluid, tap valve stem top method. Need to also inspect springs and possibly remove and clean the hydraulic lash adjusters (they have been ticking for years). I've bought 5 gallons of PSC 1000 (naptha) for my parts washer so I think that would be a good solvent for those.
A couple of tests I may do before the valve cover pull is an injector flow test just to eliminate those (got an injector pulser off Amazon for $30) and also try to do a running compression test.
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2000 XLT 2.5L A/T 2WD
Mods:
Power Windows/Locks Mirrors using OEM harness and parts
Explorer Sportrac White Face Cluster
Explorer OHC and Auto-dim Mirror
Auto Door Locks
Full HID Projector Retrofit