Join Date: Jul 2012
Location: Sacramento area
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Intermittent miss at idle
Looking for some ideas. I have what feels like a miss at idle that happens very intermittently, maybe once every 10 miles or so. I have only really noticed at idle, and when it happens RPMs drop about 100.
This started after I did some serious service to try to get rid of a long crank and stiction condition. I replaced the standpipes and dummy plugs, o-rings on each injector, and polished the spool valves as well.
Everything seemed to go back together perfectly. I did overlook something (which I realized afterwards). I forgot to clean out the bores for the injector hold down bolts.
My problem has been around ever since that work, so I'm sure I caused something. My occasional long cranks are still there, but she always turns over. Stiction is completely gone.
Some more info:
Sometimes I lose the signal from my MAF sensor, I think I need a new harness. It's hard to know when this crops up, but it does throw a code which gets me reading values on my monitoring system (Dashboss). I then monkey with the harness and it usually goes away.
I'm running a mild performance tune that is supposed to ignore the EGR valve. I had it off for several hundred miles with no change.
About 3000 miles before this work, I changed my oil cooler, EGR cooler (bulletproof version) and IPR (because I trashed it with debris from the work)
I'm running the blue spring and get high 50s low 60s fuel pressure all the time
I've run 5/40 full synthetic for the last 7000 miles. About 500 miles ago I switched from Schaeffer to Rotella T-6
Racor fuel and oil filters 7000 miles ago, and oil filter with oil change 500 miles ago
About a year ago I rebuilt my FICM and voltage never drops below 50.
I have a CCV reroute that completes the loop back to the intake before the turbo.
I think that's everything. I have pretty good monitoring through my Dashboss setup, so if a value might be helpful I can probably get it.
Any ideas are much appreciated.
2005 6.0 Lariat Crew Cab 4x4 Short Bed
SCT X3 Tuner, Looney Tune from Quick Tricks
Bulletproof EGR Cooler (I live in CA, smog mecca)
FICM with Atlas40 from FICMrepair.com
Updated Standpipes, Dummy Plugs and STC
4" Turbo Back Magnaflow Exhaust
DC Power 185 amp alternator and wiring upgrade
CAT EC-1 Coolant
Dashboss Monitoring including pyro and fuel pressure