Indicators of a plugged fuel filter
Many times the fuel filter on the 6.5 can become plugged up to the point that performance starts to drop off and you really don't notice it right off.
Now many times the engine will start to sputter and miss (Very obvious)
Was out the other day with DaHoooley and cruised into Portland to get some stuff and on the way back the rig started giving issue.
After 20 miles of steady freeway driving and no issues, I pulled down an off ramp, (decell for maybe a 1/4 mile) and at the bottom, made a quick stop and then a left turn. Rig started stuttering and missing something terrible.
I continued to accellerate and the missing cleared up.
Hmmmmmm after another 10 miles I had another 1/4 mile decel and then a left turn, same missing and stuttering. Then tried a decell after a bit and a right turn, same thing.
Got home, yup, fuel filter full of crap. Some water in the clear bowl (have Racor 230R2 (2Mic)
Removed the screw on filter and in the process shook it a little, OMG the bowl filled up with all sorts of black crap.
Changed out the filter and all good as new again.
Never go on a wild chase for stumbling issues without first checking the filter.
The stock filters on the 6.5 are a 5 micron and will pass a lot more junk but this is what they are.
The little stock filter is way too small IMHO for the application.
These rigs process about 30 gallons of fuel an hour through the filter and back to the tank.
What happens during a long run and then a decel is that there is a partial vacuum in the fuel tank. A partially or nearly plugged filter offers a lot of backpressure for the lift pump to overcome and with the low demand of the transfer pump as the engine speed slows, the fuel transfer through the filter comes to a near standstill.
Upon accelerating again, the transfer pump cavitates (sucks a hole in the fuel flow and churns air) and the stumbling and missing occurs.
Once the transfer pump gets enough suction back on the outlet side of the filter again the flow will pick back up and the missing will clear out.
This situation will go until the filter is just too plugged up to pass fuel then its game over.:eek:
Sooooo there it is.
Hope this helps.
Missy
