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C7, can't get to crank after filter change.

tnc110

Well-Known Member
Joined
Oct 2, 2011
Messages
224
Location
western nc
driver complained out loss of power. Last time this happened it was a small inline filter being clogged (not sure if it is original.... looks like a lawn and garden type..) driver replaced filter. Said he ran truck for 1 minute, then it died. Tried cranking back probably 10 times. Fuel filter is full. Cracked fuel filter and cranked... No fuel pumping (not sure if it should with filter cracked? ). Opened fitting on tank for supply line and fuel was flowing (fitting is low on tank)

Is there a screen ast the fuel pump?
Suggestions?
 

Truck Shop

Senior Member
Joined
Dec 7, 2015
Messages
16,556
Location
WWW.
You say engine won't crank {you mean turn over or it turns over won't start}. Air in fuel system- needs to be primed. Does it have a primer pump? Or is there a
block off plate in place of the primer pump?

Truck Shop
 

thepumpguysc

Senior Member
Joined
Mar 18, 2010
Messages
7,445
Location
Sunny South Carolina
Occupation
Master Inj.Pump rebuilder
I KNOW this might sound stupid BUT> those "can filters" have an arrow for fuel flow..
Wont flow enough for starting or running but will slowly fill back up after emptying..
The ONLY WAY I found that out was w/ a glass one..
I was sent out to find a similar condition as yours.. I "looked" at the engine, saw a glass filter & it was full..
I got the driver to crank the engine & the filter emptied.. WTH?? After he stopped cranking, the filter slowly filled back up.. I thought it was a fuel cap vent problem.. nope..
Same thing happened when I took the cap off..
I looked closely at the filter & the "arrow" was pointing back towards the tank & NOT towards the inj. pump..
Took it off, turned it around & viola'.. a running engine..
 

Hobbytime

Senior Member
Joined
Sep 21, 2016
Messages
709
Location
usa
your problem could have been before the filter change with low power..you just assumed a clogged filter, but the issue could be a lot deeper..
 

crane operator

Senior Member
Joined
Mar 27, 2009
Messages
8,275
Location
sw missouri
Arent the c7 the high pressure heui pumps? Isn't that the way they act when they start to go, not to imply very bad problems, but that is a known issue with those engines......

If I remember correctly, the heui also can't handle any contaminated fuel, and they really don't like extended oil change intervals either.
 
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