LB7 tear down
#121
I can use air house on the sending unit with it plugged in and the key on and it'll read. I'll check the feed line when I get home. everyone I talk to says CP3 ECM FICM so I'm running outta idea to I'm going to try to get a buddy to come in from outta town and check the fuel pressure when cranking
#123
Join Date: Dec 2010
Location: Fool's Golden State
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make sure when you are checking fuel pressure you at some point unplug the pressure regulator to make sure it is not an ECM problem holding it shut.
what you want to watch for with the scan tool is "desired fuel pressure" and "actual fuel pressure". desired should be somewhere around 4-5k PSI or 27-35 Mpa. cranking RPM should be at least 100 RPM cold and 180 RPM hot
try it with a cap full of gasoline in the intake too to bust RPMs and see if pressure is higher
if you are getting pressure and no start then check the crankshaft position (CKP) sensor and the camshaft position (CMP) sensor. both of these can cause a no start condition even if everything else is ok
what you want to watch for with the scan tool is "desired fuel pressure" and "actual fuel pressure". desired should be somewhere around 4-5k PSI or 27-35 Mpa. cranking RPM should be at least 100 RPM cold and 180 RPM hot
try it with a cap full of gasoline in the intake too to bust RPMs and see if pressure is higher
if you are getting pressure and no start then check the crankshaft position (CKP) sensor and the camshaft position (CMP) sensor. both of these can cause a no start condition even if everything else is ok