Mechanics

K2500 7.4L

1994 GMC Suburban • 180,000 miles

Had a bad fuel pump swapped it out now (bad fuel pump for sure worked intermittently tested out of tank works sometimes and not others) now truck start but immediately if I disconnect vacuum hose from map sensor the truck will idle for a little bit maybe 2 -3 mins idle increases then truck dies I have used my multimeter to check all sensors and modules and all have proper voltage during testing also black smoke from exhaust it seams like for a little while with map vacuum disconnected it gets proper amount of fuel and the fuel cuts off also good fuel filter thank you for your help Scott
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Knzimad
April 14, 2013.



What is the exact fuel pressure?

Roy

ASEMaster6371
Apr 15, 2013.