1994 GMC K2500 SUBURBAN 7.4L

  • Tiny
  • knzimad
  • 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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have the same problem?
Sunday, April 14th, 2013 AT 9:01 PM

1 Reply

  • Tiny
  • ASEMaster6371
  • Expert
  • 25,556 posts

What is the exact fuel pressure?


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Monday, April 15th, 2013 AT 1:43 AM

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