1990 GMC Suburban fuel pump

Tiny
JIMBO TOOKALOOK
  • MEMBER
  • 1990 GMC SUBURBAN
Electrical problem
1990 GMC Suburban V8 Four Wheel Drive Automatic

Suburban stalled came back to life, drove eight blocks stopped then stalled and would not start. New fuel pump relay, clean filter, clear injectors.I disconnected power to fuel pump at clip, were the fuel pump hot wires connect to power. I tested with test light, getting power to pump. In conclusion fuel pump must be out?
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Saturday, May 1st, 2010 AT 12:38 AM

5 Replies

Tiny
INTERNETMECHANIC
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My wiring info for your model year isn't great. Did you test at the fuel pump connector, at rear of vehicle? With engine cranking, the tan wire with white tracer is voltage for the pump motor. Black is usually ground, my info info didn't show ground wire. If good voltage and ground at the pump and no pump action, I suspect the pump. Did you check for fuel pressure with a gage?
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Saturday, May 1st, 2010 AT 11:16 AM
Tiny
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* Yes I did check at Fuel pump connector. Wire Red got power strong light, Tan no power must be ground? Does that sound right to you? These wires are coming from power source to connector clip then to wires to fuel pump. I don't have a Pressure Gage, but when I checked the Fuel Filter there was some Pressure, so I don't think there any pressure now since the Fuel pump has 'NT came back on. Thanks for your time and help.
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Sunday, May 2nd, 2010 AT 3:17 PM
Tiny
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The tan wire with white tracer is voltage for the pump motor, the pink wire should be voltage for the sending unit, gas gage. Some of the national brand autostores used to loan out a fuel pressure gage, if you don't have one?
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Sunday, May 2nd, 2010 AT 4:23 PM
Tiny
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So then if the tan with white isn't getting power what would be the problem?
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Thursday, May 13th, 2010 AT 4:26 PM
Tiny
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Possible problem with the relay or relay circuits. Check the ecm B fuse and circuit for voltage.
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Thursday, May 13th, 2010 AT 9:49 PM

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