MY 1990 C1500 5

  • Tiny
  • matttyw20
  • 1990 Chevrolet Truck
  • 130,000 miles

My 1990 c1500 5.7 TBI wont start unless I squirt gas in the bowls then it starts right up once started it runs fine and it never dies I can hear the fuel pump come on and onces its runing I can see a fuel comes out the injectors but when cracking there's no fuel from injectors but I took of the gas line when cracking and gas came the fuel pressure regulator is new I'm leaning towards the injectors or maybe a relay but i'm really not sure if you guys could please help me with what you guys think is wrong with it I would greatly appreciate it thanks Matt

Thursday, December 20th, 2012 AT 6:59 PM

6 Answers

  • Tiny
  • JDL
  • Expert
  • 16,236 posts

Check fuel pressure. Check voltage and ground at the injectors, engine cranking. Any applicable mil codes?

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Thursday, December 20th, 2012 AT 7:04 PM
  • Tiny
  • JDL
  • Expert
  • 16,236 posts

Just to add, engine cranking, the systems get battery voltage. Engine running, the systems get alternator voltage. The alternator voltage is higher, maybe three to four volts higher.

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Thursday, December 20th, 2012 AT 7:08 PM
  • Tiny
  • matttyw20
  • Member

Nope no codes when I squirt gas in the bowls it fires right up I noid tested the wires today and it flashed on both sides but no fuels comen out either injector when cracking but when I took the gas line off and cracked gas came out the fuel line and I know fuel regulators fine but once I start it by puttin gas in the bowls I look and the injectors are doppin fuel is it possible for the injectors to still be bad?

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Thursday, December 20th, 2012 AT 7:30 PM
  • Tiny
  • matttyw20
  • Member

And I ohm tested the injectors and I got 1.3 dont know if that good or not

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Thursday, December 20th, 2012 AT 7:31 PM
  • Tiny
  • matttyw20
  • Member

On both

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Thursday, December 20th, 2012 AT 7:32 PM
  • Tiny
  • JDL
  • Expert
  • 16,236 posts

I'd still want to check fuel pressure, key on engine off.

I wouldn't think both injectors would go faulty at the same time? Unplug one injector, then crank, see if other one would spray. Then the other one.

The only difference, I can see, between cranking and running, is voltage and rpms.

I don't know where to go from here?

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Thursday, December 20th, 2012 AT 9:54 PM

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