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What does p1000 and p1233 mean?

2004 GMC envoy 4.2L i replace a new fuel pump assembly and the pump want run when i turn the key on and i don't hear the relay click the fuses are good the relay have numbers on it and they are #1, #2, #3, #4, #5, which one do i connected a jumper wire to to make the fuel pump run? is number 29, the fuel pump relay in the fuese box? do the inertia fuel shutoff switch red button suppose to be up or down? hope you can help me.

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  • GMC Master
  • 6,815 Answers

I take help from online websites that have this service like helping in repair some like reliable-store have instant help.. others are a bit slow which I don't prefer... rest is up to u.. U can also get free manuals

Posted on Mar 14, 2019


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Posted on Jan 02, 2017

  • 3854 Answers

SOURCE: fuel pump problems 2003 s10 chev 4.3 v6

Your ECU is what acctivates your fuel pump realy. Put the key on the run possition and pull the ecu fuse for a few seconds and reinstall it ans it should accivate your realy for 5 seconds, Good luck.

Posted on Apr 06, 2009

  • 1 Answer

SOURCE: 97 gmc pickup, 5.7 eng, fuel pump not operating,

What you need to do is check you fuel pressure. Go to a local auto parts store and buy a fuel injection pressure tester. The pressure fitting is on the top of the motor its a 3/8 ish sized metal line and has a screw on fitting like a tire valve does. This line comes up from the back of the motor to the right of the distributor and goes down into the intake. Make sure to have a rag handy to catch the fuel seepage. After you connect the pressure tester turn the key on and off three times and read the gage you should have atleast 58 pounds of pressure. If you have 56 pounds it won't run because the fuel injectors are a poppit valve style and need atleast 58 pounds of pressure to operate.

Posted on Sep 12, 2009

  • 49 Answers

SOURCE: new pump, no fuel pressure at fuel rail??

fuel pump relay

Posted on Oct 04, 2009

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SOURCE: 91 ford ranger...fuel pump will not run pump is good

It won't hurt to jump sire to drive, It is designed to pump all time when the engine is running. The only problem is the pump should not be on if engine is not running since it is designed that way to prevent a fire while pump continues on once engine is stops in a car accident. There is a control device to immobilize the fuel pump, if there is no speed sensor signal from the crankshaft. This needs to be located and fixed.

Posted on Oct 14, 2009

  • 15 Answers

SOURCE: I replaced fuel pump and

not knowing what kind of vehicle it is it is hard to tell. some gm cars and trucks have oil sending units that will not allow the vehicle to start unless it has oil pressure. they start going out and sometimes they start and sometimes they won"t.

Posted on Dec 08, 2010

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My 94 gmc g2500 vandura put new fuel pump in but it wont work when cranking check fuse replaced pump relay nd oil senor I have hot wired the pump nd it works its just not working with key

Have you checked for power to the pump from the fuel pump relay.After the key has been off for 10 seconds,turn it on and there should be a short 2 or 3 second pulse of power from the relay and you should also hear a click there.If there is no power pulse,is there power to the relay?Remember the relay only primes the fuel system and the oil pressure switch keeps power to the pump when it sees oil pressure.Is there power at all times to the oil pressure switch?On these vans the wire from front to the pump can go bad,quite a few have had a new wire run for the pump over the years.A great van.

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04 GMC Envoy with a 4.2 I have no power at the fuel pump the relay is working could the power control module still be bad or maybe the ignition switch

I don't know what testing you have done? Battery has a full charge? When you first turn on the key, no crank, can you hear the fuel pump run a for a couple seconds? Engine cranking you have spark at the plugs and fuel injector pulse? If you missing everything have to look for rpm signal, comes from crank sensor. If you narrowed it down to only fuel, you can see the fuse for load side of relay, in under hood fuse box. The control side of relay, right side in diagram needs voltage and ground. The black wire is chassis ground. The dark green wire with white tracer is voltage, comes from computer.
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The engine will crank but will not start why?

Do you have any codes or an engine light on, in your dash board ? Have you checked for spark at your plugs ? There are many things that could cause a vehicle to not start. Bad camshaft/crankshaft sensors. Poor ground wiring. Defective spark plugs or wires/coils.

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This may be related to the antitheft system. The system is known for turning off the starter and/or injectors when it fails. Normally when the injectors are turned off, the car will run for a second or two, and then stall. When it's the security locked out starter, you won't even hear a click when you turn the key. Is there a light on the dash that says SECURITY or a picture of a car with a lock through it? This is a common problem worth looking into. Do It Yourself GM Security bypass

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when you turn key to on position, not start position, you say you cannot hear pump hum for a few seconds, correct ? first check fuses, then find fuel pump relay, it may have a fuse in it also. I would replace relay first. after the fuses of course. if you still don't hear pump run, then your pump is most likely the problem. its in your tank. one more thing, make sure all grounds are good in this circuit. it could be that simple. good luck

Feb 21, 2013 | 1997 GMC Sierra

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Check your fusible links (wires that act like a fuse). The fusible links are located on the battery post on the starter, and some are located on the positive battery cable.

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fuse in the fuse box. also the power to prime the pump starts at the oil pressure switch. check that out too. then the relay for the pump in that order

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95 gmc 1500 4x4 will start sometimes but only runs for a few seconds. when it wont start there is no fuel in carb injectors are dry. any ideas? tried new fuel pump same thing.

do you hear the fuel pump run a few seconds when you turn the key on? did you check fuel pressure? replaced fuel pump relay? the oil pressure switch may have something to do with this.

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