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No fuel

J

jethro128

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Arlington, Tx
Ok 86 suburban with 96 5.7 in it. Good fuel pump, fuel filter, but the injectors on the tbi arent pumping at all. Someone said pick-up coil. If there is spark does that mean it is ok? Tested control module and it's ok. Is there something else I am missing?
 
Are you sure you are getting pressure up to the injectors?

You can force the Fuel Pump to operate in test mode via terminal G of ALDL connector (apply +12Vdc from a fused source (10Amp). Connect Fuel pressure gauge to verify that 11 to 14 PSI for stock TBI is present. You should also hear the pump.

Also check the oil pressure switch by the dizzy to make sure it's hooked up. No oil pressure no fuel..

or

Get a test light without battery , Volt meter is going to be to slow to react to pulses). Connect ground lead to the ground and probe the blue or green wire terminal of the injector connector. Test light should be lit when engine is stopped, ignition in run position.
Have a helper crank engine while observing light. It should be blinking on-off and injector spraying while cranking. If light remains steady on then ECM is not receiving DRP pulses from dizzy.

Let us know
 
Is this Vortec or TBI on a Vortec block?

I am not an expert on the Vortec setup in regards to injectors, however on TBI you would want to disconnect the injector connector and use both wires of the test light, one in each connector cavity, as the fuse panel side is 12V constant, the ECM gorunds the other lead to pulse the injector. Can't see pulses watching the 12V side.
 
WHEN are you not getting fuel? Again I can only go by the OBD1 systems that I know, the fuel pump only primes for a few seconds without the engine running, and should only get power again if the engine is turning over/running.

It's either ignition (well, ignition signal to ECM) or fuel, no ignition will likely mean no fuel.
 
I'm going to say this one more time, I am not certain on Vortec setups if this is correct. :)

If you don't have spark, that is likely the reason your fuel pump is not running. Ignition module is a common cause of this, however the Vortec motors use a crank position sensor I believe, and this may have taken the place of the ignition module for spark indication.

Nothing shuts off spark on the engine except a failure of some sort (power, short, module, etc) while the fuel can be, so work on the ignition first.
 
OK I think it is Vortec with TBI. I am wrong about the spark though because if I prime the tbi with a little fuel it will start. If by ignition module you mean the one under the distributor cap I checked it and it is ok. I am not getting fuel at any point in time. The pump doesn't pump at all. I know it is good though as I hot wired it and it pumped fine. The injector's are not squirting any fuel into the throttle body at all.
 
dead fuse?

Earlier there was a relay and oil pressure switch to be redundant in this regard, I suspect GM kept doing this, but not positive.
 
Where is the fuse on that setup?

Mines in the engine bay, is yours on the fuse panel?
 
You have to remember mine is a frankenstein so for me it was under dash behind glovebox right next to computer.
 
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