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1994 C1500 V6 - fuel injectors won't spray


Wesmorton
07-16-2016, 11:19 PM
Circumstances landed this truck in my lap after it sat for 2.5 years. I would like to get it running. Oil level was ok, and coolant was ok (will change both soon). Got a new battery immediately.

Gas tank was nearly empty so I added 5 gallons fresh gas (with StaBil).

Have not tested fuel pressure, but have confirmed fuel is making it to the throttle body; I disconnected the fuel line leading to throttle body and turned key to prime... gas gushed out (these are tricky to reconnect). However, when actually cranking engine fuel injectors not spraying, only a very weak drip.

Added gas directly to throttle body and engine starts, roughly but stays running if you pump gas pedal and keep adding gas. Otherwise, it dies.

Connected noid light to fuel injector connector...noid lights up when cranking engine (both injectors).

Opened up the extremely dirty fuel pressure regulator. It was completely rusted out with a broken spring. Bought a new one. And bought new fuel injectors.

Tried starting engine, same result - no spray from injectors. So I took the ignition control module to Auto Zone and it failed their diag machine. So I bought a new one.

Still same result, no spray from injectors when cranking engine, only a very weak drip (almost nothing).

Quick summary of things I bought/did so far -

new battery
5 gallons fresh gas
replaced fuel filter
replaced fuel injectors
replaced fuel pressure regulator
replaced ignition control module

Please set me straight, I appreciate the help and knowledge -

thanks

j cAT
07-17-2016, 07:52 AM
this is what you did wrong gas tank almost empty you added new gas . no this is bad.

drop tank flush out fuel tank remove pump inspect for damage, replace fuel filter cut open inspect for damaged broken filter media. if broken clean out the fuel line to the engine. good luck,.

Schurkey
07-17-2016, 08:49 AM
this is what you did wrong gas tank almost empty you added new gas . no this is bad.

drop tank flush out fuel tank remove pump inspect for damage, replace fuel filter cut open inspect for damaged broken filter media. if broken clean out the fuel line to the engine. good luck,.

Good advice. Covers all the bases.

I would short-cut. Check/replace the fuel filter, and test the fuel pressure at the TBI unit. I suspect low fuel pressure--either a failing pump, corroded wiring to the pump, and/or a plugged filter.

MikeCStig
07-17-2016, 07:27 PM
Gas tank was nearly empty so I added 5 gallons fresh gas (with StaBil).

This is where you missed the mark for 2 reasons. First, the time to add stabil is before the fuel sits around for an extended period of time. Adding it to fuel that's about to be used (old or new) is pointless.
Second, you say the "nearly" empty. You should have drained it before adding fresh fuel. Just to be on the safe side you may want to drain the tank now and put some fresh premium fuel in.
When you do get to fuel pressure testing, chances are it will be low. If this is the case, the fuel pump is the most likely culprit.

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