Spider injectors

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Dan1raysouth

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looking for steps on how to determine if the regulator or the fuel pump is bad?
I’m getting fuel to the fuel rail and every time 59psi it fires up but stalls after about 3 secs everytime. I replaced fuel pump and filter. I’m feeling like it’s the regulator because prior before this I was getting a lot of sputtering bogging and stalling under acceleration. Idk if it’s just a faulty fuel pump or injectors
 

mattillac

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Looks like easy to follow directions here.


They include links to related info.

: How To Test The ‘Spider’ Fuel Injector Assembly (4.3L, 5.0L, 5.7L).

: Difference Between A Bad Fuel Pump And An Anti-Theft System (PassLock) Failure.
 

east302

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looking for steps on how to determine if the regulator or the fuel pump is bad?
I’m getting fuel to the fuel rail and every time 59psi it fires up but stalls after about 3 secs everytime. I replaced fuel pump and filter. I’m feeling like it’s the regulator because prior before this I was getting a lot of sputtering bogging and stalling under acceleration. Idk if it’s just a faulty fuel pump or injectors
You’d need to do a pressure test with key on, engine off. It builds to 59-psi (60-66 is spec so you’re on the low end assuming an accurate gauge) but what happens when you turn the key off? Does it hold or drop quickly?

If it drops down fast, then there is a leak.

You’d need to put a valve in the supply line (in place of the filter) and one on the return. There should be a union in the return line near the filter for this purpose.

Pressurize the system, close the supply valve and quickly key off. If pressure now holds, then the leak is upstream of the valve at the pump.

If it drops, then it’s either going back through the return (regulator) or an injector, assuming that you don’t have a fitting leaking.

Repressurize, close the return valve and quickly key off. If it drops, then it’s an injector. If it holds, then it’s regulator since you have blocked the relief back into the tank.

As someone else mentioned, the Passlock system seems a reasonable culprit given the quick shutdown. If your battery has run down and you repeatedly tried to start it, that’ll sometimes trip it.
 
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