'97 C1500 5.7 V8 Odd problem

[618 Syndicate]

Yeah, "fuel".

So why no fuel?

- ECU not firing the injectors (either intentionally or because of internal failure)?


- injectors not receiving fuel (OP says "pressure" is there)?

- injectors firing and delivering fuel, but delivering insufficient fuel for some reason?

If it was insufficient fuel my guess would be it would try and run, just sputter.

 

[PlayingWithTBI]

OK, the ECM/PCM has to see DRPs (Distributor Reference Pulses) from the ICM to fire the injectors, right? If there's nothing wrong with the wiring and PCM then, maybe the ICM is bad? YMMV

 

[clgodwin79]

I’m assuming we’re talking TBI? Or Vortec?

 

[DocBernard]

I believe this is the vortec

 

[clgodwin79]

It has to be fuel. When you introduce fuel it runs. Even if a MAF is bad, it can run, just run like crap. If fuel was already getting there it would run, but run like crap how it is. Adding straight into intake and it runs means fuel

 

[clgodwin79]

That’s true that it could also be the ignition control module though. I didn’t realize that the ECU/PCM needed to see it to fire the injectors.

 

[clgodwin79]

I believe this is the vortec

What year is it? 88-95 TBI. 96-98 Vortec

 

[PlayingWithTBI]

I didn’t realize that the ECU/PCM needed to see it to fire the injectors.

Yep, otherwise it would fire the injectors with KOEO

What year is it? 88-95 TBI. 96-98 Vortec

The title says it's a 97

 

[clgodwin79]

So for fuel to get to the injectors it has an electric pump, lines all the way, filter, fuel pressure regulator built onto the back of the spider injectors and then the actual injectors to get the fuel into the cylinders.

Other than the already mentioned ICM that apparently has to function for the ECU to actually fire the injectors.

I’ve never had a regulator go out, but if it did, fuel would be present all the way to right before the injectors.

 

[clgodwin79]

Yep, otherwise it would fire the injectors with KOEO


The title says it's a 97

Makes sense