Long story short, I got a 97 K2500 with a brand new 5.7L in it. Motor has around 1500 miles. Truck won’t start. Has good spark, has fuel going up to the injectors (with great fuel pressure) but the injectors are not pulsing allowing the fuel to go through. I’ve replaced injector spider, cam sensor and crank sensor, fuel pump is only a month old and was working fine (still is, again great pressure). I’ve also replaced ECM and had it flashed at a dealer. Still nothing. I’m at a complete loss and not sure what else to check/replace. Any help would be much appreciated!

Thanks,

Nathan Gilronan

How many PSI of fuel pressure when you're trying to start it?

What changed about it between the 1,500 miles and now? . . . as in did you just buy it from someone with 1,500 miles on the engine? . . . or you installed the engine yourself and drove it 1,500 miles and now it quit?

Did it quit while running or did it just not start the next time?

How many miles are on the rest of the car?

I like to see around 60psi on those. I've seen to many that are at 56psi or so and will not get fuel.

It’* a brand new crate engine. My father and I swapped it in because the old one bent a valve. The truck ran fine at first. Then recently when you’d hit the gas in Park itd fall on its face. And putting it into gear would almost stall it. Fuel pressure is at 60psi with key on and during crank. Body has 220k, trans has 220k, rear end is 180k ish. If you spray starting fluid it’ll fire up until the starting fluid is gone (so just a few seconds). I have good spark obviously (which was also verified by a Chevy dealer when they flashed my new Ecm). Only sensors I haven’t replaced are the ignition control module, IAC sensor, or Throttle position sensor.

Crack the throttle open a tad when you crank it again.

Tried that, no dice.

Gotcha.

I hate this injection system...

dumb idea, did you check the injector fuse? If your not sure on location, you can always verify 12v when ignition is switched on by probing any of the 4 injector wires. The PCM controls the injectors by providing the ground control.

It’* getting the 12v signal it should, and the pulse wires are grounding like they should during crank. Thought it was the ECM since it was 22 years old and figured it crapped out. 450$ later and wasn’t the issue.

Just a quick thought. Did you check your tps value? It maybe reading too high and in clear flood mode, that shuts down the injectors.

I have not. How would I go about doing that? I don’t have a fancy snap on scanner or anything. Just a typical 100$ scanner with a few live data features. I forgot to add as well in the original post, injectors were able to be fired manually with a snap on scanner one of my dads friend has.