Keeps shutting down as soon as warmed up. Replaced ignition module under dist cap. Nothing. Starts, runs from 3 to 4 miles then shuts clean off. Sometimes starts back after a few minutes but mostly when its cooled off. Just before shutting down, it makes low , almost growling sound like the first part of an owls 'whooo' that seems to come from the master cyl area abouve drivers feet. Fuel pump? CLogged filter? Loose wires? bad pump relay? I dont know what to do and am losing work! Its a 350 with injection. (tbi?)

 

you say it will run from 3 to 4 miles, have you let it idle? I mean if you start it and leave it idling, will it die when up to temperature?
Is the engine thermometer reading 180 degrees? pay attention to the temp and see if it is occurring at a specific mark.
Also does it sound weird when you start or run it?

 

I let it idle once for about 10 minutes and it died. Its never made it to 180 degrees. Sounds normal to start and to run. Someone told me my new ignition control module could be bad out of the box?

 

it's possible I've bought defective parts before
is it dying while on the gas or only when idle?
If it is only dying during idle, it is possibly idling to low (check your throttle cable and tighten if needed to increase idle at operating temp.
When was the last time you cleaned out your throttle body? cleaned the IAC (Idle Air Controller)?
fuel pumps can have problems if they are worn out and get hot.
when you replaced the ignition control module, did you go ahead and to the whole distributor (cap, rotor and all)?

 

Its done it at idle and going down the freeway. I know nothing about the injection system. Im an old carb guy. Used to changing valves in Holley double pumpers, lol

Again the STRANGE thing is the little low pitch 'whooo' type humm you hear for about 1.5 seconds just before it dies. Sounds like its coming from around the master cyl area or up under the drivers side dash. Wife heard it too. Im fit to be tied. Need this for work! Cant afford to send it to a dealer for diagnostics--they are well over $100 an hour.

When it dies, it simply feels like you cut off the fuel supply with a dead switch. No stumble, no hiccup. The starter will immediately work and spin the engine like a top but no fire. A couple times it did almost catch and then felt like it was catching some fumes in the line after running out, but its got 1/2 tank of almost new fuel.

 

most auto parts stores will let you use their scantool for free to check engine codes.
I'm starting to think your fuel pump is going bad and won't operate at temp. I would start the suburban, then listen to the fuel pump and see if it goes quiet before it dies.
It is inside of the fuel tank.
or it could be the fuel pump relay It's on the firewall inside the engine compartment (closer to the passenger side).
Probably has something to do with not getting fuel.
clean the throttle body and IAC anyways, never hurts.

 

I would use a fuel pressure gauge to see if you are getting good fuel,
If you are, then that eliminates it to either air or electrical.
If your air filter, throttle body and IAC are clean, I would assume it was electrical.