99 suburban no start - 6.5L TD

[dukeofurl]

Ok, this is REALLY WEIRD.

 

As some of you know, I bought my super rare 99 LT 3/4 ton 4x4 diesel suburban recently, and it was literallly - a miracle that we found one like this because thats a very difficult truck to buy. It went one week and "sold" and the next week it was not available and we bought it as a result.

 

Today was weird - someone wanted to test drive it and I just put in a new wiper fluid pump, despite GM not knowing how to make a pump that dosent fall apart after 7 years and plastic nitrile tubing that cracks and gets brittle as well.

 

The potential buyer tries to start the thing - it starts and then stalls out. Then it starts running again and then dies. It won't start back up. Glow plugs are kicking on and off and both batteries have a sufficient charge to keep up. He cant give it a little pedal since its a diesel and you don't flood it like a gas engine.

 

I managed to get it running on ONE battery once when I had the other battery removed to fix the fluid pump and I just ran it yesterday to make sure I hooked everything back up correctly.

 

So I'm scratching my head as my partner calls me up and says "What the f**k did you do?" and I tell him it was running yesterday. I'm GUESSING it's a no fuel condiition, so I popped the valve covers and the filter is getting fuel. I stuck the key in and started it and kept it running on the first try.

 

So, I've got a few thoughts.

 

A: Injector pump is going bad. Thats a $1000 fix. That would cause no-start.

B: Fuel pump in tank is going bad. Thats a $500 fix. That would cause no start.

C: Maybe a bad relay or computer sensor not kicking the fuel pump circuit or its detecting WOT and knowing to deliberately cut off fuel.

 

Anyone?