Help with no-start on 2008 Express van

NYSpeed Automotive
1

Trying to help my dad out with his 2008 Express 2500, 2WD, 4.8 LS powaaaa.

It died on him in traffic, we towed it to my place. It would intermittently start and die, felt like a fueling issue. Fuel pump did not prime for 2 sec on Key On, so I checked the fuel pump fuse and relay, both of which tested ok. I replaced the fuel pump, and it still won’t start. I am not getting the 2s prime with Key on and about 3/8 tank of gas. For fun I pulled the high pressure fuel line to the rail where it connects to the fuel pump outlet and it’s bone dry - obviously not sending fuel to the rail.

I pinned out the Gray and Black wires on the connector to the fuel pump. 5.5V at the gray (power wire) with key on, drops to ~3V with key off. I’m at a loss here. Is there a ground, switch, or relay somewhere that I missed? Would a bad ignition relay cause the PCM to not send power to the fuel pump relay?

Any help is appreciated, thanks.

2

Pull the line at the pump. Is it wet there? Maybe a blockage somewhere. I know you said it won’t even prime but there has to be fuel somewhere or the pump is dead.

3

the line that goes from the fuel pump to the fuel rail is dry, no fuel there.

The pump is new, I’m wondering if there’s a bad ground somewhere that’s causing it not to come on. Delphi pump.

4

How much for the motor and trans???

5

Can you direct wire the pump to rule out that it’s not bad. Check pins in the connectors see if one is slipping out. Iv had that happen on the BMW.

6

Lmao I’d keep it and do a big single sloppy style in an old shitty Volvo or American land yacht

7

this is a long shot, but does that truck have an oil pressure cut off relay?

8

I’ve been reading here and there about that problem - apparently if it sees no oil pressure it will kill the fuel pump. No clue where that cut off relay is, though.

Also saw some stuff about grounding straps going bad. The one on the passenger front side doesn’t look great, but it’s technically still in one piece. It’s the color of the statue of liberty though, so I’ll experiment with improvising some new grounds using big jumper cables.
I don’t know if this has anything to do it with it, but is probably worth mentioning - about 1 hr before the van died I installed a trailer hitch on the van’s frame (did not mess with any wiring). I wonder if the jarring force from the impact gun tightening the carriage bolts was enough to break any ground straps/wires that were on the edge of failing. Doubtful, but you never know

9

Found a bad ground between the chassis rail and block last night. Rigged a jumper cable and she fired right up. New ground cable going in today, direct from chassis to battery. Not sure why they played this stepping stone game with ground routing, probably to save material cost.

10

A lot of those engine sensors reference the block for ground so make sure that is properly grounded as well.