Last week I had problems starting the truck. The engine would turn over, ignition, idle between 1000 and 1200 RPMs for about 5 seconds, and die.

Hooked the Disco up to a computer - said to change the crankshaft positioning sensor. A little painful, but changed it out this morning. Tight space!

Put the key in, started the engine. Ran a whole 7 seconds before dying. Tried again. No ignition. Waited half an hour, found the inertia switch (I think), tried again. It ran for 5 seconds before dying. Tried immediately again and no ignition.

Hooked the scanner back up. No codes.

I'm beginning to think it's the fuel pump but really need an expert's advice before blowing $700. Would love to test it first but have no idea - and for all I know it could actually be something else.

Any help is greatly appreciated!

 

You can rent a fuel pressure gauge at Oreilly to test the fuel pump. Sounds like you got a bad CPS out of the box, it happens.

 

As I'm in the sticks, renting a tool from O'Reilly or wherever is not really an option.

But it does seem to make sense that if the fuel pump is out, the engine will run until it sucks whatever gas it can out of the line before finally dying. And trying to restart immediately only results in cranking the engine with no ignition as there's no gas left in the line.

But after waiting an hour or so, after fuel has had enough time to seep through a dead fuel pump, the engine will run for 5-10 seconds until it sucks the line dry. An immediate attempt to restart ends up with no ignition. But if you wait an hour...

Odds of getting a bad part out of the box are pretty slim. I know it does happen, but so do winning lottery numbers. Thank you for your advice!

 

A bad CPS wouldn't allow the engine to run at all. It would have zero spark.

Have a tester delivered from amazon. They are inexpensive.

Fuel pumps are also not $700. You can replace the pump itself or just get a used one off ebay for like $100.

 

Fuel pump is cheap $75 cdn what’s that like $20 usd lol

 

All the cheap fuel pumps I could find for my 2001 D2 were missing a fitting for a hose on the top of the pump by the wire harness plug in. Check what yours looks like before you order so you can make sure they look the same. I cut a access flap in my carpet. Takes just a few minutes to take a quick look at the top of the pump before ordering.

Believe it was advanced evap loss fitting that was absent.
Could be way off in the terminology.

I was having issues starting and running at one point/was throwing lean codes. Did Cps, still had issues. Replaced the fuel pump and its ran great ever since.
Got one used on Ebay for about 50 bucks shipped.

 

Before you spend money a fuel pump since you have found the schrader valve it is easy enough to jumper the fuel pump relay and check for fuel at the schrader valve. Does not have to be a fuel pressure gauge, any pressure gauge will work, even a pencil tire gauge - if I recall the factory pressure is around 55.

 

First off...the engine doesn't suck fuel. It's fuel injected and has to have the correct pressure to ensure even-mixture of fuel through injector. So, if it is running for a few seconds...it has pressure for that amount of time (and may afterwards...but you're not sure). Fuel will not seep through the line to the engine, it has to be pushe through by pump.

Second...what do you mean by...no ignition? Do you mean it cranks but doesn't start or cranks and there is no spark (at plugs)?

You could still have an issue with the crank sensor, maybe bad connection at plug (terminals sometimes get pushed out of socket), wiring harness issue, etc.

Me...l'd be immediately checking for spark after it quits, all four on one bank. Also, need to verify fuel pressure or at least find out if the pump is running (while cranking). You need to start verifying conditions and eliminating possibilities one by one.

Good luck.