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So I left my truck sitting for about a week while I was on vacation. I try to start it up for the first time and it'll crank all day but won't fire. My gauges aren't working, my odo is flashing my mileage, and my lift pump isn't getting any power. What do I need to look into besides checking all the grounds and fuses? Does this sound like a bad ECM/PCM? Thanks for any help.

 

The truck is a 1998.5 

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Yep that looks normal to me.  Your check engine light should come on for 3 to 8 seconds (depending on how cold ambient temp is) when you turn the key forward then go out.  If your CEL is not doing exactly that then something is not right with pcm/ecm.

 

The fact that you can't connect to read codes strongly suggests pcm/ecm problems. 

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4 hours ago, Bullet said:

Yep that looks normal to me.  Your check engine light should come on for 3 to 8 seconds (depending on how cold ambient temp is) when you turn the key forward then go out.  If your CEL is not doing exactly that then something is not right with pcm/ecm.

 

The fact that you can't connect to read codes strongly suggests pcm/ecm problems.

You do mean the WTS light dont you?

 

 

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I have power to the VP/Lift pump and a WTS so that leads me to believe it's not the ECM. All grounds have been checked/replaced. Are there any suggestions on sensors I maybe be missing that can cause this? I'm replacing the crankshaft position sensor today.

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Still nothing. I will admit its never have an OBD reader connected before and the connection seems a bit sketchy (Power comes on and off if I move the OBD port too much) so unsure if it was even working prior to my current problems.

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23 minutes ago, MrMerica said:

How much pressure should I be seeing out of my injector lines? As you can see in video there’s isn’t much pressure. Not really the crazy “spraying” everyone says to expect.

They spray when you just loosen them a half of a turn or so. You have good flow, the injection event does not need a ton a fuel. The injection event is around 4000 to 4500 psi.

Also the fuel you are seeing there gets pushed thru 7 tiny holes in a split second per event.

 

I had an injector line snap off at the head a couple years back. I ended up clamping some fuel hose on it and ran it to a 5 gallon fuel can in the bed. In the 15 miles back to the job I had near filled that can up with no more flow that you are seeing.

Edited by dripley
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The fuel I saw in your video is coming out of a line with an ID of around 1/16 of an inch, I dont know the exact ID on them. The fuel is being pushed thru 7 holes that are only 100th of an inch in the case of 7 X .010 injectors, 150hp. The injection event happens in milliseconds, how many someone smarter than me would know better. Most injectors should come set near 310 bar pop pressure. 310 X 14.5 psi equals 4,495 psi to pop the injector. 

 

The flow I saw in your vid is pretty much what I have seen out mine with lines loose. I get no spraying from mine since I back the nut all the way off. That being said I have never put my finger over the ends of the lines to feel any pressure they are under. 

Edited by dripley
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Just add this, the line is not under constant pressure. It only ramps for the injection event since we have mechanical injectors.  All of that is done by the VP. Exactly how it does is over my head.

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VP44 is capable of minimum of 4,500 PSI at an idle to well over 20,000 PSI at WOT. If the VP44 PSG is damaged the the fuel pin will not be pulled enough to build pressure. Our VP44 pumps have 3 pistons working in a gang and pump at the same time to the distributor position its currently point at. 

 

 

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  • 2 weeks later...

Found the answer!

 

Turned out to be a dead VP that shorted out and killed a few relays on the way. Replaced the VP/relays and shes back up and running. Looks like the fuel we were seeing in the attached video was actually just lift pump pressure. From what I've gathered if your truck isn't making a mess while cranking with a line completely unseated then you may have a dead VP.

 

Thanks for all the help fellas.

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