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Complete Newbie at a loss... 97 8.0L won’t start

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Old Mar 11, 2018 | 08:05 PM
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Default Complete Newbie at a loss... 97 8.0L won’t start

I’m throwing the book at this truck and running out of ideas. Bought the truck 2 months ago, have since done plugs and wires and a fuel pump. Fuel pump was just changed last week. Up until yesterday the truck was running, but at an idle the rpms would fluctuate. Started driving down the road and truck acted like it was falling on its face when I stepped on the gas. Truck stalled out and hasn’t started since.
So far things I’ve checked are:
there is spark at all the plugs
fuel pressure at the fuel rail is 40 in the on position and 50 while trying to start.
used a noid light on the rail and the injectors are getting signal
used an ohm reader and tested the crank and cam sensors. According to what I’ve read they are on a 5amp circuit and should read at about 5 amps dropping to just above zero when starting. Both do just that
ASD relay is good
All fuses seem to be good
Disconnected the battery for 20 min to drain system

I’ve run out of ideas, can use any advice I can get!
Thanks in advance!!!
 
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Old Mar 11, 2018 | 08:07 PM
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Are you getting spark? Check two cylinder on each set of coils. (one set does six cylinders, the other set does four.)
 
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Old Mar 11, 2018 | 08:14 PM
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I used a screw driver and the block to check spark at the plug end of the wires and I have spark
 
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Old Mar 11, 2018 | 08:35 PM
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Originally Posted by HeyYou
Are you getting spark? Check two cylinder on each set of coils. (one set does six cylinders, the other set does four.)
Also, no check engine light, but threw a P0172 code on the scanner. Told that could be from trying to start it so many times
 
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Old Mar 11, 2018 | 10:12 PM
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Could be from just cranking it, or, could be an injector problem.... If you stomp the gas pedal to the floor, and crank it, do you get any action? Does the engine ever even try to start?
 
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Old Mar 11, 2018 | 10:17 PM
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Originally Posted by HeyYou
Could be from just cranking it, or, could be an injector problem.... If you stomp the gas pedal to the floor, and crank it, do you get any action? Does the engine ever even try to start?
it tries to start, but never actually turns over. No different results stomping the gas as from just cranking.
 
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Old Mar 11, 2018 | 10:19 PM
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If you have good spark, then it's likely a fuel problem. Verify fuel pressure, and injector pulse. You should be able to rent the tools from your local parts store.

What brand fuel pump did you put in?
 
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Old Mar 11, 2018 | 10:21 PM
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Originally Posted by HeyYou
Could be from just cranking it, or, could be an injector problem.... If you stomp the gas pedal to the floor, and crank it, do you get any action? Does the engine ever even try to start?
the fuel injectors are getting signal, but will check to be sure the injectors are working tomorrow
 
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Old Mar 11, 2018 | 10:28 PM
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Originally Posted by HeyYou
If you have good spark, then it's likely a fuel problem. Verify fuel pressure, and injector pulse. You should be able to rent the tools from your local parts store.

What brand fuel pump did you put in?
fuel pressure at the rail is 40 psi in running position and 50 psi in start position. Rented a noid light and checked the signal to the injectors. Signal is intermittent with the pulse of the motor trying to turn over.
Im almost certain it was a Delphi pump
 
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Old Mar 11, 2018 | 10:38 PM
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Is that just a bad connection on the noid light? Or is the cam sensor failing?
 
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