not your typical crank but won't start

[rob_z71]

i seem to be stumped here. truck is a 1998 gmc k1500 5.7 that was running perfectly fine until i tried to fire her up the other day and she just cranks and wont start. here's on overview of whats wrong/things i've tried:
-little to no fuel pressure
-no spark
-tach doesnt move while cranking
-fuel gauge is pegged way past full
-all fuses are fine
-swapped relays around where i could
-*check engine light isnt illuminated on dash with rest of lights with key in on position*
-*my scanner cannot connect to the truck as if the key isnt on while ive got it plugged in to the obdII*
-i've replace the crank position sensor on the advice of a mechanic buddy and still wont start
-i've visually checked all wires i could see for visible breaks
-the coil has juice going to it - checked with power probe
-fuel pump is an OE replacement from a year ago
-whole distributor was replaced a couple of years ago(obviously including ICM which guys said could cause this problem)

if you guys have any info at all please feel free to leave it. i use this truck every day to get to classes and work. thank you

_Rob

 

[Breakdown]

Almost sounds like a bad ECU... or possbly an ignition switch problem. Does your truck have vehicle anti-theft maybe?

 

[rob_z71]

Almost sounds like a bad ECU... or possbly an ignition switch problem. Does your truck have vehicle anti-theft maybe?

thanks for your response. im thinking it's potentially the computer as well. theres no anti theft on the truck

 

[Breakdown]

As an experiment go snag an Ecu from the local bone yard that matches the make and model of the truck you have. Even if the tune isn't exactly what you have you should be able to get it to start after swapping.

 

[rob_z71]

As an experiment go snag an Ecu from the local bone yard that matches the make and model of the truck you have. Even if the tune isn't exactly what you have you should be able to get it to start after swapping.

Well I did the 411 swap about half a year ago so I'm in contact with the guy I got it from to see if he'll work with me since I've somewhat narrowed it down the to ECU. I'm just worried about what happens if he sends me another one and I pop it in and have the same problem. Only thing I was ever able to find online with the same symptoms is some Toyota that had a tab break off inside a connector and was shorting out two pins or something which can't be my cause because I've gone over just about everything

 

[df2x4]

theres no anti theft on the truck

If you haven't tuned the computer to remove it, there actually is the factory GM PassLock anti-theft. '98 was the first year that was implemented. Not sure if it has anything to do with your issue, just something to be aware of.

 

[rob_z71]

If you haven't tuned the computer to remove it, there actually is the factory GM PassLock anti-theft. '98 was the first year that was implemented. Not sure if it has anything to do with your issue, just something to be aware of.

Yeah the computer is fully tuned to. Thanks for the info

 

[Eric1234]

Im not sure if I'm in the right place for this if not I'm sorry. I'm having some issues with a 92 k1500 5.7l truck. I was having a idling issue where it surged very bad till the motor would quit surging worse as the motor got warm. I've replaced the distributor cap and button icm coil iac valve tps fuel filter and the coolant temp sensor. Every time I worked on the truck the idle seemed to get worse now the truck won't start no fire no fuel yesterday I was able to get the truck started with ether but only ran with my foot on gas peddle the injectors sprayed fine and the truck would almost immediately die at idle. I have no clue what else to do or could be wrong any help would be greatly appreciated

 

[Bob L]

To the OP I was playing with ground straps this week and both mine from the frame to the firewall and from frame to rear of the rt. head just fell apart when I touched them. Truck wouldn't start after until I replaced them

 

[96_NorthernChevy]

i seem to be stumped here. truck is a 1998 gmc k1500 5.7 that was running perfectly fine until i tried to fire her up the other day and she just cranks and wont start. here's on overview of whats wrong/things i've tried:
-little to no fuel pressure
-no spark
-tach doesnt move while cranking
-fuel gauge is pegged way past full
-all fuses are fine
-swapped relays around where i could
-*check engine light isnt illuminated on dash with rest of lights with key in on position*
-*my scanner cannot connect to the truck as if the key isnt on while ive got it plugged in to the obdII*
-i've replace the crank position sensor on the advice of a mechanic buddy and still wont start
-i've visually checked all wires i could see for visible breaks
-the coil has juice going to it - checked with power probe
-fuel pump is an OE replacement from a year ago
-whole distributor was replaced a couple of years ago(obviously including ICM which guys said could cause this problem)

if you guys have any info at all please feel free to leave it. i use this truck every day to get to classes and work. thank you

_Rob

Yeah the computer is fully tuned to. Thanks for the info

are you getting any life if you shoot a bit of starting fluid and cranking?