95 GMC Yukon No Start/No Spark

[SunlitComet]

yes. if you numbers are correct something is very wrong with it.

 

[DanielP]

I used to own a 1993 truck with a 5.7L and had issues similar to yours. My problem was that the air filter cover would rub on the wires going to the coil which would cause an open short on one of the pigtail wires. I had to replace the same pigtail twice in only a few years. If it won't currently start, you might take off the air filter cover and have someone turn the key over while you jiggle those wires. Hopefully your problem is this simple.

 

[Vette_13]

I have the air cleaner off of it right now but I am going to mess with those wires and jiggle them around..

I replaced the ECT sensor and still have no start

I retested the cool for spark and it is only giving the spark on the initial crank and doesn't after that... I'm stumped

 

[SunlitComet]

any new codes show up? and you did verify proper dizzy install correct?

 

[Vette_13]

Only code that came up was 15 but I figured it was cause I disconnected the sensor to replace it, I cleared the code..

I'm gonna give the dizzy some turns to see if maybe it's off

 

[SunlitComet]

i gotta tel you when i see a one spark start it happens when the ignition system is at fault like a bum coil or im or that the dizzy assembly is screwed up.

 

[Vette_13]

Soooo truck has still not run since... However, today outta the blue I decided to take off the ignition control module from the new distributor and put the OEM one that was on the old dizzy onto the new one and sure enough.. She started right up! Drove it around the block a few times with no issues, turned it off and on a couple different times and it started every time! I'm glad I finally figured this out! Thanks so much for the help!

Now it had a little bit of a rough idle but I'm pretty sure it has to do with a rubber elbow that was on the backside of the throttle body I have no idea what that's called to replace it, it's a vacuum and its wide open now
Opposite of the pcv valve

 

[SunlitComet]

port c is pcv valve, port a is evap canister purge hose, port j is egr and port f is the map sensor.

 

[aliyukonxl]

2003 yukon xl main issue: car starts and runs normal but 20 minutes later it dies out with no spark to plugs (it dies out whether running while parked or while diving at 75 mph) KEEP IN MIND THAT WHEN THE TRUCK IS RUNNING IT RUNS PERFECT NI HESITATION OR PROBLEMS OR MISFIRES IT JUST SUDDENLY DIES OUT
what have i checked so far?
fuel pump good with 40 psi to rails constant
new fuel filter
cam position sensor
crank position sensor (i changed it the first time the car ran fine for two weeks then i started having the same problem so i changed it again)
its driving me crazy i don't wanna waste money on a ecm right now if its not gonna fix my problem

 

[SunlitComet]

your fuel pressure should be in the 50-60psi range so check the power quality to pump and perhaps replace it.