Misfiring and stalling no codes please help.

[gooffeyguy]

Have you checked for any trouble codes?

 

[Fless]

All the plugs looked like this. Put a new set in gapped at .040 as the old ones where at .053. Didn't improve anything with new plugs.

That one you pulled out looks like a copper plug and the center electrode is worn and rounded; I don't see any platinum or iridium tips. Having said that, what make and number plugs did you replace them with?

 

[justin_48]

I would probably do an injector flow balance test. Does the wide open throttle acceleration, from stopped, feel normal? Does your fuel pressure tester allow for metered release? have you tried operating with out the air filter and verified no obstruction in the intake air system?

That one you pulled out looks like a copper plug and the center electrode is worn and rounded; I don't see any platinum or iridium tips. Having said that, what make and number plugs did you replace them with?

Yeah they where copper plugs I put some autolight single platinum AP5245 in gapped at .040.

I appreciate all the help guys and sorry for the delay was out fixing the ac on my silverado and then dove back on my tahoe.

Was going to try a wot test in the driveway to see what power was like and this is what happen. So new issue I found out truck started misfires right away put in reverse moved 3 feet, shut down. Crank no start. Noticed the check engine light not coming on when first turning key on. Pulled coil wire no spark. Exhaust smells like raw fuel. Cycle key keep trying and eventually fired up and the check engine light worked watched pulled plug wire when running the spark goes away when stalling. Now back to a crank no start no spark and raw fuel smell out exhaust. Hp tuner data log says trying to give 12* of timeing. Am I wrong but I thought that the check engine light is supposed to come on key on engine off for a lamp test/ecu wakeup indicator. But how is hp tuners seeing data if ecu is "not waking up" and injectors are fireing?

 

[Donal]

Yeah they where copper plugs I put some autolight single platinum AP5245 in gapped at .040.

I appreciate all the help guys and sorry for the delay was out fixing the ac on my silverado and then dove back on my tahoe.

Was going to try a wot test in the driveway to see what power was like and this is what happen. So new issue I found out truck started misfires right away put in reverse moved 3 feet, shut down. Crank no start. Noticed the check engine light not coming on when first turning key on. Pulled coil wire no spark. Exhaust smells like raw fuel. Cycle key keep trying and eventually fired up and the check engine light worked watched pulled plug wire when running the spark goes away when stalling. Now back to a crank no start no spark and raw fuel smell out exhaust. Hp tuner data log says trying to give 12* of timeing. Am I wrong but I thought that the check engine light is supposed to come on key on engine off for a lamp test/ecu wakeup indicator. But how is hp tuners seeing data if ecu is "not waking up" and injectors are fireing?

Such chaotic operating conditions can be caused by power and ground circuits being intermitted connected, damaged, corroded, incorrect component installed and 318 other conditions. Execute the fundamentals. Search for bare wires, corroded connections, disconnect. clean, verify components are correct for this vehicle.

 

[justin_48]

Such chaotic operating conditions can be caused by power and ground circuits being intermitted connected, damaged, corroded, incorrect component installed and 318 other conditions. Execute the fundamentals. Search for bare wires, corroded connections, disconnect. clean, verify components are correct for this vehicle.

*Fixed!* Found out was the coil ground wire that all the coils share is on the side of the block where the battery ground goes. Gave it a little tug and snap! Oh by the way autozone has free wireing diagrams! If you click manage vehicles they have "repair guides " and a crap ton of wireing diagrams in there.Thank everyone who have been giving me ideas and things to try! This was the most frustrating thing to try to diagnose. Guess as time was going on and the engine shaking from the misfires is when the strands just kept breaking until finally couldn't get ground readings on the coil plug. I just don't understand why they would put such a small wire down there when they could have used the ecm ground way up by the harness on the back of the right head .

 

[Doubeleive]

*Fixed!* Found out was the coil ground wire that all the coils share is on the side of the block where the battery ground goes. Gave it a little tug and snap! Oh by the way autozone has free wireing diagrams! If you click manage vehicles they have "repair guides " and a crap ton of wireing diagrams in there.Thank everyone who have been giving me ideas and things to try! This was the most frustrating thing to try to diagnose. Guess as time was going on and the engine shaking from the misfires is when the strands just kept breaking until finally couldn't get ground readings on the coil plug. I just don't understand why they would put such a small wire down there when they could have used the ecm ground way up by the harness on the back of the right head .

hah, nailed it.
the coil harness is known to sometimes develop a bad ground, if you ever get a no start/no spark and everything else checks out, check that ground if bad you can just ground it to the block to get you going again