Misfiring and stalling no codes please help.

[justin_48]

I need some help guys. I have a 2005 hoe with 284xxx miles on it and it's been super reliable however it left me stranded a couple weeks ago. Started shuddering when driveing pulled off on the side of the road and it stalled out. It seemed like a fuel issue and immediately blamed the cheapo fuel pump so replaced it. Got about 8 min down the road from home started missing again and died. Went home and got a fuel pressure guage and was 60psi and will run great but then will eventually miss and die.
-Plugged up all the vacuum ports on the intake to see if it had a vacuum leak, still dies. It's a non return fuel rail so no fuel pressure regulator.
-Swapped maf with my 2000 siverados, still same runs fine then misfire and dies.
-Saw posts about crank position sensors going interment bad. Put a new one in did the crank learn. Still will miss and die.
-Did intake manifold gaskets. Still miss and die.
‐Did upstream o2 sensors as a buddy looked at my log and saw one that seemed to drop off and was slow. Still miss and die.
-Cleaned the ecm ground on the back of passenger head and frame grounds under drivers door. Still miss and dies.
-Put new plugs in. Still will miss and die.

Attached is my log in the zip file from cold start to stall out for someone to see something that I am missing.

 

[Joseph Garcia]

Welcome to the Forum from NH.

Lots of knowledgeable folks here who freely share their knowledge, experiences, and perspectives. Knowledge is power.

I hope that you will become a participating member in the Forum's discussions.

Pics of the truck, please.

I cannot personally help you with your question; however, other members on this Forum that are much more knowledgeable than me in this area will chime in.

 

[justin_48]

Welcome to the Forum from NH.

Lots of knowledgeable folks here who freely share their knowledge, experiences, and perspectives. Knowledge is power.

I hope that you will become a participating member in the Forum's discussions.

Pics of the truck, please.

I cannot personally help you with your question; however, other members on this Forum that are much more knowledgeable than me in this area will chime in.

Thanks for the welcome! This is my 05 tahoe that I got 3 ish years ago. Had some work needed when I got it but most of it was cosmetic. Hope to help out the best I can!

 

[swathdiver]

Does the fuel pressure remain constant when the misfires begin until it stalls? What do the plugs look like?

 

[justin_48]

Does the fuel pressure remain constant when the misfires begin until it stalls? What do the plugs look like?

Yes the fuel pressure remains constant. 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.

 

[swathdiver]

Yes the fuel pressure remains constant. 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.

How does this plug look to you guys? Normal to a little lean? Is it time yet for a compression test?

@gooffeyguy @iamdub @Doubeleive

 

[Doubeleive]

How does this plug look to you guys? Normal to a little lean? Is it time yet for a compression test?

@gooffeyguy @iamdub @Doubeleive

Plug looks good to me, just like mine have looked before

 

[justin_48]

Yes the fuel pressure remains constant. 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.

Also forgot to mention I pulled the upstream o2s and left them disconnected and started it as people where saying possible plugged cats. Still ran normal for about 2-3 mins then started misfiring and stalled out. Felt a decent amount of exhaust from the o2 bungs and then checked the tail pipe and still felt some exhaust less than normal but I expected that due to the o2s being out. I would have pulled the y pipe but the nuts wouldn't loosen from the manifolds with my 1/2 impact and the breaker bar was at the "gunna snap this stud..." I didn't want to snap them and go through the repair if it didn't improve anything with the o2s out.

 

[Donal]

Yes the fuel pressure remains constant. 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.

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?

 

[Doubeleive]

any changes if you swap coils around? checked the coil harness? if everything else checks good I would start looking at electrical
sounds like it is ok while cold?
hook up a noid light while it is missing and see what coils/injectors are doing

 

[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