2012 Yukon Denali

[petethepug]

Have you swapped a plug wire yet or just the coil?


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[Spookus]

Have you swapped a plug wire yet or just the coil?


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I have swapped, coils, spark pugs, plug wires, and am currently swapping injectors from #5 to #7. If that doesn’t make a difference I don’t know what my problem could be.

 

[Spookus]

Ok, so I’ve swapped everything off #7. Coil, plug, wire, and injector for a brand new one. Drive fine for a while, but after awhile it starts misfiring. I even changed the lifter oil filter. I have no idea what is making this thing misfire. I have no more electrical problems, nothing is flashing anymore. Just the misfire. Does anyone have any ideas. I’m about to take it to the dealership and have them look at it.

 

[kbuskill]

Ok, so I’ve swapped everything off #7. Coil, plug, wire, and injector for a brand new one. Drive fine for a while, but after awhile it starts misfiring. I even changed the lifter oil filter. I have no idea what is making this thing misfire. I have no more electrical problems, nothing is flashing anymore. Just the misfire. Does anyone have any ideas. I’m about to take it to the dealership and have them look at it.

When you say it drives fine for a while... can you define "a while"???

Does it run fine until it is up to operating temperature or does it run fine even after being at operating temperature for a while and then start to misfire?

Can you feel the misfire or is it just showing up on a scan tool?

 

[Spookus]

When you say it drives fine for a while... can you define "a while"???

Does it run fine until it is up to operating temperature or does it run fine even after being at operating temperature for a while and then start to misfire?

Can you feel the misfire or is it just showing up on a scan tool?

When I say “awhile” guess I mean sometimes it’s 20minutes driving around town and the highways, some times it’s an hour or so. It goes away for awhile and doesn’t misfire, then all of a sudden it’s back to misfiring. You can feel it, when it happens at idle you can feel the car shake. Could the VLOM solenoid be bad?

 

[kbuskill]

It's very possible.

 

[gooffeyguy]

How old is the fuel pump?

2001 Yukon SLT
2012 Yukon Denali XL
2011 Yukon Denali RIP 5/20/18

 

[Spookus]

How old is the fuel pump?

2001 Yukon SLT
2012 Yukon Denali XL
2011 Yukon Denali RIP 5/20/18

I have no idea. As far as I know it’s the original pump.

 

[gooffeyguy]

A couple weeks before the fuel pump went out on my 2001 it felt like it would misfire bad at times. Wasn't sure what it was, then one day the engine cut out for a few seconds while driving then came back on. Got it home and went to mess with it a bit later and it wouldn't start.

2001 Yukon SLT
2012 Yukon Denali XL
2011 Yukon Denali RIP 5/20/18

 

[Spookus]

I took the Denali to the dealer today. I drove it all day yesterday and didn’t get a single misfire everything ran great. I started the car this morning and the remote start wouldn’t work, it would try to start it and die. But would start with key no problem. But all the electrical issues started again, gauges dropping to O then bouncing back up, blind spot freaking out, door locks going on and off, Traction and Stabilitrac lights on. Radio never quit, didn’t want to shift to save it’s life, had to put it in manual. About half way into the drive the line underneath the M was gone and it didn’t say what gear I was in. So I had to put it back into drive. Got to the dealership showed them what it was doing and he said my Bluetooth OBS2 scanner could be messing it up. So I unplugged it and within a seconds it all went away except the Traction, Stabilitrac, and Check Engine Lights. Anyone ever heard of this?