07 escalade p0300 and stabilitrac light on running rough

[rcsnipe2000]

hey all, long time lurker, 1st time posting

i have a 07 escalade with a 6.2. i have a hard miss on #6. (used tech 2 for pulling the code) p0300

i have swapped 2 injectors to see if it went to the new hole. no luck

i have good spark at the plug (use a spark tester at the plug and coil wire) good spark

i have sprayed brake clean around the intake and no leaks found there.

i have good fuel pressure. 58ish on the fuel pressure gauge

i dove this car around yesterday with no probs. even topped off the tank. this morning, this happens.

any ideas? anyone ever have this happen just out of the blue?

thanks for any help,
rc

 

[89Suburban]

How many miles on it? Did you pull the actual spark plug to inspect?

 

[rcsnipe2000]

hi, 210k on it. pulled the plug and it was clean. no fuel on it at all.

rc

 

[89Suburban]

hi, 210k on it. pulled the plug and it was clean. no fuel on it at all.

rc

Time for a compression test or knock off the valve cover and check the rockers on that cylinder. No funny noises? Hopefully others will chime in here.

 

[rcsnipe2000]

yes, thats what the plan is for tommarra. see what the compression is. as far as valve noise, i dont really hear anything suspect.

rc

 

[89Suburban]

yes, thats what the plan is for tommarra. see what the compression is. as far as valve noise, i dont really hear anything suspect.

rc

Good luck hoss.

 

[Joseph Garcia]

Keep us updated, and we'll help out where we can.

 

[rcsnipe2000]

ok fellas,

again, my prob is a hard miss fire on #6.

so, today i pulled the valve cover and all the lifters and rockers are working with no play in them. so no stuck lifter for sure.

i did a compression test on #6 and it is at 160. so pleanty of compression there.

i did look through the spark plug hole while i had the plug out with a snap on video borascope. i could see a bit of a carbon ring around the top of the cyclender and some carbon build up on the top of the piston. nothing that screams we have a problem, but enough to go ahead and do a de carbon on the engine. so i put a can in and im letting it sit over night for a good soak.

anything yall can think of to check, please let me know.

 

[Geotrash]

ok fellas,

again, my prob is a hard miss fire on #6.

so, today i pulled the valve cover and all the lifters and rockers are working with no play in them. so no stuck lifter for sure.

i did a compression test on #6 and it is at 160. so pleanty of compression there.

i did look through the spark plug hole while i had the plug out with a snap on video borascope. i could see a bit of a carbon ring around the top of the cyclender and some carbon build up on the top of the piston. nothing that screams we have a problem, but enough to go ahead and do a de carbon on the engine. so i put a can in and im letting it sit over night for a good soak.

anything yall can think of to check, please let me know.

I would try swapping coils and plug wires also and see if the problem follows. I've seen coils produce a spark at starter speeds but fail to deliver reliably at engine speeds. I've also had an injector connector come loose and produce a misfire. Hit it with electrical contact cleaner and reseat it firmly to be sure.

 

[rcsnipe2000]

yes, i forgot to mention i did swap the coil and plug wire to #2 and the injector with #4. i still have a #6 miss fire. nothing moved to another cylender after the swap. it stayed the same