V1 LDK w/z54 loss of power misfires on all 4

[TheNuker]

Hey guys,

Car was running great just crossed 2k miles on the engine. Parked an hour later fired it up and noticed it sounded different. Sure enough when you step on it it just bogs down. I’m struggling to make 70mph in 4th gear holding WOT.

Codes attached. First thing I did was put in 8 gallons of fresh 93 and then I changed the 4 spark plugs with GM oem plugs. Turbo is making boost and if you WOT on the highway it will do some surging and sound normal for a second or 2 before bogging down hard in 3rd and 4th.

Anyone have an idea?
Thanks,
Nuker-

PS don’t mind the code for high/low voltage on coil pack it’s done that since day one.

 

[Gtstorey]

C code is a short to B+ on the power steering feed from the BCM, Not likely to cause a misfire unless it's a symptom of a larger issue.

I don't know that I would count out the P2300 and P2301, It may just have been an occasional problem that has gotten continuous.

But for all cylinder misfire, I would start with fuel pressure. Can you log any live data? HP Tuners?

 

[TheNuker]

C code is a short to B+ on the power steering feed from the BCM, Not likely to cause a misfire unless it's a symptom of a larger issue.

I don't know that I would count out the P2300 and P2301, It may just have been an occasional problem that has gotten continuous.

But for all cylinder misfire, I would start with fuel pressure. Can you log any live data? HP Tuners?

Yeah hoping to do that tomorrow with the laptop, I’ll post the logs as soon as I can. Thanks!

 

[TheNuker]

Well, I unplugged the MAF and its running like a champ. So I guess I have my answer.

Nuker-

 

[Gtstorey]

Did you ever log anything in HPT? It would be interesting to see if it flat lines or is just showing bogus data.

 

[Goblinfanclub1234]

were you parked in a public spot before it started? could someone have sabotaged something like switching around some plugs or something.

MAF took a dump = cheap fix

 

[Chubbs]

A while ago while decelerating for a highway off ramp, I blipped the throttle for a downshift and something "popped' just a bit. It sounded different, just as you describe. I eventually found a vacuum line on the intake manifold that had blown off. I put it back on with a zip tie for a little extra insurance, and it's been fine ever since.

I have no idea if that's what happened to yours, but it certainly sounds similar. Make sure you don't have any hoses dangling.