[JcLusso]

So I've run into a very confusing problem. 2 nights ago I filled up about 40/60 E85/ 93 and the car was running great. Drove through about 4 gallons. Parked the car and the next day I fixed my battery cable issue that I had. The cable was frayed and was causing charge issue and was only putting about 12-12.5v to the battery.All went fine with that. I rehooked the battery back up and all of a sudden I have this crazy odd issue. If I floor the car it won't rev past 3k-4k and will start misfiring or atleast sounds like misfiring. I have thrown some random misfire codes across different cylinders.

1. I don't believe I have a vacuum leak because i unplugged a line after the car was off for a while and I heard vacuum. I also can hear a clear difference when unhooking a vacuum line while the car is on

2. It seems almost like traction control limiting and it doesn't throw misfire codes all the time. It just sounds like it sorta.

3. It builds boost and you can hear it clearly.

4. I can rev the car to 5-6k if I gradually increase it and it sounds fine. It's only if I floor it.

Any ideas?

Update w/ Codes
2E0F: No description and have had for weeks prior... car was running fine with it

2BE9: Fuel pressure: Pressure below minimum pressure; injection deactivation for catalytic

2C90: Blow-off valve, mechanics: Jammed closed (read a while back that this code is normal with JB4 hooked up.)

2C58: Boost pressure control, deactivation: Boost- pressure build-up blocked

[scflaw]

I'm pretty sure somebody would ask the same question.
Mod list?
Tune or supporting hardware for ethanol?

[JcLusso]

Jb4, FBO + Meth. Ran half of the gas out and tried unhooking jb4. Still have issues. Here's a video.

[JcLusso]

Update w/ Codes
2E0F: No description and have had for weeks prior... car was running fine with it

2BE9: Fuel pressure: Pressure below minimum pressure; injection deactivation for catalytic

2C90: Blow-off valve, mechanics: Jammed closed (read a while back that this code is normal with JB4 hooked up.)

2C58: Boost pressure control, deactivation: Boost- pressure build-up blocked

[.mark]

Honestly I'd double check your battery cable first..sounds like you may be having some power issues.

[JcLusso]

Hidden OB menu reads 14v solid....

Originally Posted by .mark

Honestly I'd double check your battery cable first..sounds like you may be having some power issues.

[.mark]

Originally Posted by JcLusso

Hidden OB menu reads 14v solid....

At idle or with a load on it?

[JcLusso]

Both. If I rev it to 6k slowly it gets there fine. If I try and push the car to accelerate it just chokes.... or if I rev it in neutral. It's like something is limiting it almost in my opinion.

[bk335ilci]

Hpfp??

[JcLusso]

Originally Posted by bk335ilci

Hpfp??

Wouldn't I have startup issues and long cranks. Car runs fine at idle and startup

[bk335ilci]

Doesn't the hpfp work off of the rpm because it is gear driven. Do some logs and ask Terry?

[JcLusso]

I don't think its the HPFP. HPFP is very common on N54 but I'm N55. Also, car show no signs of long cranks or rough idle...

[thomas88162]

Yet you have a pressure deviation code... Even some N55's occasionally reject HPFP's.

[JcLusso]

Originally Posted by thomas88162

Yet you have a pressure deviation code... Even some N55's occasionally reject HPFP's.

Wouldn't HPFP be more sporadic. Like I figured car would randomly have start issues, almost die out and stuff like that. Did you see the video about? It's so identical every time and just makes me feel like its something electronic restricting it almost...

[SUPAN]

Ignition coil changed ? spark plugs ?

[JcLusso]

Originally Posted by thomas88162

Yet you have a pressure deviation code... Even some N55's occasionally reject HPFP's.

Had my friend check it out and his computer diagnosed HPFP.... symptoms make sense too now. Also, the issue has worsened and it won't rev past like 2k now.

[JcLusso]

Anyone have a guide on replacing the HPFP for N55. Found a N54 DIY.... but no N55

[bk335ilci]

How many miles on your car? And how many were you tuned for?

[JcLusso]

Originally Posted by bk335ilci

How many miles on your car? And how many were you tuned for?

49k. Tuned since 10-12k w/ JB4 + FBO. Started running meth around 43k and mixing E85 around 47k.

[JcLusso]

Turns out something else still must be wrong since the HPFP was replaced and I'm still having this issue....

[RyanMv4]

Any update on this ? Same exact thing happened to me today

[JcLusso]

Originally Posted by RyanMv4

Any update on this ? Same exact thing happened to me today

No idea. It went away after sometime and didn't return. When it would happen id power car off and then back on really fast and it would just go away. Sometimes would take a few on/off tries.