VIDEO Running lean/engine stutter under load 2-4k rpm

[rcfanatic]

This is a continuation of the following thread, except the problem has gotten worse:

http://www.r3vlimited.com/board/showthread.php?t=270550

Now the engine leans out from 2-4K, although for the first time it leaned out over almost the entire rev range. AFR is 18-19 under load. Here is a video of the fuel pressure with a new AFM installed. The new AFM did not change the symptoms.

http://www.youtube.com/watch?v=nyl_JhZ5hPE&feature=youtu.be

The video quality is not the best. The pressure it is moving around is 40psi. It increases to 45psi at full throttle. Is this sufficient? The needle can be seen shaking a lot when I accelerate again from the 25-40 second mark. Could my fuel pressure regulator be bad? A new fuel pump was just installed 2 months ago and did not change the symptoms either.

Any thoughts, suggestions appreciated. Need to make a trip for a job interview in a couple weeks but can't run the car lean like this at fear of damaging the engine. I'm trying to get this worked out before then so I don't have to rent a car. Thanks!

[rcfanatic]

Well things just went from bad to crisis. Sounds like I have top end damage :(

https://www.youtube.com/watch?v=vuXFncQ_Qng

https://www.youtube.com/watch?v=LF_4x4q5K94

[SmokeE30]

idk about the lean condition but that thing sounds like it has a broke rocker or something, pop of the valve cover and see whats up.

[jlevie]

43psi at full throttle (or with the FPR vacuum line disconnected) would be normal under a closed throttle it will go down to ~37psi. I can't read the gauge well enough in the video to be certain, but it doesn't look like there is a fuel pressure problem.

An AFR of 18-19 is way lean. With the rail pressure being about normal for the engine to be running that lean the suspects are the injectors, AFM, the DME, or a massive intake leak. The video in the second post of the engine idling tends to rule out intake leaks. Injectors are a possibility, but that usually results in a very rough idle. Looking at your other thread and what has been replaced I'm thinking a bad DME.

The sound the engine is making sounds like a rod bearing to me.