Hi folks, long time no see. Well the engine is running like total **** out of the blue again. So here are the symptoms:
-Starts fine and quickly revs to around 1200RPM for a second or so, then falls to 500 RPM. It then stumbles a bit then starts to idle okay at 900RPM
-Driving up a slightly inclined driveway, it stumbles and bucks and struggles to just make it to the street.
-Driving on the street, it stumbles badly especially between shifts (6-speed). So every shift has a significant stumble, especially at lower RPMs.
-Firing on it and revving to 6200RPM, it stumbles and just runs like total crap. It is definitely lacking power and consistency.

Things I have recently done.
-Replace plugs with TR55. The number 8 plug previously died so I replaced them all. I determined it was dead due to a cold #8 header primary.
-Currently has a 4year old Petras Opti.
-Just replaced the fuel filter. Old one seemed fine.
-All eight primaries produce heat shortly after startup, so I am assuming we have fire on all 8.

I have generally forgotten all of the LT1 troubleshooting steps over the years. Attached is a Datamaster data log for a 5-minute road test. It has typical driving and a couple of high RPM launches. Hopefully, something stands out. Thanks in advance for taking a look.

 

Oh, Maybe I am misreading. But the BLMs may not be locking at 128/128 at WOT. My gut tells me it may be a fueling issue. Could be wrong.

 

Have you verified fuel pressure?
Are your spark plug wires burnt or cracked?

 

Okay I had to get a new fuel pressure gauge. Looks like I only have 32# at warm idle, and if I remove the vacuum hose from the FPR, the pressure remains the exact same. I replaced thew fuel filter, no improvement.

Is this the pump? Maybe the FPR? Other?

 

Did gas come out of the vacuum line?

 

I put the new FPR on. Same issue with pressure about 30#. Looking like the pump is petering out considering that when the rail is empty and the key is turned on, the pressure builds very slowly. I intend to look for fuel line damage underneath first.

Okay, so who offers a quality replacement fuel pump?

 

Pretty sure this will work.
https://www.summitracing.com/parts/vpn-gca758-2
Intake may not match that of the fuel pump bucket, but you can cut the inner ribs off to make it fit, and if you don't have a bucket, you need one to help keep the pump cool.

 

Pretty sure this one comes with a bucket. I like the connections and doesn't use rubber lines that can kink.

https://www.tickperformance.com/race...-97-lt1-fbody/