I've had this problem for close to a year now.
On two different engines..
Still haven't figured it out.
Atleast one out of every three times I drive my car it'll lose power and then act like its hitting a limiter (guessing its either not getting enough or getting too much fuel).
At first I thought it was just from where my engine was blown.
New engine, same problems.
Removed whole emissions rack, blocked everything off, ran new fuel lines.
Same problem.
Rechecked for vac leaks and still nothing.
The fuel filter has maybe 5,000 miles on it so I figured it was still fine.
I'm thinking possibly the fuel pump strainer/filter?

Its only with a load on the engine, in neutral I can rev to whatever I want...
Just thought I'd see what you guys thought it MIGHT be....
=/

 

Update: Replaced the fuel sock. I could tell a little bit of a difference at first, and then realized I don't have a lot of gas. It kept doing the same thing, but I'm hoping its just because I was low on gas.
I'm hoping to fill it up tmrw after I weed-eat and see what it does.
Worst case scenario my walboro 255 burnt out..
Anybody have a n/a fuel pump that'd want to give me if I paid shipping?
I lost my jerb... lol :'(

 

Have you checked your secondary injectors? My 7 was doing that for a while so I just made sure they were clipped on right and made sure the fuel pump relay was connected properly and it hasn't happened again.

 

MOP limp?

 

I checked my secondary injectors a while back, but I will double check them today.
I haven't seen the engine light come on and I've checked for codes a few times with and without the car running.
Nothing, I also just replaced the ecu and the MOP last month.
At the same time and checked the MOP and the ecu to make sure both were good. =(
Also, now I've noticed if I'm a 1/4 tank or less the engine cuts out so another problem shows...
Rusted tank baffles.. wee rusty 7's.

 

Check that fuel pump relay under the dash.

 

Fuel pump relay is unplugged and is a non-issue since the fuel pump is hot-wired.
It got fried a while back.
This was probably 5 or 6 months after the problem I'm having started.
However, I noticed today that w/ the clean fuel sock it does run much better and the walbro is quiet.. for a walbro.
After 5 minutes of driving you can hear the walbro outside of the car and about 20 feet away. This is over a streetported 13b w/ no exhaust (at the time).
Also, I let someone else drive the car while I sat in the hatch (lulz) and listened to the pump.
I could hear the pump acting up.. I'm putting all my money on a burnt out walbro slowly dieing over a year.....