Here's a tough one for you guys...

my fuel pump has always been pretty loud and whiney (walbro 255), so when I heard it get louder I just thought it was time for a new pump, but then I realized it was the new sound was coming from the engine bay.

I've driven it a few time sense trying to diagnose it with no luck...

so far I've got this:
- it only happens when it's warm
- it seems dependent on engine load (if I move the pedal it changes tone, sometimes it seems to go away entirely)
- it seems to be either coming from the back of the engine or underneath the intake manifold, but it's hard to pin point.
- it's pretty loud now, you can here it from like 50 feet away.
- it's still there when I have the clutch out or in, so I don't think it's a clutch bearing

any ideas?

 

Walbro whine from the rails? Maybe try pulling the vacuum line off the FPR to change fuel pressure. If it's pump related, flow and sound should change. Other than that I would suspect pulleys bearings, pumps, etc...

 

I also discovered my injector bleeds came unplugged... does anyone know if they make a high pitched whining noise when they're open?

 

I'm gonna go for Clutch now. Whats your setup? Pop the cover on the bottom of the bellhousing, see if it's there.

My new flywheel whines like crazy, it's high pitched like you described, depending on engine load. Maybe something in the came loose.

 

ACT xtreme pressure plate with an ACT performance street disc and a ACT prolite flywheel...

how long has yours been whining?

 

Since I first turned the car on.
It's got a bunch of holes in the flywheel. It increases and decreases with RPM.
Tilton Twin disc clutch/flywheel combo. It's a lot harder to drive than I thought it would be.

I'd definately pop that bellhousing plate and give it a listen.

 

Did you check it out yet?

 

nah, i ran into issues with my corolla's rear disc brake conversion... I'll look at it when I get home today though, outside in the parking lot if I have to.