No top end/occassional fuel pump whine

[rendyx]

I've been working on this persistant problem my 91 has with lacking high end power (suddenly runs out of power at about 88mph). I did notice and think about this. It's only happened twice or so, but my Walbro fuel pump will whine a little at startup until I drive for half a minute or so. I also hear a whistle/whine (low pitched, sounds like air rushing) all the time from the rear of the car. That I suspect is my exhaust, which was put together completely with muffler clamps.

I'm not to informed about fuel pressure testing, how should I begin? Must I get a proper gauge, or is it safe to use a tire pressure gauge (if attached well of course)? Thanks!

 

[AutoSHO]

Pat, does the car do this in every gear? Or does it only do it in say, 3rd when you're really laying on it?

To be honest, if its a fuel pressure problem it will probably only manifest itself at speed/under load.

One thing it could be, the early generation cars had a 2-stage fuel pump circuit, perhaps its failing and stepping back to low current to the fuel pump. Thats a very WILD guess, though. I think your best bet might be a fuel pressure gauge from Autometer or VDO or the like, so that you can monitor it driving. I dont think they're much more than a Fuel pressure tester from a parts store ($35).

 

[rendyx]

I haven't done it in 4th or 5th, but in 3rd it struggles to redline, and I believe in 2nd it seems a bit pokey too (might just be my imagination though).