my fuel filter light has been coming on when I'm driving. it comes on around 1,000 rpm and turns off around 1400. i just changed the filter about 2,000 miles ago and it runs fine other than i haven't turned up the new ip to where it should be. fuel pump maybe? i tested the pressure and it was between 3.5 to 5.5. the only other thing is once in a while it is hard starting or will start and run then die when its warm and sits for 45 minutes or so.

 

Could be fuel pump... here's what mine just did:
About 2 weeks ago, was towing a decent load home, and noticed the fuel filter light drift on and off. Watching it, I noticed that it only came on when I was on the throttle pretty far (over half?) but was off as soon as I let up the pedal. Mostly noticeable at higher speeds, but not really when cruising in town. Made a mental note to change filter. Next day with empty truck, didn't notice light at all. A few times over the week it came on when flooring it on the highway, but rarely.

Fast forward to last weekend, went out to breakfast, and stopped at a fuel station on the way back. Drove about 500 yards with the full tank, and the engine just died... Wouldn't restart. Nothing coming out the schrader valve on the filter. Got it towed to a garage I could work in, and swapped the fuel pump (mechanical, not electric). 2nd bout of cranking it fired right up, haven't seen fuel filter light since.

My thoughts are that the pump was on its last legs, and couldn't push as much fuel as the IP wanted at high rpm/high engine loads and that triggered the fuel restriction light. I probably ought to replace the filter too as its getting to be that time, but it wouldn't have changed the situation.