Weak pump and clogged filter symptoms

What are weak fuel pump, clogged charcoal canister and clogged fuel filter symptoms?

If I said to you Guess?? What would you think??


Low pressure that won't rise with boost 1-1lb comes to my mind.
How can a clogged weak pump keep proper pressure especially under boost??
 
clogged filter OR weak pump not a clogged weak pump. Do weak pumps still show full pressure at idle usually
 
yes and no. a weak pump usally stats to lose that 1:1 rise at higher pressures
 
Plugged cannister will shut off the tank vent, causing a vac to be drawn on the tank. The vacuum will cause pump cavitation, pump failure.
 
You need a fuel guage you can read while under boost. 3ft of hose taped under the windshield arm is the cheapest way. An electric from Autometer is $200 but nice to have. Can also be hooked to Power Logger to record & playback later.
 
The time my fuel pump went weak I couldn't get boost past 5 psi without knock. On the fuel pressure gauge it would go up to 46-47 psi and then would suddenly drop off if I tried to push it any harder. Other than that typical driving around not getting in the boost was fine. The pump even showed a steady 42 psi at idle w/o a vacuum on it. (i.e. vac line removed) Replaced the pump (it turned out to be one of the notoriously defective F2000169 pumps) with a newer Racetronix Walbro pump but still had issues with fuel pressure dropping off, except now at 52-53 psi instead of 46-47 psi. Changed out the fuel filter and all was good again.
 
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