A while back the in-tank fuel pump in my '91 Chevy Silverado failed, and I replaced it. The truck started right up first time afterwards, but since then the fuel injectors (they’re throttle-body type, two of them) make noise; I can hear the solenoids that open and close them when the truck is idling, and I can hear the noise change when I play with the throttle. The truck runs fine, performance and fuel efficiency are what they should be. Why are they suddenly making noise?
Is the voltage supplied to the injectors within spec.?
I have no idea. Nothing else other than the fuel pump was changed.
Then the problem must be related to the fuel pump change,are the fuel pressure specs. within range?
Consider a possibility of a problem unrelated to the fuel pump change,or a problem related to perception.
I haven’t checked that, and I don’t think I have a proper gauge to do that with. There’s a pressure regulator on the TBI and excess fuel is returned to the tank. If the pressure was too low, then it wouldn’t run (or at least wouldn’t perform properly at highway speeds, which isn’t the case). What would be the typical symptoms if the pressure was too high for some reason?
If fuel pressure is to high a strong fuel odor is emitted and the engine runs to rich.
Most fuel injectors will make noise. I have heard them a lot.
These didn’t before the fuel pump failed. It’s a clicking sound loud enough to be heard inside the truck with the doors, windows, and hood, closed. I’ve verified it’s from the injectors.
Those TBI injectors are known for being noisy but by your description it sounds excessive even for them. First thought was excessive fuel pressure. You should check to make sure the regulator is doing its job. Simple test made difficult by the fuel line arrangement and lack of decent aftermarket guage set ups. I made my own for that reason.
Second thought was debris in the system. The old pump was weak. Did you change the filter at the same time as the pump? A strong pump could overcome a parially plugged filter and pass debris up the TB.
But remember, those were known to be noisy. You may have gotten used to them get gradually quieter as the pump degraded. Now you have a new pump with full power again…