Yes, a malfunctioning Fuel Pump can affect idle speed quite severely by not providing the constant fuel flow needed to operate an engine smoothly. A lean fuel mixture, or one that fails to deliver sufficient pressure may cause an engine stall during idling. This is what causes the rough idling as your engine constantly tries to keep itself at an idle on too much fuel and not enough air. Research has revealed that even a small 10-percent drop in fuel pressure darts can have an noticeable effect on idle quality, with RPM fluctuations and occasional stalling.
Modern vehicles are designed to inject fuel at precise pressure levels, from 40-60 PSI (pounds per square inch), which is conducive to proper operation of the CVT. Anything less than these numbers, and the fuel injectors can remain open too long for idle due to a low pressure (and spring setting) from their mechanical regulators. This inconsistency often causes the idle speed to vary greatly and for RPMs too low or too high.
For example, when the fuel filters get clogged and/or if your vehicle has a failing or bad fuel pressure regulators that requires more work for the pump to pressurize in consequence this make it inefficient and reduce its output pressure. This loss of fuel flow can be as much as 30 percent, notes automotive experts, which not only affects idle speed but also may cause engine stumbling during acceleration. Change your filter regularly, preferably every 15-30 thousand miles to curb these sorts of issues and keep that fuel pump healthy throughout its life.
This could lead to possible long-term damages of the idle speed behaviour in response to fuel pump-related problems. Long term low fuel pressure can cause a build up of carbon in the engine as incomplete combustion causes deposits to form on important parts. This in turn causes the engine to wear faster, decreasing gas mileage and potentially requiring repairs. Almost all the mechanics will say that fixing a fuel pump earlier can reduce repair bill which might be hundreds of dollars.
If you are thinking how to maintain your Fuel Pump To Stop Idle Issues And For Best Performance, must read the role of consistent pressure and proper maintenance support.