How do you know if the fuel pump relay is bad or if its the fuel pump on a 1998 Chevy Silverado 1500 5oL?

Answer 1

Usually you when a fuel pump is good it will not be very loud when you turn the key to the on position (this primes the motor on your truck/car.) The same goes for when you turn the truck/car completely off!

If it is really loud it is getting restriction and it could either be your fuel filter or your fuel pump that is bad.

If you can't drive more than 20mph without the vehicle bogging out or sounding like it has a rev-limiter then the fuel filter or fuel pump is bad! It could be the wiring but that is RARELY the case.

Some people don't realize that they have to replace fuel filter and fuel pump every so often as it says in the vehicles manual for checkups after so many years or after so many miles.

I typically will go for a walbro fuel pump. I own a Nissan 240sx with a RB26 motor pushing 570whp on 22lbs of boost for over two years and the walbro hasn't failed me yet. And it is about $100.00 unless you get it off eBay for cheaper like I did ($50 shipped)

Change your fuel filter first in any case and if that doesn't solve your problem, bring it to a shop and have them test the pressure of the lines unless you have the tools and can do it yourself. Usually $20.00 at a local shop and they will test it to tell you if the fuel pump is bad or not.

If it is - replace it asap! You don't want to be stranded and have to pay for a tow with gas prices like they are now!