Hello all, this is my first post in this forum even though I've been a member for about a year.
I am also a part of NYthirdgen.
I got the car in march 2012 and has been my daily driver ever since!
1992 Camaro RS 25th Anniversary Edition 305 5.0 TBI.


Problem I am having:

Recently, I noticed a tone coming from the rear of my car, sounds quite similar to the priming sound that the fuel pump makes as you turn the power on. I have not a clue if it has always made this sound and I simply have not noticed it or what, but i want to figure this out ASAP, before the winter comes lol.

Car drives fine as far as I can tell. Starts up fine. Occasionally upon startup I will have to let it warm up a bit before using it, even in the summer, because when I give it gas it will almost stall at times..RPMs go low.

Also, when it is idling at start-up, or after I am done driving and park it, I sometimes feel SLIGHT, FAINT thumps coming from the engine bay. Sometimes I will see the idle go from 750RPMS to 725, then back up too..I don't hear anything at all, only feel it occasionally...never really payed too much attention to it since it seemed to drive fine, no idea when that started, but now that i think about it, im starting to think it may be the pump.

What is new:

Fuel Filter
Spark Plugs
Plug Wires
Distributor Cap
Distributor Rotor
Battery
Alternator
02 Sensor
water pump

Question:

Am i supposed to be able to hear the fuel pump while the car is running?

Is there anything I can do to pinpoint if there is an issue with the pump, or if anything else is the culprit, or if there actually is anything wrong and I'm just making something out of nothing?

Thanks, guys! Really appreciate it!!

 

A good place to strart is test the fuel pressure. If the pump is making a low relatively steady whining noise its ok. Have you checked for vacuum leaks, this could be causing your RPM issue?

 

yeah, it is a relatively steady noise..if it starts to change as i accelerate, then i should be worried?

no, i have not checked for vacuum leaks..not really sure how i would go about checking that either.
I read somewhere to take some starter fluid or something and spray it around and see what area effects the engine? not sure how true that is, so i didn't want to go and do it without getting the story straight.

 

Define "whine" or "noise" from the rear, are you sure i'ts the fuel pump? does it only do it "at speed"? Does it sound like if you were blowing air across and empty bottle and making it higher pitched or wind through a cracked window? Or is it definitely more of an electircal pitch?

The former could possibly be the bearings going bad in the rear of the car, either the wheel bearings or ring and pinion bearings.

 

im pretty sure it is an electrical sound, it sounds very much like the sound the pump makes when it primes before you turn the ignition on. That priming stops as usual, so i know it isn't that the priming does not stop. I also started the car and put my ear up by the rear under the car and heard it.

Im pretty sure it is not the bearings or anything like that, because it happens when the car is not moving as well as moving.

 

Ok, just wanted to be sure you were able to tell the difference.

 

The sound the pump makes will only change depending on the vacuum even then the whine will only change a little.

Starting fluid works, spay a little around the manifold/throttle body gaskets and any rubber or plastic hoses going to or from the manifold and throttle body. have a rag handy for over spray incase you get some in the intake, you don't want to create any false positives. If there is a vacuum leak thee will be a noticable increase in rpm's. If you think you found a leak check it again to to be sure.

 

Since i was driving it around yesterday and today, i noticed that it seems to drive great..it's just when i stop at a light or i go to park that i notice it start to run a little rough. Also, the sound that I'm hearing is only noticeable while i am stopped, it is not loud enough that I can hear it while driving.

I am considering just changing all the vacuum lines regardless, just to be sure that they are fine..i mean they are pretty old by now, i doubt they have ever been replaced. Is there a thread or a guide to changing them all?

 

Yeah, no problem. I mean i AM still a newbie to a lot of this stuff, but i have done about 95% of the work that has had to get done. The only times I brought it to a shop were in the winter, as my garage is full of boxes so I have no other place to work other than my driveway XD. in the time ive had the car, I've come to gain a few skills, thankfully hearing things that would usually go unnoticed is one of them! lol

 

There probably is a thread around but really just take some of the old ones to the parts store to match the size.

 

alright, it is most definitely the fuel pump that is the problem. Sometimes when I am driving, the fuel gauge will give wrong reading. i parked the car and watched it for a little bit, and every time the gauge moves on its own, the car whines and shakes a little bit, so im sure the pump will eventually go..but is there any way to know just how much time i have? I'm supposed to go on a cruise all around upstate ny with the guys at NYthirdgen..should i risk it?

 

I wouldn't, but its entirely up to you. Just remember one thing, good old murphy will pop up when it's most inconvenient. You can always have a shop do it, most would be able to do it in less then a day. Drop it off while your at work, at the end of the day your set.

You can always do it your self, I changed my original assembly line pump out last month, it was a lot easier then it seemed. By the way one little tip, you will want the car set pretty high on the jack stands or you won't get the axel low enough for the filler neck to clear the body.

 

dammit, this sucks. god damn thirdgen.

 

Seems worse than it is, just pick up a walbro pump and get it done in under six hours, some people can do it faster but its still not that bad.

 

it isnt that bad, just get the car high enough and drop the rear. you dont even have to disconnect the break lines. also a second pair of hands to help position/secure the tank

 

Im not gonna have anyone available to help me with it till next sunday..so that means no tour for me =[

 

You don't have to have a second set of hands for the tank. If you use the return line to siphon the fuel out there will be less then two gallons left, it's not as heavy as you would think. Have one of the strap bolts in reach position the tank then you can hold it up with your right arm and start the bolt in the passenger side strap with your left. The filler neck will hold the other side while you get the other strap positioned.

The most time consuming part of the whole thing for me was outing the axel back in the car.