Maybe a Fuel problem

[SyberSaint]

Ok guys I sure could use some help here. I have had a noise problem with my car for a while now, and no one seems to be able to figure out what the problem is.

Here goes:

For a while now, while the car is under a light load, the car makes a clattering sound... It is a sound like when we were kids and we put playing cards in the spokes of our bikes. It is most noticable around 1800-2200 rpms, maybe a little higher, especially noticable in 2nd gear but in other gears and rpm ranges also... One thing that lends me to believe that there is a fuel problem is that when sitting for long periods of times, such as over night or when I am at work, it is hard starting... Once started it will start fine, but still has the clattering noise...

Could this be a fuel delivery problem (starvation) causing the clattering noise? The car has dual Cobra pumps installed, but one never knows about what can be going on...

Any help is appreciated
Thanks
Dale in San Antonio

 

[04YELLOWGT]

The cold start is probably in the tune. I had this problem to, if the car sat over night it would take 2-3 tries before shed finally start and then it would be fine untill the car cooled down again. I had the car retuned and never hafd a problem with it again.

As for the noise did you check your rear 02 sensors? I had a weird noise I couldn't figure out, it ended up being on of my 02 Sensors got loose and was rattaling alittle bit after I tightened it up the noise was gone.

 

[BobHyatt]

Ok guys I sure could use some help here. I have had a noise problem with my car for a while now, and no one seems to be able to figure out what the problem is.

Here goes:

For a while now, while the car is under a light load, the car makes a clattering sound... It is a sound like when we were kids and we put playing cards in the spokes of our bikes. It is most noticable around 1800-2200 rpms, maybe a little higher, especially noticable in 2nd gear but in other gears and rpm ranges also... One thing that lends me to believe that there is a fuel problem is that when sitting for long periods of times, such as over night or when I am at work, it is hard starting... Once started it will start fine, but still has the clattering noise...

Could this be a fuel delivery problem (starvation) causing the clattering noise? The car has dual Cobra pumps installed, but one never knows about what can be going on...

Any help is appreciated
Thanks
Dale in San Antonio

take a fuel pressure gauge and hook it up before you crank the thing first thing in the morning. Have someone turn the key on and watch the gauge. Does it jump right up to 40+ or is it slow? If it is slow, it is probably getting close to time for a new fuel pump as wear is letting the fuel drain back to the tank and it takes a couple of bursts of on-ignition to get fuel back up to the rails/injectors.

You can test this easily enough by just turning the key on, counting to 3, then turning it off without actually turning it all the way to "crank", stopping at "run". Do this 3-4 times and then try to crank. Did it fire right up? If so, fuel pump needs to go. Turning it to run runs the pump for a couple of seconds. Doing it multiple times will prime the system. Should not be needed after an overnight sit.

Pressure gauge will tell you more as probably when you turn the ignition off, pressure will quickly return to zero, when it should not normally do that...

 

[LucasMelo]

I have a Bullitt (with offroad-H and flows) that has the exact same problem.....
Just like you described.........
on low rpms, even on 2nd gear!!! gets worse on 4 and 5...

I don't think it's detonation......

This is my first V8 mustang and I bought it with 60K miles so I did not know if that was a problem or not since I never drove the car when new...?!
Car does not have starting problem but makes the clattering sound...

I just did a full tune-up and it did not change anything.
Plugs,fuel-filter,air-filter,oil, PCV, transmission fluid,
Ran seafoam over 5 times....

Engine can be Cold or Hot... does not matter...
Already used multiple tanks of 93oct gas with injector cleaners....
(I don't have a tune)

To me sounds like pump is not sending enough fuel when on low rpms...

Car sounds fine after 3K RPM.... no detonation either.....