2001 ls 3.9 fluctuating idle @ start

[J. Sully]

So I own A 2001 ls with the 3.9 recently all of a sudden when I started it sounds almost as if it's backfiring any idol will fluctuate and it will almost die unless I put my foot on the gas Also I can smell fuel inside the cab really lightly and I wonder if the fuel pumps are leaking even know I've looked and I don't see anything at the top of the pumps underneath the back seat This is my 3rd LS so I'm very familiar with the cars but I am absolutely stumped on this one The sound when I try to start it sounds almost like a back fire but it's muffled. The car ran and drove perfectly up until just recently in all of a sudden this startedI don't have any Code showing as if yet but something is Obviously not Right. I've been reading these forms for a long time so I know that as a collective group there's a lot of information to be spread a lot of smart guys on here so hopefully somebody out there don't mind giving me some info or some tips I wrench on my own vehicles unless I have to open a transmission so getting me pointed in the right direction would help. Also I noticed that my fan all of a sudden is turning at a really slow speed and I opened up the reservoir and noticed the tranny fluid looks like a mud puddle it's no longer resembling any sort of tranny fluid so I'm wondering is the pump just not accepting it and possibly jam and up Making the fan not spin at the correct speed? Appreciate anything I can get from you guys.

 

[DaleGrib]

So I own A 2001 ls with the 3.9 recently all of a sudden when I started it sounds almost as if it's backfiring any idol will fluctuate and it will almost die unless I put my foot on the gas Also I can smell fuel inside the cab really lightly and I wonder if the fuel pumps are leaking even know I've looked and I don't see anything at the top of the pumps underneath the back seat This is my 3rd LS so I'm very familiar with the cars but I am absolutely stumped on this one The sound when I try to start it sounds almost like a back fire but it's muffled. The car ran and drove perfectly up until just recently in all of a sudden this startedI don't have any Code showing as if yet but something is Obviously not Right. I've been reading these forms for a long time so I know that as a collective group there's a lot of information to be spread a lot of smart guys on here so hopefully somebody out there don't mind giving me some info or some tips I wrench on my own vehicles unless I have to open a transmission so getting me pointed in the right direction would help. Also I noticed that my fan all of a sudden is turning at a really slow speed and I opened up the reservoir and noticed the tranny fluid looks like a mud puddle it's no longer resembling any sort of tranny fluid so I'm wondering is the pump just not accepting it and possibly jam and up Making the fan not spin at the correct speed? Appreciate anything I can get from you guys.

I would check out the fuel injectors and see if they are leaking. Also have you ever changed out the spark plugs and COP's? Did you ever check your fan reservoir before this happened? I ask because I once bought a LS and the previous owner had mixed coolant into that reservoir and it made it look similar to what you describe.