She's Dying.

[ThirtySix]

I love my car, and would be heartbroken to have to replace her, but im sitting on the line of whether it's time or not. 2001 grand prix GT 3.8L V6. Been having problems after problems and tired of taking it to expensive mechanics. Hopefully you guys can help.

Problem:
-Stalls in low RPM
-RPM fluctuates (100% of the time when i first turn it on, randomly after driving and randomly during park)
-might be unrelated, but the car sometimes violently kicks into gears. this has been happening for a while and only getting worse. Transmissions dying I'd assume.

Questions:
How can I fix the stalling problem? I will likely buy any needed parts from a scrapyard, as i know the transmission will die before new parts go bad again.
and
What can I do to prolong the life of my poor transmission?

Other info:
100+k miles, no check engine lights, fuel gauge sensor is broken, been using the car's gas usage sensor to judge when i need gas, just got a new catalytic converter, 2000 miles since oil change. problem occurs with cold and warm engine.

any help is Very much appreciated

 

[dsmuts]

Check for a vacuum leak. On the trans do a filter and fluid change with a bottle of lucas stop slip.

 

[GP Guy 07]

Were the plugs&wires changed or they originals and fuel filter is that also original? Clean throttle bodyor like mentioned vac tubes check for leaks.

 

[ThirtySix]

I have not maintained the car its entire lifespan. I will guess the plugs, wires and filter are stock, unless someone has a way to tell for sure.
And i am fairly new to this and will youtube how to check for vacuum leaks and get back to you tomorrow. I thank you guys profusely, the majority of my experiences with other forums asking a question and get completely ignored until the thread died. So 2 responses is a personal record. hah.
Any further ideas or suggestions will certainly not go unappreciated. possibly worst case scenarios?

 

[Timing]

Tune up
change fuel filter
1 bottle seafoam in 3/4-full tank
1/2 bottle seafoam in oil
1/2 bottom seafoam in vacline coming from brakebooster while car is running, when bottle is almost empty poor rest in fast to try to stall car. if it doesnt stall shutoff immediatly(you will need 2 people for this) wait 15-20 mins and start car let idle for 20-30 seconds and start reving it to clean all the **** out. Dont worry your car will smoke like crazy while pooring it in and when you start it the second time.
drive no more than 50-100 miles with seafoam in crank then...
change oil and filter
change plugs and wires
change pcv valve
change air filter
take throttlebody off and clean with carb cleaner
clean maf with maf cleaner
tranny filter and fluid change might help

Also forgot to mention if you do change your trans fluid and filter and it gets worse or stays you trans is most likly junk and a bottle of lucis anti slip might help prolong its life, but ive also heard people having tranny like problems due to carbed up throttle bodys and such

to check for vac leaks you can use carb clean around the vac lines and if the car revs higher there is your leak but the isnt fool proof and you dont always find one. Smoke test is the best and only for sure way to tell you have no leaks.You can also check your vac with a scan tool or torque app if you had it. typically my vac reads 19-22 idle

 

[Timing]

this you could all do yourself and would cost 100-150 depending if you do your tranny or not
if you need any help with anything dont be afraid to ask, most of us can easily walk you through

 

[BillBoost37]

The trans issue you mention sounds like it's seeing a long shift. Likely from a PCS/EPC soleniod (pressure control), the best way to help this w/o going deep into the transmission is to add a shift kit (trans go is suggested) and a bottle of lucas when you drop the pan and service the filter.

TripleEdgePerformance.com is one of the preferred vendors that sells the transgo kit.

On the other stuff. A tune up is definately in order, if you aren't comfortable doing the work... you know that one or two buddies that work on cars. Suggest that you buy the 30 pack and stop on over for an afternoon. It's not too bad on our cars.

 

[ThirtySix]

- - - SOLUTION - - -

I grabbed a car savvy friend of mine and we went to autozone. they plugged their computer into the dash, and nothing came up because my cig lighter fuse was blown, but the guy suggested a throttle position sensor solely from my description of the problem. But to my very pleasant surprise that was actually the solution! 45 for the TPS and another 10 spent on this little ratchet for a screw in a very awkward position.

But i do definitely need a tune up, my acceleration is not anywhere near as fast as it used to be. Thanks everyone for your help. I'll be sure to check up here next time my car's got a problem. and it will. I'm sure...

 

[Shiftingshaddow]

i would just add if you do think you are having transmission problems in the future (if this took care of the issue) take it to a transmission shop. you might need to check around a bit but there are two here where i live that will check it out for free and take it on a ride. certified transmission will scan it for free and they even helped me with free on advice telling me what to fix before i could even find out if i had a transmission related problem on my 99 gtp. on my 00 gtp they scanned it to verify the pcm was telling the car to shift into overdrive when i described my problem. no charge. they even did a look over on the rest of the car because i just bought it. a lot of places charge to scan but they did it free. i feel bad, actually, because i've never had them actually do any work but i would go there if i ever have to. their quotes were reasonable on rebuilds as well.