2000 GT stall at idle and when let off throttle

[burgundybullet]

Okay so I have a 2000 GT with roughly 156,000mi on it. It is currently -12F and I'm not sure if that is playing a part in this or not. It starts and generally idles fine to begin with. Then yesterday I was driving around and when I let off the gas to coast to a stop sign the engine stopped. I shifted into neutral and did a rolling start and put it back into gear after I stopped. Not that big of a deal but that wasn't the last time it did that. It seems to be fine and then after a couple minutes of driving instead of being at about 1000rpms when I'm sitting at a stop light it will be around 500 and then it will go between 500-800 and then kill itself. It also tends to do this when I let off the gas as well. It will start fine after it stalls. There is no miss as I am driving down the road or accelerating.

The car is pretty much stock. Just added a home made intake, replaced MAF sensor, and did an oil change from the 5w-30 I accidently put in last oil change back to the 10w-30. Not really sure what is going on and I kind of have to drive the car and with it being -12 I figure if I break down I may be in trouble pretty quick with how cold it is so I would like to try to get this solved as quickly as possible. Thanks in advance!

[Fivefingerdeathpunch]

Shotgun a crank sensor in it and maybe clean the IAC.

[burgundybullet]

Can I just use MAF cleaner for the IAC?

[burgundybullet]

Cleaned the IAC and no change. I never get above 45mph and then I have to drive through town and at most stop lights it wants to die. I will rev it in neutral to keep it going and then shift to drive when the light goes green. I did do 2 quick runs from 0-55 and then drove up and down mainstreet and its fine but if I don't do that its stall city at the stoplights. Anyone have other ideas? Still no engine light. Is it possible for there to be codes without the light?

[burgundybullet]

I was thinking about this some more as my car is still acting up after cleaning sensors. Could this be due to a clogged cat as it seems to be lagging a little bit when I try to slowly accelerate from 55mph. I go to give it a little bit of gas and it seems like it should be making a downshift from OD to 3rd but it won't and when it does it doesn't do it until it wants to shift to 2nd. If that makes sense. Like it will shift to 3rd and then go to 2nd to accelerate otherwise you have slow acceleration. I really doubt it is tranny related as it has been about a year since the rebuild by the tranny shop. Another thought that crossed my mind was maybe it was a throttle position sensor issue because it seems like more gas is getting in and its not telling the engine that. I don't really know exactly what the TPS does so if anyone has some more ideas feel free to post.

[burgundybullet]

Alright. Had the car out last night and noticed some things. When it would start acting up the headlights would dim and the heater would not blow very hard and then when I would rev it up the lights would get bright again and the heat would blow. I also installed a sub and amp not too long ago. Don't think that would be the issue but who knows. Feel free to chime in.

[burgundybullet]

Anybody?

[Scottydoggs]

i'd un hook the amp and see if the problem goes away.

or recheck all the connections. and the main grounds as well.

[burgundybullet]

Alright. And if my grounding of the amp was poor could that be a potential issue as well?

[Scottydoggs]

no, the main engine grounds, ( on the bell housing) the amp ground would only affect the amp.

[nos4blood70]

Check if all your battery leads are tight and maybe go get an electrical system test from Autozone or some place similar. Can't hurt.

[burgundybullet]

Okay. I think that I will probably end up taking it to a mechanic friend this weekend if I cant figure anything else out. We will see. Thanks for the advice so far!

[Scottydoggs]

check for vac leaks yet? the surging could be the cause of the lights and fan power dimming on you.

the fat vac line off the TB broke on mine, and it would surge at idle and wanted to stall. ( drove just fine) it was the line that went to the evap.

[burgundybullet]

I could check that too. Back when I had MAF issues I sprayed for vac leaks and was unable to find any. That was almost 2 months ago already. Wow where did the time go? lol. Guess it wouldn't hurt to check for that now.

[Nighthwk12]

The reason you are losing power is because your alternator shuts off under certain RPM. I would check the vacuum. Anytime I have had this problem it is a vac leak or MAF. Check your injector orings If you have any type of scanner you can see if the TPS is working.

[Scottydoggs]

when spraying the lines, move them some, pull on the lines some. mine would not show its self until i moved the lines a bit.

[l67ss]

check fuel rail pressure too

[burgundybullet]

Unhooked amp and it seems to be fine now. I don't understand why it didn't act up right away? Now I don't know what I have to do to be able to use the sub and amp... lol

[Scottydoggs]

rule one wins again, undo what you last did.

now you need a thread in the audio section lol

[burgundybullet]

I'm going to run it all week without the amp and sub and see if it does act up again. I just can't believe that was really it. lol. But at least it was free!!! haha