power issues

[boris_37]

okay well, i recently got a car stereo installed (1000w amp, 2 750w subs) at bestbuy. I get home and start driving around and notice my RPM are flying up and down. My car is now stalling when my foot is no longer on the gas, and the RPM are not staying at a constant.

My car is '90 and my father thinks it is either a dead short somewhere from the AHEM people who installed it, or perhaps we fried something on the computer module when we wired the subs. he also thought that the stereo system might be draining too much power from battery but we unhooked where the fuse connects and were still having the same problem.

My friend gave the idea the battery is bad, and is why we might be having this problems?


Anyone have any solutions and/or ways to fix it? thx

[Manny_boy]

Did they disconnect your battery when they installed your system? It sounds like you need do an idle relearn procedure. Anytime the battery is disconnected for an extended period of time, your computer loses the idle speed settings, and will cause the symptoms you describe.

There are a few methods floating around for idle relearn, but this is the one used by GM techs.

Reset ECM by pulling ECM fuse for a few seconds.


With A/C turned off, start car and immediately put it in Drive
with your foot on the brake. If the car does not start initially,
keep trying WITHOUT putting your foot on the accelerator.


Let the car idle in gear for at least 5 and no more than 7 minutes.


Shut off the car for 10 seconds.


Start engine, place in drive and let idle for 5 minutes.


Shut off engine.


Idle is learned.

[boris_37]

k that sounds good. i will try it. any other ideas? i am pretty sure they did unhook it, and the timing might be off. but i want to explore every option before i start fiddling with my car

[Manny_boy]

How old is your battery? After a few years, batteries lose their ability to hold a sufficient charge. That can cause a host of problems, like alternator death (overworked from trying to charge a dying battery)

[boris_37]

Originally Posted by Manny_boy

How old is your battery? After a few years, batteries lose their ability to hold a sufficient charge. That can cause a host of problems, like alternator death (overworked from trying to charge a dying battery)

well not sure. i bought the car last year... we weren't having these problems before i got the subs installed. i thought it might have been the battery but my car starts just fine, its just when i am idling in drive(eg slowing from 50-0 at a stop sign) the car stalls. I also thought it might be the alternator as well. but when we disconnected the system and kept running the car it was having the same problem...

[Manny_boy]

That last problem sounds like your TCC (torque converter clutch) - it is supposed to disengage when you are decellerating- when it doesn't and you come to a stop, if the torque converter is still engaged the car will stall. You may want to see a tranny shop about that one.

[boris_37]

Originally Posted by Manny_boy

That last problem sounds like your TCC (torque converter clutch) - it is supposed to disengage when you are decellerating- when it doesn't and you come to a stop, if the torque converter is still engaged the car will stall. You may want to see a tranny shop about that one.

but would that account for the fluctuations while i am sitting still eg (in drive, but stepping on the brake so at 0mph) and the rpm keeps going up and down....

[Manny_boy]

nope - the rpm fluctuation definately sounds like the idle speed control motor is hunting for idle... the idle relearn should take care of that.

[boris_37]

Originally Posted by Manny_boy

nope - the rpm fluctuation definately sounds like the idle speed control motor is hunting for idle... the idle relearn should take care of that.

k if my father is up to it, we will try it tonight, if it works is it wrong to say i love you? haha

[NeonKnight]

Originally Posted by boris_37

k if my father is up to it, we will try it tonight, if it works is it wrong to say i love you? haha

i know for a fact that its just your Idle needing to be reset, when i installed my stereo myself i had to do the same thing.

Just do what jeffco said uptop and ull be in good shape. but dont let anyone tell you its anything else. the RPM flujx is 100% idle relearn nothing more.

Happens since they dissconnect ur battery while doing the stereo stuff so they dont fry the electronics and all.

Good luck with that. Be careful with the truck. i near rattled mine off with my 2 12's

[boris_37]

Originally Posted by NeonKnight

i know for a fact that its just your Idle needing to be reset, when i installed my stereo myself i had to do the same thing.

Just do what jeffco said uptop and ull be in good shape. but dont let anyone tell you its anything else. the RPM flujx is 100% idle relearn nothing more.

Happens since they dissconnect ur battery while doing the stereo stuff so they dont fry the electronics and all.

Good luck with that. Be careful with the truck. i near rattled mine off with my 2 12's

yeah my subs got rewired from my friend. on high my whole car shakes. literally sounds like its gonna fall apart... haha