Very rough idle

[Cabal]

Two days ago my 95 Talon Esi started a weird idle problem. It idles at 2,500 rpms, then after awhile it drops to 1,400 and back up to 2,500 (sometimes it just stays at 2,500-3,000 for a couple of minutes). It does this continuously as if i were reving the engine, also the engine light came on. I thought maybe bad gas, so i put in 93 octane, I also put in fuel injection cleaner, but it still does it. As far as the performace, everythings running great, the car shows no signs of problems unless I stop in traffic or at a light. What the hell can this be? please help, I don't know what to do!

 

[jthomp]

my best guess would be that's it's an idle system malfunction. To be correct "idle control system malfunction." It's the same thing i'm going through right now. Go get the CEL pulled and find out what's tripping the sensor. The ICS code is P0505. From what I've heard, it's not a cheap fix. I'm going to get it fixed this week, I'll let you know what happens...

 

[Cabal]

Thanx, please let me know what happened and what exactly was done. Im assuming I can still drive the car though, have you been driving yours?

 

[jthomp]

yeah, you can drive it. i'm driving mine with no other problems then just an annoying idle.

 

[Cabal]

So does anyone else have any ideas what might be wrong or is jthomp pretty much right in his diagnosis, cause im driving the car and dont plan on getting it fixed for a little while if i can get away with it.

 

[jthomp]

I'm taking the car in on Thursday morning. It should be done no later than Friday (hopefull). I'll let you know what happens with me....

 

[Cabal]

Thanx alot, I appreciate it!

 

[Keaka26]

check your BISS, it could have backed itself out to the point where it (idle) would go into a loop AKA idle surge. Also check to see if your TPS is within proper spec (should show 8-11% at idle on a datalogger)...

Next check your idle speed controller, it could possibly be bad.

 

[jthomp]

Alright, took the car in today to see what was wrong with it since it was idleing so rough. It came back with a bad idle stabilizer control system. Lucky me. The part - 289. The labor - 110 (55/hr in my area). All in all, not a cheap fix, but not too bad. Good thing I don't have pay for it. The dealer that I bought my car from is footing the bill...

 

[Keaka26]

idle speed controller....I think thats an expensive part from the dealer, good thing they covered it.

Its actually very easy to replace, but better they do it for you =)

 

[Cabal]

Thanks alot, you helped me out tremendously. The price wasnt that bad, but im broke right now. I wonder how hard it would be to install my self if I bought the part. I guess I'm just gonna live with it the way it is for a couple of months and save money to fix it.

Thanx to all, especially jthomp

 

[Keaka26]

replacing the ISC is very simple. All you do is pull your UICP, TB elbow, and TB. disconnect the sensors, and use an 8mm wrench to pull the 2 bolts from the ISC (attached to the TB) and replace with new one. Put back together.

 

[jthomp]

If money is an issue, and your handy with your hands and a set of tools, check out this website. http://www.crebotech.com/
They sell refubished ISC for about 90 bux. It has a 30 day warranty. Not to bad, I had mine replaced since the dealer that I bought my car from has a 30 day warranty on the car. Lucky me... Hope this helps...