Alright, someone has to know whats going on with my Idle problems.

[2000GTX]

Okay guys, I've had idle issues since I bought this car, and I've done everything from MAF to AIC to TPS to who knows what else.

The problem I'm having now is that once the car gets warmed up, when I come to a stop, it tries to stall, then the AIC kicks in shoots it to regular idle, then a second later is tries to stall again.

Keep in mind, when I get on the gas it has no problem accelerating and feels completely normal, but at speed, once I'm off the gas, the car lurches forward while decelerating. My theory is that the fuel flow is irregular. Does that sound about right? I've got a new fuel filter to throw in, so that's my next shot in the dark. Any input is appreciated.


Also, if anyone has info about how the E-Brake works and stuff that would be cool too, because my E-brake light just started staying on when the brake is completely off, so I'm assuming its sticking or something like that.

Anyways, Thanks for reading, and if you have any input at all, I'd really appreciate it.

 

[steve]

Have you replaced the caps in the ECU?

Your brake light is on because your brake fluid is low.

 

[2000GTX]

I haven't checked the caps on the ECU, but the ECU has a stamp thing on it that says it was inspected by some dude in 2007, I dunno if that means anything.

Brake fluid.

Low. Brake. Fluid.

F my life, I'm an idiot. Well hopefully I can sort that out tomorrow then.

What about a new PCV valve? Is that something I should look into?

 

[EHmotorsports]

Do all normal maintenance if it hasn't been done yet. Get the basics out of the way. But it sounds like you are in Limp mode due to the idle searging. That means the computer is trying to adjust the timing to make the car idle. Instead of the IAC doing the adjustment. So coolant sending unit, O2, bad caps in the ecu, can all cause this issue. What fault codes do you have?

 

[2000GTX]

Unfortunately I don't have anything to pull codes with.

CEL isn't on, but that clearly doesn't mean much.

 

[EHmotorsports]

You jumper the pins and watch the light flash in the dash. Google reading codes 91 galant

 

[2000GTX]

Oh man alright. Let me read. Thats some cool information that I didn't know before.

 

[EHmotorsports]

Ya a Hanes manual should have that info in it also. 13-15 at a parts store.

 

[2000GTX]

All the stuff I'm finding needs an analog voltmeter.

Do you have a specific link?

I found the code translation stuff.

 

[2000GTX]

Or could I just use an LED rather than a meter to watch the pulses?

That would probably work.

 

[cheekychimp]

Does this only happen when coming to a stop at a junction? Do you have issues with stalling at low speeds, i.e. when parking in car parks etc?

 

[2000GTX]

It doesn't try and stall, but it does still fluctuate. Like, for instance if I hold the gas at ~1200 rpm, it will still dip down to about 800 then come back up.

 

[GSX_TC]

Y'all are forgetting about one very important cause of idle issues, the throttle body. My VR4 had this same problem and when I sent my throttle body to Steve Monroe over at throttlebodies.com he rebuilt it with all new seals and got it brand new, when I put it back in, all my idle issues went away. Just a suggestion in case you haven't done this step yet.

 

[cheekychimp]

Mike makes a valid point and it is never a bad idea to replace, clean or rebuild parts in an attempt to get everything working perfectly. In my limited experience however, idle problems rarely come down to a single issue.

This is an old thread of mine that helped me resolve a number of issues web page

Is your throttle body grounded properly? This sounds like it might be the IPS not getting the signal that your throttle is closed?

 

[2000GTX]

Well, I haven't had my TB rebuilt by a professional, per se, but I have taken it off a few times and cleaned it. I actually bought another TB from a guy on this site and the condition of my idle was even worse than before, so I threw my old one back on. Should I send that extra one out to whoever did yours? How much does something like that cost? I think I've read someplace that someone will do it for like 75 bucks but I don't remember.

And I couldn't tell you either way if it's grounded properly. I don't think I could even tell you what an IPS is to be honest. I'm not really familiar with a the things I haven't dealt with (or tried to deal with) yet.

So any info either of you guys have would be useful, I'll read through that old thread for sure and see if I can rustle up any info.

 

[Racah15]

IPS=IAC, or Idle position sensor

 

[2000GTX]

Also, does it make any difference that this gets worse once the car warms up?

Like, if the car is cold, it idles fine, but once the car has been driven 5+ miles-ish, that's when all this starts.

 

[2000GTX]

Quoting Racah15:
IPS=IAC, or Idle position sensor



Righteous. Well I mean, I have the new model black color IAC, and it's just hooked up via the regular old wire harness. So I don't know why it wouldn't know the car is idling. I'm assuming it would know via that little button on that switch on the top of the TB, right? Maybe that switch/connection is bad?

 

[2000GTX]

Okay, so my ideas for tomorrow are as follows:

Replace Fuel Filter
Replace O2 sensor
Take off the EGR and clean that beast out
All the while, searching for a vacuum leak

So we shall see if any of that nonsense makes a difference.

 

[cheekychimp]

Quoting Racah15:
IPS=IAC, or Idle position sensor



Quoting 2000GTX:
Righteous. Well I mean, I have the new model black color IAC, and it's just hooked up via the regular old wire harness. So I don't know why it wouldn't know the car is idling. I'm assuming it would know via that little button on that switch on the top of the TB, right? Maybe that switch/connection is bad?



I hear a lot of different terminology on here and I'm never sure what is correct but I refer to the two different items as:

ICS = Idle Control Sensor (this is the black or brown 'motor' that physically moves to regulate air flow past the throttle plate and therefore idle rpms)
IPS = Idle Position Switch (the little 'button' that you referred to which tells the ECU that the throttle plate is closed and hence to start idle control)

If that button or sensor isn't grounded, it doesn't work. The ECU then gets no indication that the throttle plate is closed and doesn't know it is supposed to be looking after the idle. Without ECU intervention the idle motor won't work and hence your rpms drop drastically as soon as you come to a stop. Again I can't guarantee that this is your issue but at least you need to know what you are looking for.