Idle problems: Need Suggestions...

[Blitzeclips]

Well, my car is doing wierd things again. First off, whenever I start the car and drive before it's warmed up, my RPMs like to stay around 2,000 for a couple seconds, then fall down to normal idle. This would occur at every stop I make until the temp gauge reads balance.

The other night I was going around 50MPH in 3rd, idle down to a stop. I shifted down to second around 30MPH and slid into neutral directly after. Normally the RPMs will calmy drop to 1000 but this time they dropped to 300-500, BARELY keeping my car alive from stalling. If I gave it gas, it would not help too much, just roughly idle. So the car would chug for a couple seconds then idle back up to 1500, and fall back down to a normal 1000. Directly afterwards, the drive will drive fine and great. Back to normal.

My oil pressure and vacuum read 25 and 20. Which is normal. My temps are looking good too.

I'm thinking this could be a TPS or MAP sensor issue. I will check everything for leaks and see what I come up with. I just need some help in finding what is causing this. I'm going to grab my buddy's TPS off his 420a and see what happens. Possible ECU failing on me? Could this be my coil pack going out on me? Wires? ANY ideas are appreciated. I'm hoping to fix this before things get worse. With my luck I'd break down in the middle of main street... AGAIN.

Thanks again guys.

 

[2GeNTSi]

Check the IAC (known by ISC as well). They happen to be a common problem that cause idle issues, mine went out a while ago as well. I bought a used one and it works better, every now and then I'll get a little bit of a fluctuation in the rpms (only on hot days though). But other than that, the car used to start around 500rpms, it starts normally around 900-1000 now that I've replaced it.

 

[Blitzeclips]

I did. Everything seems fine. I also noticed only 2/3 downpipe bolts were in. 1 of them completely fell out, and 1 out of the 2 in there was halfway popped out.

Thanks for the reply. I appreciate it. Somehow I help MANY others with their problems but rarely get replies to anything I need some opinions or help with. Once again I think I'll have to figure the shit out for myself.

I don't know why I post anymore. Apparently no one on the site has experienced issues or symptoms of an faulty ECU, sensor, or idle. So I have nothing to base my fixings with. Nor any idea where to start. Thanks again.

 

[VelocitàPaola]

WTF

Might I remind you about these threads...
http://www.dsmtuners.com/forums/showthread.php?t=239882
http://www.dsmtuners.com/forums/showthread.php?t=238447
http://www.dsmtuners.com/forums/showthread.php?t=225875

Sometimes you gotta give it more than a day before you receive a lot of replies...

 

[Blitzeclips]

WTF

Might I remind you about these threads...
http://www.dsmtuners.com/forums/showthread.php?t=239882
http://www.dsmtuners.com/forums/showthread.php?t=238447
http://www.dsmtuners.com/forums/showthread.php?t=225875

Sometimes you gotta give it more than a day before you receive a lot of replies...

Paul, exempt yourself from those comments. You of all have been most helpful. You know nothing was directed to you..

Does anyone know the voltage output of our alternators?

 

[VelocitàPaola]

The voltage should be about 14V at the alternator, providing the voltage regulator in the ECU is working properly. If it isn't, I believe the voltage can go as high as 18-20V (it varies with RPMs).

Now, I don't think your slow-falling-RPMs are anything to worry about, but if you have a spare TPS, you might as well slap it on and see if it makes a difference.

The near-stalling is what concerns me. It sounds very much like my own car, which I believe to have a dying ECU. There is a definite possibility that your symptoms might be caused by something else, so I'm hesistant to attribute your problems to the ECU. However, they are consistent with all the other dying-ECU stories I've heard. It's amazing how many of these 95 units are failing at the same time... maybe all the 96 ECUs will die next year.

 

[Blitzeclips]

Well, I'm glad we're on the same boat here, but then again, problems are something you should never be glad over.

The reason I'm thinking it may be the alternator derives from my problem today. I left my headlights on for nearly 4 hours and my car wouldn't start. Luckily, I grabbed my buddy's STI and used his battery to jump er...

She fired up alright, but once I checked some things over I noticed the DP bolts loose. So I shut the car off, assuming it would start again, and tightened these bolts down. When I went to start the car, it wouldn't kick over again. So I called another friend to stop by and jump it for me.

In the process, we ran over the idea of my alternator going out on me (he knows his car sh*t pretty well too). Especially with an Optima red top, the car should start right up after a good jump. Regardless if the car is turned off or not. This is the reason I'm thinking an alternator or grounding issue.

If the RPM drops when I'm coming to a stop, some wires may be moving a hair too much. Thus creating a short hesitation from loss of power, not HP, you know what I meen...

So I'll check my alternator voltage and MAP sensor again. I'll give Thom (Malenko, moderator @2gnt) a call and steal his TPS. Then we'll see what happens.

PAUL- What steps have you taken to check the problem? Any more ideas?

 

[shiftdrift06]

Keydance FTW!

Sorry thats my suggestion for alot problems along this line.
It worked for me anyways..

http://www.2gnt.com/nuke/modules.php?name=Sections&op=viewarticle&artid=8

 

[VelocitàPaola]

You can try checking the magnet in the CMPS...

I don't really know what to check other than that. My car would just stall and die at odd, random times, and would buck during acceleration... again, at odd, random times. I don't drive my car often enough to be that concerned with it, plus I have MSnS to look forward to.

 

[Blitzeclips]

. I love that response Paul. You don't drive it enough to care. I wish I was the same way. But that does sound like my previous problem. You know what it was?

Either:
-Bad gas (let ISOLEET sit in the tank overnight)
-BAD plugs
- gunked up MAP sensor

These are the only 3 things I did to fix the problem, and it worked. So, I figured it was 1, 2, or all 3 that caused the problem. Took me 20 minutes and everything was good.

I think it's my alternator at this point. The car WILL NOT start but the lights come on an dim ever so slightly. This leads me to believe my alternator is not re-charging the battery, therefore I'd be using ALL the power directly from the battery. I'm not trying to drian my $130 battery for 1 trip to work.

So, tomorrow I'm going to check the voltage or wires from battery--->alternator (hopefully loose), if it's under spec, I'll put a new alternator in on monday. They're what, $100 or so?

I HOPE thats the issue...

But Paul, youshouldn't look forward to MSnS just yet. If you're getting a bucking and random stalling NOW, at 8 psi, just imagine what would happen under boost of 12+. ESPECIALLY if it's something damaging your motor. You should catch that early before you upgrade, incase it's leading up to complete motor failure for some dumb, odd, 2gnt reason..

 

[VelocitàPaola]

You know what it was?

Either:
-Bad gas (let ISOLEET sit in the tank overnight)
-BAD plugs
- gunked up MAP sensor

These are the only 3 things I did to fix the problem, and it worked. So, I figured it was 1, 2, or all 3 that caused the problem. Took me 20 minutes and everything was good.

Nah, everything that could have been replaced was replaced. And when I'm home, I drive my car so much that the gas tank's turn over rate is pretty high. I'm sure it's the ECU.

I think it's my alternator at this point... They're what, $100 or so?

About that... maybe closer to $150. Don't forget the core charge either!

You're in for a hell of an install experience. The alternator is in one of the most ridiculously designed areas ever. Just remember that you need to jack the engine up (w/ pass. side mount off) and partially remove the whole alt. bracket. A friend of mine and I did it for the first time together in about 4-5 hours.

But Paul, youshouldn't look forward to MSnS just yet. If you're getting a bucking and random stalling NOW, at 8 psi, just imagine what would happen under boost of 12+. ESPECIALLY if it's something damaging your motor. You should catch that early before you upgrade, incase it's leading up to complete motor failure for some dumb, odd, 2gnt reason..

I think you're missing the point... I've pretty much narrowed down the possibilities to just the ECU. MSnS will replace the ECU, and thus, my problems are over.

 

[Blitzeclips]

You're in for a hell of install experience. The alternator is in one of the most ridiculously designed areas ever. Just remember that you need to jack the engine up (w/ pass. side mount off) and partially remove the whole alt. bracket. A friend of mine and I did it for the first time together in about 4-5 hours.

Grreeattt. Well, I've already found a couple areas HORRIBLY DESIGNED for our cars. I'm guessing this is another on the list.
I honestly hope theres just a loose connection on it.
I'll figure it out somehow. Thanks again for the input Paul.

 

[Talon ESI-T]

Your Alternator is fine. Anyone who claims the battery will charge in a 5-10 mins of idling does not know automechanics very well. General rule of thumb is that, if your going to let the car just idle, let it run for 30mins. If your going to drive the car then drive it for 15mins. After 8 years as a tech, I have come to learn this is true.

Your TPS is a likely culprit. You need to get it on a datlogger of a automotive scanner and watch the TPS value. If the TPS value changes when your RPM's begin to change then you have a bad TPS. I have caught several TPS related issues like this on Chrysler based cars and found NO CODES. The ECU only trips codes when the values of multiple sensors are not seeing eye to eye or when the sensor is out of range. The ECU is not much smarter than a very meticulous person, just much faster.

Terry

 

[doggo]

I did. Everything seems fine. I also noticed only 2/3 downpipe bolts were in. 1 of them completely fell out, and 1 out of the 2 in there was halfway popped out.

Thanks for the reply. I appreciate it. Somehow I help MANY others with their problems but rarely get replies to anything I need some opinions or help with. Once again I think I'll have to figure the shit out for myself.

I don't know why I post anymore. Apparently no one on the site has experienced issues or symptoms of an faulty ECU, sensor, or idle. So I have nothing to base my fixings with. Nor any idea where to start. Thanks again.

You say you checked the ISC. How? Keep in mind it's possible to pass ISC tests (esp the coil resistance test) and still have a bad ISC.

 

[Blitzeclips]

Well, I haven't been able to work on or check the car for the past couple days because I've been busy with school, work, etc...

So last night I let the car idle for about 15-20 minutes(after jumping via another car) and I checked the battery voltage. Read 13.8V. I didn't have time to check the alternator because it was 11:00 at night and pitch black out. So, after letting it idle and shutting it off, it started right up without jumper cables.

When I went to start the car today, it wouldn't kick over. No lights whatsoever, radio or anything doesn't work. It's just dead.

So I don't know what the problem is. I'll check my alternator tonight but I'm ready to take it to the shop for the install. I'm about fed up with this car. There's no way I;m spending 5-6 hours for the alternator. I'm just tired of being underneathe the damn thing all the time.It's either something today, tomorrow, or a couple weeks from now. Reliability has dropped dramatically, its just being a HUGE PITA. I'm tired of getting rides everywhere when I've put alot of money to get this thing running, and running right at that.
Out of curiousity, Paul, Terry, or whoever has replaced these themselves, how many hours would it take if you were using a lift and had better access to the unit?

 

[Talon ESI-T]

If it started one night on its own and it wouldnt start the next day, your problem is either a parasitic draw or a bad battery. I think you should take it to a shop, this is beyond your experience.

As far as how long it takes me to change an alternator. 2 hours tops but I was a machanic for years and have close to 30k in tools. you can compare yourself to me. without some of the tricks and specialty tools i have it would take longer. I would say for the average person with minimal tools 3-4 hours is realistic on he first try.

Terry

 

[VelocitàPaola]

I think that if you know what you're doing, and you're determined to get it done quickly, you can replace the alternator in 2-3 hours. A lift probably wouldn't help so much, because either way, the alternator needs to come out the top. There is no way to get it out the bottom unless you shift the engine and remove the axle.

Here's how I would do it if I were you...
*Remove the two electrical connections to the alternator.
*Place jack under oilpan to help support some of the engine's weight.
*Remove the center bolt in the passenger's side motor mount.
*Jack the engine up as high as it will go.
*Loosen the tensioner and push the belt aside (you won't be able to take it off completely unless you remove the other acc. belt too).
*Unbolt the alternator from the brackets and let it rest on the axle.
*Loosen the appropriate bolts on the upper bracket/tensioner to get it to swing out of the way.
*The alternator should now be free to come out.
*Repeat the above steps in reverse.

I think I might have factored in the fact that we still needed to buy a new alternator into that first time estimate... Also, there wasn't anyone there to tell us how to do it step by step.

If your battery actually charged to ~14V after running the car, then I would say the alternator is doing its job just fine, though. It sounds like your battery is draining because of something else. I'd blame it on the battery itself if you hadn't already replaced it. Take a look around for grounded power wires that might be causing it to lose its charge so quickly.

 

[TalonESIT]

Well, I haven't been able to work on or check the car for the past couple days because I've been busy with school, work, etc...

So last night I let the car idle for about 15-20 minutes(after jumping via another car) and I checked the battery voltage. Read 13.8V. I didn't have time to check the alternator because it was 11:00 at night and pitch black out. So, after letting it idle and shutting it off, it started right up without jumper cables.

When I went to start the car today, it wouldn't kick over. No lights whatsoever, radio or anything doesn't work. It's just dead.

So I don't know what the problem is. I'll check my alternator tonight but I'm ready to take it to the shop for the install. I'm about fed up with this car. There's no way I;m spending 5-6 hours for the alternator. I'm just tired of being underneathe the damn thing all the time.It's either something today, tomorrow, or a couple weeks from now. Reliability has dropped dramatically, its just being a HUGE PITA. I'm tired of getting rides everywhere when I've put alot of money to get this thing running, and running right at that.
Out of curiousity, Paul, Terry, or whoever has replaced these themselves, how many hours would it take if you were using a lift and had better access to the unit?

It has been a while since I changed my alternator, but 5-6 hours sounds like a bit too long. It is not that bad when you jack up the car and secure with jackstands. If you dont want to deal with it and want to bring it to a shop it definately will not be a 5-6 hour labor fee, not even 3.

I am just curious about your battery and your terminal connections, is there any corrosion on the terminals? Are they clamped down to the battery securely? As stupid as that sounds I had that issue with my car quite often. My battery cable would lift off the battery because of the engine vibration and just driving, so when I would go and start the car randomly it would not start.

Also, you aren't running an safc are you?

OH yeah! Also check your o2 sensor, I had the same bogging problem and starting issues until I changed my o2 sensor.

 

[Blitzeclips]

Well, the hearing 3 hours of labor is all it may take, is definately re-assuring. I don't want a $400 bill for this thing. Because if that were the case, I'd suck it up and install the thing myself. As much as I don't want to...

I have checked both battery terminals almost a dozen times. I even re-tightened them about 1/8 of a turn. So they're VERY secure at this point. My uncle is my mechanic, well, whenever I can't figure something out I turn to him and his shop. I;m going to pull the battery out and take it to him tonight and charge the battery. Then we'll test it to see if it's up to spec.. But it seems like the battery is the only thing allowing the car to start. Within the time we let it idle after jumping it, the alternator should have charged it enough to start again. Thus, the car actually duiling and starting because the battery DOES have power, but is being drained because the alternator is not continuing supply of it. Thus the reason the car will start and idle, but cannot do the same without an alternate source of power(jumping). I dont know..
Nope. No SAFC. I should have one but I was ripped off by a member of dsmtader.com for $200. I was going to steal my buddies if needed for the install, but I don't see a reason for it anymore. MSnS will replace all that next year.

I haven't checked the o2 sensor though. I know I replaced my downstream o2 for the install, but not the primary on my downpipe. What voltage should that read? 12V I'm assuming?

Also, I was thinking it is grounding out also. It seems like power is being drawn from the car ALL THE TIME. Doesn't make sense. The thing is, this could take HOURS of hours to find. I have no idea where to start with it. If I had electrical skills, (which I don't AT ALL ) I might notice something out of the norm. Where you you guys begin to look for looose connection or grounding out?

 

[totaleclipse_05]

Terry is right, sounds like a parasitic draw or a bad battery.

 

[Blitzeclips]

Terry is right, sounds like a parasitic draw or a bad battery.

I HOPE it's the battery. Optima red tops come with a 2 year warranty.

 

[Talon ESI-T]

Paul, i prefer to remove the Alternator from the bottom and I leave the axle in. You have to remove the lower bracket and the plastic shield and it will fit throught the opening at just the right angle.

This is with the car on jackstands as well. Sometimes removing the 3 nuts on the shock tower allow you to lower the axle just a hair more but i have gotten it out without it.

I dont recall removing the axle last time.


Terry

 

[VelocitàPaola]

Paul, i prefer to remove the Alternator from the bottom and I leave the axle in. You have to remove the lower bracket and the plastic shield and it will fit throught the opening at just the right angle.

This is with the car on jackstands as well. Sometimes removing the 3 nuts on the shock tower allow you to lower the axle just a hair more but i have gotten it out without it.

I dont recall removing the axle last time.


Terry

Really? When I was down there, I tried every which way to try and get that thing out from the bottom. I remember thinking that the engineers at Mitsubishi/Chrysler probably laugh weird times because they get random thoughts of someone trying to remove this alternator... oh, and that there was no possible way for it to come out the bottom.

I took the plastic shield (we're talking about that little black thing around the +Vout post, right?), and I pulled the lower bracket too... maybe it just wasn't at "the right angle." Oh well, I'll try to figure it out if my new one every fails on me.

Coming out that top wasn't that bad, though, you just have to know what you're in for before you start.

 

[TalonESIT]

Really? When I was down there, I tried every which way to try and get that thing out from the bottom. I remember thinking that the engineers at Mitsubishi/Chrysler probably laugh weird times because they get random thoughts of someone trying to remove this alternator... oh, and that there was no possible way for it to come out the bottom.

I took the plastic shield (we're talking about that little black thing around the +Vout post, right?), and I pulled the lower bracket too... maybe it just wasn't at "the right angle." Oh well, I'll try to figure it out if my new one every fails on me.

Coming out that top wasn't that bad, though, you just have to know what you're in for before you start.

, I was trying everything too! It physically would not come down from the bottom! I thought I tried every angle possible; it was like trying to fit a square block through a triangular hole.(never was good at that stuff as a child =P )

 

[Blitzeclips]

Well good news guys, I took the car over to my uncle's and we charged the battery. It was D-E-A-D. I meen, NOTHING left in er'...

THen we pulled out a system (expensive program/unit) that checks the current throughout your starting/charging system. Everything checked out just fine.

So at this point the RPM's dropping is still an issue. TPS is a likely culprit but it COULD be the ECU... Thing is, it happens randomly, not ALL the time.

I'll check everything for a 3rd time on Sunday.

P.S- Does ANYONE know what belt I can use for my Power steering?? I removed the AC charger and belt but I want my P/S back. I was thinking a 35 tooth neon belt?