Still has odd idle issues...

[EuroFanatic]

I used the trouble shooting tips here: Terry's Talon Troubleshooting Tips #3 - Fast Idle (aka. Idle Surge) for 2 days now. My idle issue is not quite like what is described... I have fixed just about everything I can on it and still not sure what is going on.

When first starting up, the car wants to idle about 3-400RPM and runs like absolute garbage, idle bounces up and down and will sometimes shut off, feels like a massive misfire but there are NO codes and the scan tool does not log anything abnormal when running, so I hop out and adjust the BISS screw to bring it up to 750 which evens the idle out some.

I go for a short drive just to bring it up to temp, now it will not do below 2500-3k rpm, even in 1st gear with no clutch being depressed the car pulls itself along fine like I am gibing it throttle. So I go back home and screw the BISS back in all the way, (put a new Oring on it already) and the idle drops to about 1500, so I use the throttle body screw to drop it to the 750 mark. Now there is a very small miss but idles relatively smooth and sounds like an engine should. Done right? Wrong.

Let the car cool down, decide to go for another drive, let it start up cold....and runs like $hit again. Go back to step 1, adjust everything for an ok cold idle and fix it when it stays at 3k rpm.

I used an entire can of brake clean when the engine is cold, and another can with the engine hot. Did not find a leak anywhere. Any ideas???

Edit: oh also ALL vac lines are new and MAP sensor is new.

 

[92AWDHX40]

Is this a new idle thread?

 

[EuroFanatic]

Nobody responded to my last one . Plus the situation has changed.

 

[CrawlinZX14]

Ok, so let me get this right. First you started another new thread about this issue?

Next, Your idle cold is 3-400RPM which means your biss is out of line since you should be idling near 7-800rpm. Next, you have a new MAP sensor? Last time I checked these cars come with a MAF sensor which is located before the turbo with your air filter attached to it. A map sensor is a Manifold Absolute Pressure sensor, and is ran together with an AIT (air intake temp sensor) to turn a car into speed density. So what exactly do you have?

To me a really all over the place idle would lead me to a MAF being bad or unplugged. fast idle valve could be an issue of yours as well. Visual Frequently Answered Questions - Home Page Look here and take your time. Its really not that difficult to figure out if your methodical about it. I have an issue with mine on cold starts too, but I already know what I need to do to fix it.

 

[92AWDHX40]

I learned sometimes it takes time to get to a thread or have a answer to a question, and with idle there are so many vairables that will affect it. I seen others start threads over again, having similar issues have been mered to one thread , such as idle, bse, smoking, overheating and such. Maybe someone will chime in.

 

[EuroFanatic]

Yes I have a new MAP sensor, the one on top of the intake manifold. I had an issue with not getting any codes so I fixed that, my check engine light finally worked and it coded the Manifold Absolute Pressure sensor. At the time the car ran horrible at all times and ran soo rich a spark could have blown up the garage. The new MAP sensor cleared up the once warm idle and at all times the car now has the exhaust smell of a normal running vehicle.

Because the car was warm it was running properly I turned it off thinking I had fixed the issue. A few hours later I hopped in it to have it idle about 200rpm and feel a massive misfire feeling (no CEL). back out the BISS screw and even it out to about 750rpm (I am using a MATCO portable scanner to see digital RPMs). Once running even at 750rpm there is a slight miss, not enough for me to want to look at, at the time so I took it for a spin down the block. On the way back the idle would not go under 3k even when putting it in low gears only going like 5mph the car will accelerate up to speed. So I bring it back home, while running, pop the hood and screw the BISS back in all the way, drops the idle in half to around 1200-1500rpm. I then use the throttle adjustment screw and back it out until I hit the 750 mark again. While hot, I can back it down to test about 400rpm and still have it run smooth without dieing, but I set it to stay at 750rpm. Let it sit a while, hop back in and it does the same thing. I feel like I am running out of options for what in the world can be wrong.

Also the scanner shows the current TB position in a % form, and will change by what I set the screw to, so I assume that sensor is doing its job properly.

 

[okm12346]

The lower portion of your TB has the FIAV or the fast idle air valve. It's spring loaded and it has wax in it - it works like a thermostat, the spring opens and closes a valve which lets more or less air in the intake manifold bypassing the TB. When its cold it lets more air in, when the engine warms up, the warm coolant flows thru there and heats up the wax and the valve closes. Now this part get dirty - there are many reasons for that (faulty turbo will push oil thru the IC piping in the TB, faulty PCV valve will do the same, running straight water as coolant will build residue on parts, incorrect timing can cause backfire back in the intake manifold). So the FIAV will get stuck open and let certain amount of air causing your issue.

I had this problem for a long time and i got tired of it, so i installed a FIAV block off plate. It cost about 10-15 bucks off ebay. I havent had any idle issues since then. Many people don't like it, because on a cold start up you have to hold your foot on the gas pedal until the engine find itself and idles alone. It takes minute or two to do that. I'm used to it and it doesnt even bother me no more.

It's either this or buying a new bottom portion of the TB or trying to take it apart and cleaning it

 

[EuroFanatic]

I have actually been reading about this for a little while tonight...

Can I attach a multimeter to it like the ISC to get an Ohm reading, or any other way to diagnose it? I would assume it would have different readings for hot and cold.

Also, the ISC appears to have 6 terminals on it, but the descriptions for testing it talks about 4 terminals...is there an image to use for which terminals to check?

I was looking around, and I see information related to a Talon doing a similar problem...could the Coolant temp sensor cause idle issues when cold, and once warm it becomes fine again?

 

[CrawlinZX14]

get us a picture of your engine bay please. Cause I would love to know why you have a MAP sensor on your car. And if you indeed do, what is reading it? What ECU does the car have in it? There are a million and one things to know. I dont see why you simply could not just replace the throttle body with a larger aftermarket one with the FIAV removed and just be done with it. Then if you have a DSMlink or some other aftermarket ECU then you should be able to turn the code it will throw off.

Since last time I checked, the 2g DSM's have MAF systems and thus a MAP sensor is likely not stock.

 

[okm12346]

By Map sensor he means the manifold absolute pressure sensor which is located on top of the intake manifold and its function is to check if the egr is functioning.

 

[mchustle]

get us a picture of your engine bay please. Cause I would love to know why you have a MAP sensor on your car. And if you indeed do, what is reading it? What ECU does the car have in it? There are a million and one things to know. I dont see why you simply could not just replace the throttle body with a larger aftermarket one with the FIAV removed and just be done with it. Then if you have a DSMlink or some other aftermarket ECU then you should be able to turn the code it will throw off.

Since last time I checked, the 2g DSM's have MAF systems and thus a MAP sensor is likely not stock.

The op is correct he has a map sensor stock along with every other 2g and ^he also has a maf. So please don't talk down to him like he is wrong about what sensor he replaced, when you clearly need to read up yourself.

 

[EuroFanatic]

Hmm...I thought the engine and the sidewalk were the same thing as well... Oh wait, that's my Associates Degree in Automotive Technology and Repair Talking...

Thanks everyone, I thought I was going to have to break out my picture book... Oh here it is...

First pic is my current status, clutch replacement. Second is the location in relation to the TB, and 3rd is the part number right off the part.

I have tried as much as I can think of for this, and I am at a loss. Had a neighbor who is a tec h come take a look, and he got stumped as well. The engine is 100% stock, exhaust has 3" pipe.

 

[nated420]

How about your iac valve it could be bad.

 

[EuroFanatic]

I get to go through the testing process of everything tomorrow. Got the clutch in it today and atleast its running. How are Eclipse clutch's supposed to feel? The pedal has to be almost entirely to the floor just to shift. Every other car I have owned only has to be maybe 1/4 of the way down. Bled it for like an hour and the pedal feel did not change, nor was there any visible air.

Also, I have the WGS restrictor removed, but my boost gauge is only showing a max of 9psi (connector is plugged in) No boost leaks found from my homemade tester. Ideas?

 

[EuroFanatic]

Ok. so I have gone through some more testing to eliminate sensors, and I haven't found anything. I let the car sit for a while tonight, and decided to take a video right after start up. The spots in the video where the car idles at about 1k and at about 1.5k are actually full throttle, no idea why the RPM wont increase, just sits there and misfires. Done this on 2 sets of wires and 3 sets of plugs. It will idle and miss like that, and then either drop waay low, or continue to rev up.

Once the car hits normal operating temp, it idles mostly smooth at 750rpm with the typical random look at me rev up. A slight miss when warm, but not too bad, also I noticed today that when cruising at a steady speed it feels like a slight bucking going on...

<iframe width="420" height="315" src="http://www.youtube.com/embed/hZV7BRfDKXw?rel=0" frameborder="0" allowfullscreen></iframe>

 

[mb3000]

I have actually been reading about this for a little while tonight...

Can I attach a multimeter to it like the ISC to get an Ohm reading, or any other way to diagnose it? I would assume it would have different readings for hot and cold.

Also, the ISC appears to have 6 terminals on it, but the descriptions for testing it talks about 4 terminals...is there an image to use for which terminals to check?

I was looking around, and I see information related to a Talon doing a similar problem...could the Coolant temp sensor cause idle issues when cold, and once warm it becomes fine again?

Stealth 316 - ISC Servo Motro

 

[EuroFanatic]

Hey! That looks exactly like what I am looking at! Thanks, Ill go try this out.

If that diagram is also specifically for 2G Eclipses.... I have readings of 0, 28, 28, and 0. Should be 30's Ohms on all...

 

[mb3000]

I would suggest replacing your ISC.

DSMISC Automotive (New ISC Supplier)

 

[Jay95GST]

I had a similar issue but it turned out to be my Cruise Control cable was getting stuck and leaving my throttle open.