2G 2GNT Weird idle lope

[benspilk09]

My 99 eclipse just started having a really lopey idle the other day, really sounds like it has aftermarket cams or something. It also has a miss at low rpm when the a/c turns on, or any other time when the engine is loaded below 2000 rpm. I have a new coil pack, new plugs and wires, passed vacuum leak test, cam timing is spot on (checked it several times after I put my new belt on), compression is over 200 on all cylinders, cleaned the throttle body and IAC and it appears to be in working order, cleaned the EGR system as well. I don't know where to go next, guess I should start putting sensors on it? Which one should I try? Here is a video of my car: YouTube - 420a Eclipse idle problem

 

[Colt4G63 also]

I would just test everything first and see what's wrong. You could waste a lot of time and money by just throwing parts at it. I didn't see any concrete test results in your original post. Is it throwing any codes?

 

[benspilk09]

Nope, no codes. The IAC motor tested fine with a volt meter, as did the coil pack. My manual doesn't really go over how to test the other sensors though. A few months ago it had the EGR insufficient flow code, but it has not come back. I cleaned the EGR system and it seems to work fine now. Forgot to mention that it goes down the road just fine, just idles like this. The plugs are NGK's too.

 

[13b Bro]

I had the same type of problem and it turned out it was the throttle stop switch not working correctly. Also make sure that it is adjusted right and not holding the throttle plate open slightly.

 

[benspilk09]

Well now its being a whole different problem, It wants to idle at around 2000-2500 rpm. I have done nothing to it since the video either, so I am puzzled. It idles perfect until it gets warmed up, then it throws its fit. The idle also straightens out when you force the engine down to idle speed, like using the clutch to slow down the engine to normal speed then it just stays there. The temperature and humidity changed quite a bit since the video, and has always seemed to have a great effect on how the car runs so maybe the intake air temp. sensor? I took it out and cleaned it with electronic parts cleaner and it did nothing, along with the MAP sensor. Still runs the same.

By the way what do you mean by throttle stop switch? I guess I'm not aware of any such switch on the car.

 

[13b Bro]

Make sure nothing is holding the throttle plate open. Not familiar with 420a but on my GSX it is the switch on the top of the throttle body that tells the ecu that the throttle plate is closed.

 

[jericho777]

My 99 eclipse just started having a really lopey idle the other day, really sounds like it has aftermarket cams or something. It also has a miss at low rpm when the a/c turns on, or any other time when the engine is loaded below 2000 rpm. I have a new coil pack, new plugs and wires, passed vacuum leak test, cam timing is spot on (checked it several times after I put my new belt on), compression is over 200 on all cylinders, cleaned the throttle body and IAC and it appears to be in working order, cleaned the EGR system as well. I don't know where to go next, guess I should start putting sensors on it? Which one should I try? Here is a video of my car: YouTube - 420a Eclipse idle problem

My 96 n/t is diong the same thing it's been doing it for 3 years. It had a brand new engine. Now it's throwing p0171 code and is knocking severely. I've checked sensors replaced the o2 sensor and fuel filter. There is also a high pitched continuos noise coming fron the ecu when the key is on and for a couple of minutes after the key is turned off. I've had enough now it's in the shop. How's your fuel pressure regulator/fuel pump? Any vaccuum leaks? Could be your ecu too.

 

[benspilk09]

I have sort of been leaning toward ECU lately, No vacuum leaks and no nothing is holding the throttle open. Fuel pump and stuff seems fine since it pulls like normal, just runs like crap at low rpm.

 

[420aPJ]

Bringing back an old thread. I have the same problem and nothing i have tried from this thread is working. Wondering if you figured out the problem or if anyone has.

 

[Fotowntalon]

figured this should have already been checked, but throwing it out there anyways because it wasn't mention and because the OP said it wanted to idle at 2-2.5k. Have either of you tried to check/replace the TPS?

On a side note, the OP's car sounds very close to mine =P

 

[fallenangel]

What spark plugs are you running? What are they gapped at? This may be your issue or I can also suggest you look into regulating your acceleration/throttle. Do you find that the rpms vary in idle? Do the rpms drop significantly and when you press the clutch it stabilizes? My car was having the same problem and it turns out that I had to replace my throttle cable and adjust the acceleration and bam, problem no more. I hope this helps! Good Luck!

 

[NeMiZiS]

Mine likes to lope a little bit too.
Never much bothered me though, doesn't really seem to effect anything but the idle.

 

[Bluefire16]

Sounds silly, but if you plugged in a spark wire in wrong order it can cause this.

 

[NeMiZiS]

Sounds silly, but if you plugged in a spark wire in wrong order it can cause this.

That is pretty hard to do with a 420A.

 

[benspilk09]

I ended up replacing my ignition coil after checking it with a multi meter and finding it was out of spec. It didn't fix it immediatly but a few days later it had cleared up, and hasn't done it for almost a year now. I have no idea if the coil pack helped it or not since it wasn't an immediate fix, but it runs fine now and that's the only thing I replaced.

 

[97talon83]

my 97 talon does this too, i have been leaning toward either my ecu or ignition.... it cant be my plugs or wires because i did a complete tune up when i bought it, just a few suggestions

 

[Shake_Zulla]

Most of the time this problem is due to a leak in the intake. I've seen a couple times when it has been the ecu but it's not that common. People say that they do a leak test but a lot of the time they don't know how to do it or they don't check the bottom of the intake where it bolts to the head because it's hard to get to. IMO if you have any problem change the gasket between the TB and intake. Its about 3 bucks and takes 5 min. Then blow smoke around your intake and see if any gets sucked in. Not saying that it is the problem but seals for your intake will run you about 10 bucks and thats a lot cheaper than an ecu.

 

[Tigerhorns]

+1 on sounding good