Running Rich?

[98_DSM]

I have a 98 Eclipse GS (auto) with a CAI, everything else is stock. Ever since I bought the car it has been getting really bad gas mileage. I average 220miles to a full tank, and in my opinion that is not right. Yesterday I had a friend following me down the road when he called me and told my my ehxuast blew a bit of black smoke when I started from a dead stop. When I had the car home I left it running and checked the exhaust to see if there was any smoke. I could not see anything so I placed my hand in front of the muffler tip to see if any gas built up on my hand. Once I placed my hand in front of the muffler tip I could see a bit of smoke, but not enough to be able to tell what color it was. You can't smell gas when the car runs and it does not smell like oil either it smells like a normal amount of exhaust fume is exiting like it should be. Also no gas or fluid of any kind built up on my hand and I held it there for a few minutes.

I do have an issue with my O2 sensor 1 on bank 1, I'm getting a CEL from that sensor about a heating issue?? I have replaced this sensor once and it did not fix the issue so I'm going to guess I have something else wrong. I know a bad O2 sensor will cause some bad gas mileage but as bad as I'm getting I kind of doubt it, if I'm wrong please somebody tell me.

Also after the car has warmed up and I sit at a traffic light for example in DRIVE the car will idle rough. I'm going to guess at normal operating temperatures the car idles between 800-900 RPM. When the car is warmed up sometimes it will idle at 500-600 RPM. If it starts to idle rough like that I can put the car in Nuetral and it will go back up to the 800-900RPM range. When my friend informed me about the black smoke from my ehxuast I was experiancing the rough 500-600RPM idle. Could the O2 sensor be causing this issue?

From what I understand when these cars get a CEL they go into Loop Mode?? Or Limp Mode?? I can't remember what it is called, and ECU tells the car to pretty much dump gas. If I'm wrong please somebody correct me on this so I don't have false information. Things I have done to try and correct these issues, I have replaced the spark plugs (NGK Copper Core), spark plug wires (Value Craft), installed the CAI (Ebay CAI) in place of the stock intake system (Filter is in the fender in front of the tire), and an oil change (Castrol GTX High Mileage 10w30). If anybody can give me ideas or inform me on anything I might have wrong please do so I would be greatful for any help.

 

[98_DSM]

Also I went off of what Autozone told me to gap the spark plugs at, and I don't know if I want to trust them. Anybody have that info off hand, what to gap the plugs at on a 420A?

 

[4UH8ERS]

Your spark plug gap needs to be at about .048 and as far as your running rich issue is concerned if you have already replaced the upstream o2 sensor you need to replace the coolant temp sensor. Thats the larger of the 2 sensors on the water outlet (a.k.a thermostat housing). You see a faulty CTS will communicate to the ECU that the car is not warmed up past 150 degrees and will remain in open loop, causing you to run extremely rich about a 14.7:1 a/f ratio.

 

[98_DSM]

Ok I think everything is fixed, there was a series of things I checked and corrected to get where I'm at now. First off I called up to get prices on the O2 sensor from the dealer, and it was almost $300.00 so I said F that! Then I asked them the proper gap on the spark plugs for my car, they asked me for my VIN and told me between .050 and .052 on the spark plugs. So if anybody asks the proper gap on the spark plugs for a 420A in the 2G Eclipse is .050-.052. And I was also told tha Champion spark plugs might be better for the engine than the NGK's that I use. Anyways I called up the Autozone I bought the O2 sensor from, they told me that another local Autozone had four of my O2 sensors, so I call the other Autozone to make sure that they did have the sensor in stock. Turns out that they had one OEM replacement and three of the universal sensors. I figured I would just get another OEM fit sensor. I get there and the sensor they give me is the wrong sensor, I have a circular connector and the OEM fitted one is a square connector. So the Autozone guy decided to do some research for me, and found out that between 97 and 98 the N/T Eclipse went through some changes, and some of the early 98's used the O2 sensor from the 97 Eclipse. So they had the 97 sensor in stock and SHAZAM! It was a perfect fit to my car!!!! And at the same time I got $13.00 back because the 97 sensor was cheaper than the 98 sensor. I had them clear my CEL, I then checked my spark plug gap, and to my suprise all my spark plugs where at .020 when they where supposed to be pre gapped for my car. So I gapped them to .050 put everything back together, started the car up and almost instantly the car seems to run better than it ever had before.

Shortly after I finished doing all of this I was sitting in the Mc Donalds drive through and my exhaust started pouring out white/blue smoke. It did that for a few minutes, I figured I shot my piston rings so on the way home I drove it like I stole it. Ever since then the car has not smoked one bit and my rough idle went away, and I can already tell it is getting better gas mileage. My guess for the smoke was the ECU adjusting everything to the new sensor??? Or should I be looking out for possible issues in the future? Anyways so far everything is running great so thanks to everybody for listening and lending their personal information, if my CEL does not come on in the next four days I will call this case closed.

 

[98_DSM]

Your spark plug gap needs to be at about .048 and as far as your running rich issue is concerned if you have already replaced the upstream o2 sensor you need to replace the coolant temp sensor. Thats the larger of the 2 sensors on the water outlet (a.k.a thermostat housing). You see a faulty CTS will communicate to the ECU that the car is not warmed up past 150 degrees and will remain in open loop, causing you to run extremely rich about a 14.7:1 a/f ratio.

CEL came on tonight again on a quick run to Wal-Mart..... Welcome to the wonderful world of the DSM, I'll have the CEL checked tomorrow on my lunch break. I wish I could find my scanner but at the moment it is lost. I'm leaning towards what your talking about with the coolant temp sensor. But wouldn't the ECU throw a CEL for that sensor if it was bad?

 

[4UH8ERS]

CEL came on tonight again on a quick run to Wal-Mart..... Welcome to the wonderful world of the DSM, I'll have the CEL checked tomorrow on my lunch break. I wish I could find my scanner but at the moment it is lost. I'm leaning towards what your talking about with the coolant temp sensor. But wouldn't the ECU throw a CEL for that sensor if it was bad?

Yes, it will throw a code. The problem is its a generic code when you go to an auto parts store and not a dealer specific code. The CTS failure is usually going to pull an air/fuel meter generic code cause of the rich condition. Which is why you are gettin gthe upstream o2 sensor code.

 

[98_DSM]

Yes, it will throw a code. The problem is its a generic code when you go to an auto parts store and not a dealer specific code. The CTS failure is usually going to pull an air/fuel meter generic code cause of the rich condition. Which is why you are gettin gthe upstream o2 sensor code.

Looking the code up online I found a few things about P0135: Oxygen O2 Sensor Heater Circuit Malfunction (Bank 1, Sensor 1)
************************************************************
This code refers to the front oxygen sensor on Bank 1. The heated circuit in the oxygen sensor decreases time needed to enter closed loop. As the O2 heater reaches operating temperature, the oxygen sensor responds by switching according to oxygen content of the exhaust surrounding it. The ECM tracks how long it takes for the oxygen sensor to begin switching. It the ECM determines (based on coolant temp) that too much time elapsed before the oxygen sensor began operating properly, it will set P0135.

O2 Heater element resistance is high
Internal short or open in the heater element
O2 heater circuit wiring high resistance
open or short to ground in the wiring harness

Repair short or open or high resistance in wiring harness or harness connectors
Replace oxygen sensor (cannot repair open or short that occurs internally to sensor)
*************************************************************
I have already replaced the O2 sensor twice now, so there must be a short or open wire in my harness somewhere.

I called up the lot I bought the car from today and he told me to bring the car down this Friday and they will hook it up to their computer to find out the exact issue. So I just have to survive until Friday and drive the car to Branson. Where they will hook up an actual digonostic machine to the car and tell me what is up.

 

[98_DSM]

**UPDATE**

First off I would like to find out who the last owner of this car was, because I would love to ask them why the hell they did what they did to the car. Because I'm almost 100% positive that I found out what is wrong with my car. I went out to test the sensor harness with a volt meter to see if I was getting a 12v current on one of the wires. When I got the harness in my hand I noticed that there was a fifth wire coming out of the protective plastic sheild of the harness. Knowing there is supposed to be only four wires not five I decided to remove the sheild some. Only to find out that somebody had spliced into the black wire on the harness and taped it up. I took the spliced wire off and sure enough the wire was bare, and next to it a red/black wire was partialy cut with some green buildup around the copper bare wires. Also I noticed that the cover to the cars main wire harness was lose, so I poped it off to find a cut wire in the main harness, and that somebody had ran that cut wire somewhere else. This car has so many spliced and cut wires I'm very surpised that the damn thing runs at all. This car is a f*cking death trap on wheels as far as I'm concerned. I have not noticed any of this because one, I have had the car a little over a month and the time that I have had the car the weather has not allowed me to do a good search over the car. Two, when you buy a car you never think about the main wire harness being hacked up. So now I'm pretty much going to trace EVERY wire in the main harness and see what kind of damage the asshat before me did to this car. Which leads me to ask this, does anybody have a wire diagram for these cars?? If not then hopefully a repair manual will and I'll have to pick one up this Friday when I get paid.

 

[4UH8ERS]

Did you even test the CTS? it would take you all of 2 seconds. Secondly if spliced/crimped wires wrapped in electrical tape piss you off, dont even start removing wire looms and tracing interior wires because they come like that from the factory, extremely poor electrical wiring like that all over these cars.

 

[98_DSM]

Did you even test the CTS? it would take you all of 2 seconds. Secondly if spliced/crimped wires wrapped in electrical tape piss you off, dont even start removing wire looms and tracing interior wires because they come like that from the factory, extremely poor electrical wiring like that all over these cars.

How do you test the CTS, if it takes all of 2 seconds to do it I would like to know how. Do I clear the CEL, unplug the CTS, and start the car and see what the CEL reads after that? Or is there another method to do this?

 

[4UH8ERS]

How do you test the CTS, if it takes all of 2 seconds to do it I would like to know how. Do I clear the CEL, unplug the CTS, and start the car and see what the CEL reads after that? Or is there another method to do this?

Well, I dont have my haynes manual on me at work here, but I am pretty sure the ECU uses the resistance at the sensor to determine temperatures. Just take your multimeter out and back probe the sensor with the key to the on position. Fire up the vehicle and make sure your resistance changes as the temperature increases. If anyone has the actual FSm testing procedure please post it for this fella.

 

[garputo2]

Ok I think everything is fixed, there was a series of things I checked and corrected to get where I'm at now. First off I called up to get prices on the O2 sensor from the dealer, and it was almost $300.00 so I said F that! Then I asked them the proper gap on the spark plugs for my car, they asked me for my VIN and told me between .050 and .052 on the spark plugs. So if anybody asks the proper gap on the spark plugs for a 420A in the 2G Eclipse is .050-.052. And I was also told tha Champion spark plugs might be better for the engine than the NGK's that I use. Anyways I called up the Autozone I bought the O2 sensor from, they told me that another local Autozone had four of my O2 sensors, so I call the other Autozone to make sure that they did have the sensor in stock. Turns out that they had one OEM replacement and three of the universal sensors. I figured I would just get another OEM fit sensor. I get there and the sensor they give me is the wrong sensor, I have a circular connector and the OEM fitted one is a square connector. So the Autozone guy decided to do some research for me, and found out that between 97 and 98 the N/T Eclipse went through some changes, and some of the early 98's used the O2 sensor from the 97 Eclipse. So they had the 97 sensor in stock and SHAZAM! It was a perfect fit to my car!!!! And at the same time I got $13.00 back because the 97 sensor was cheaper than the 98 sensor. I had them clear my CEL, I then checked my spark plug gap, and to my suprise all my spark plugs where at .020 when they where supposed to be pre gapped for my car. So I gapped them to .050 put everything back together, started the car up and almost instantly the car seems to run better than it ever had before.

Shortly after I finished doing all of this I was sitting in the Mc Donalds drive through and my exhaust started pouring out white/blue smoke. It did that for a few minutes, I figured I shot my piston rings so on the way home I drove it like I stole it. Ever since then the car has not smoked one bit and my rough idle went away, and I can already tell it is getting better gas mileage. My guess for the smoke was the ECU adjusting everything to the new sensor??? Or should I be looking out for possible issues in the future? Anyways so far everything is running great so thanks to everybody for listening and lending their personal information, if my CEL does not come on in the next four days I will call this case closed.

Just to let you know no spark plugs are pre gapped and .20 is correct for turbo cars

 

[idomin8-420a]

Just to let you know no spark plugs are pre gapped and .20 is correct for turbo cars

he's a 420a n/t

 

[tazman_tn]

One little thought.... I know this probably has nothing to do with your problem at hand, but you need better plug wires, especially if you ever push your car hard. I used Autozone wires on my talon for a little while, but kept getting an engine miss after a month or two. I swapped them out and it ran fine for month or two. Same problem occurred again so I swapped for third set. And again, same thing happened. I gave the wires back to the zone for refund and got the belden max wires from napa.... been running them over a year now without a problem.... and i push my car hard, and give it 7k rpms. just my thought