emax02

iTrader: (1)

Ok, I took my SC off and my car is all back together now, but the damn thing is still stalling out all the time! It seems a little worse too. Heres what happens, I start the car up and it runs smooth as silk and idles perfectly but then when I go out for a ride after about 3miles the car starts to shake while it is in gear, now if I put the car in nuetral when it does this the car will stall right out every time, why? I took a look at my spark plugs today and the tips off them are real black and there only about 2000 miles old. I cleaned 3 of them as best I could and then went out for a ride and the problem was still there. So at this point I have no idea what is going on and I am starting to get very worried. I do no that my car was running very rich when I had my SC on because of the black stuff on my Exaust pipe. One other thing when my car gets into it's chuging then stalling mode I get this oily smell from under the hood.

Please help! Thanks

Weasel

iTrader: (2)

Not an expert but...

I think what's happening is your ECU is still adjusting to the new lesser airflow. With the SC it had to pump the maximum amount of fuel to keep up with the air from the SC. Now it's got to go back to the normal level, and it may not have adapted yet.

emax02

iTrader: (1)

Thanks for your .02 cents, but I did clear my ecu, so whould'nt that cancel out your idea then? Also my car was acting funny before I took the SC off{atleast I know theres nothing wrong with the SC}

BTW there is no check engine light on. I am wondering if maybe it is a o2 sensor in the exaust some where? But if that was the case whoud'nt my check engine light be one? Some one please try to help me out I am going nuts over here! Thanks a TON! Ohh BTW since my car was running so rich whould'nt that destroy a o2 sensor rather rapidly?

Daniel B. Martin

There are two degrees of failure.

1) The Oxygen Sensor is "dead".
The signal from the Oxygen Sensor is outside the normal range, or completely absent. The Engine Control Module (the computer) turns on the Malfunction Indicator Light and stores one or more Diagnostic Trouble Codes. This failure mode is obvious because of the dashboard warning light.

A dead Oxygen Sensor is a severe failure and should be repaired promptly.

2) The Oxygen Sensor is "tired".
The Oxygen Sensor still works but it responds slowly to changes in the oxygen concentration in the exhaust stream. There is no MIL or DTC. This failure mode is less obvious. The symptoms are increased fuel consumption, decreased engine power, and a feeling of sluggishness. The throttle response is not crisp, like it was when the car was new. An Oxygen Sensor may become tired due to high mileage or being "poisoned" by exposure to various substances including leaded fuels, anti-freeze, anti-seize, RTV sealants, and the residue of burned engine oil. A "tired" Oxygen Sensor is still doing its job, but not performing well.

A tired Oxygen Sensor is not a severe failure and the car may be operated safely.


You may have your Oxygen Sensor(s) tested. There are electronic testers made for this specific purpose. In addition, a technician with an automotive oscilloscope can test Oxygen Sensors. The signal from a healthy sensor varies from a low threshold (around 0.2 volts) to a high threshold (around 0.8 volts), and it sweeps back and forth between those extremes about 10 times per second. If the scope trace shows the Oxygen Sensor signal failing to reach either extreme, or oscillating between them at a frequency slower than 10 cycles per second, that is evidence of a "tired" sensor.

I've read that a bad Oxygen Sensor can sometimes be rejuvenated by removing it, clamping it in a vise, and heating the sensing tip red hot with a propane torch. This is said to burn off a crust of deposits which interfere with its operation. I've never tried this torch trick myself, so cannot vouch for it's effectiveness. If you have a sensor which is already dead, you have little to lose.

For more information about Oxygen Sensors see:
http://www.volksparts.com/o2sensors.htm
http://members.aol.com/carleyware/library/o2sensor.htm

Daniel B. Martin

A "bad idle and stalling" problem may arise from ...
- a vacuum leak
- a stuck-open Exhaust Gas Recirculation valve
- a stuck-open Positive Crankcase Ventilation valve

The reason your engine runs well for the first few miles of operation is that the rich mixture the Engine Control Module delivers to a cold engine compensates for the lean mixture which is a consequence of a vacuum leak. When the engine reaches normal operating temperature the engine management system goes into Closed Loop mode and the rich mixture is discontinued.

Daniel B. Martin

You took off the supercharger. Did you remove everything associated with the supercharger? Are you running with a non-stock fuel pump or fuel pressure regulator? These items could result in an over-rich mixture in a normally-aspirated engine.

Sprint

iTrader: (10)

so you took the S/C off and still same problem eh? i say you should have kept the S/C but hey..

emax02

iTrader: (1)

Thanks a ton for your great info Daniel B., I greatly appreciate it. I did manage to fix the problem!!! At last, what I did was just replace the spark plugs and the car runs perfect! I took it out for a 20 mile ride and it seems to be 100% fine! I guess the problem was a carbon build up on spark plugs which caused these problems. Few I so happy this crap is over, the lessen I learned is that when you put a SC on you better get it tuned or else your car will be running way to rich and problems will arise.

Incase anyone is wondering the SC is sold so no more boost over here. Ohh well I am thinking about getting a 2002 max now and invest a little later 260 NA Horse Power and a 6 spd sound offly tempting.

Sprint

iTrader: (10)

when you first installed your SC did you put in new plugs? because spark plugs, oil filter and your fuel filter should have been change at exactly that time..

Vic

try changing all your plugs instead of cleaning them. most likely they're fried. DBM's is also right about the O2 sensors' if your seeing black sh|t coming out of your muffler, you may have fried your plug/cat/o2/muffler.
I changed all the plugs when i went back to stock.
The stillen SC does run mad rich, thats why I tuned mine with a adjustable regulator and warned everyone with the SC.
Another problem I ran into when I uninstalled my SC was something simple... plugged a vacuum hose into the wrong port =P. try to find someone and compare hoods! good luck.
Vic

emax02

iTrader: (1)

Thanks Vic, I don't know if you read my last post, because my car is working 100% now, no more stalling, what I did was just put in some new plugs. My old plugs were completly covered with black crap, AKA Carbon Build up. Ohh and about comparing it to another max, I have a 95 Max and used it a ton! I love that car, I have got to let it go though .

Sprint, I still have my original fuel filter on my I30 which has 45K miles on it, I changed my plugs, oil and oil filter when I put my SC on.

Stephen

I'm not sure if I responded to this elsewhere, but when I had stalling problems, had the ac valve replaced. This is related to emissions.