idling problem 3

[bhw33191]

ok so its not so much an idling problem anymore so much as a "running" problem in general. I've was working on my car for about 4 hours today and found many problems, which fixed everything, then more problems were found. "But i guess thats expected with a car this old thats had no work done." I replaced the vacuum hoses which seemed to help a lot, but wasn't 100%. Then i just decided to replace the rotor and cap "which was a good idea" because components inside it were melted and torn apart. Thought for sure this would help. Took it for a ride, then the check engine light went on and immediately started running like crap. Stopped at walmart parking lot and fiddled with some wires, check engine light went out and the car ran almost perfect. I then sped away from the parking lot amazed to feel POWER!!.....but then i stop at the intersection and what do ya know! the light goes back on and the rpm's fall, economy gauge moves around as a result. I now have reason to believe that this could be the O2 sensor? I moved it around and every time the engine light would go out. "Afterall it has never been replaced and HAS touched the hot engine before which i guess is bad."

[silicon212]

Those only last 20k-30k miles so if it's original, it can't hurt to replace it. They're about $20.

[PeteA216]

Suggestion on the O2 sensor... Stay away from bosch. I usually have good luck with bosch, but not with O2 sensors. I went through two in about a month because they kept foulling out for some reason. I bit the bullet and bought the $50.00 A/C Delco one from Nu-Way auto parts. It lasted me 2 years until I removed the ECM from my Caprice and now the same O2 sensor I took out of the Caprice from Nu-Way is running in my truck just fine for a little over a year now.

[silicon212]

Hmm ... I've used nothing but Bosch and have replaced it twice in the time I've had the car, ~80k miles.

[PeteA216]

In the words of Chris Farley: "Well la dee freakin' da"... I'm just kidding. Maybe there was something else wrong with my engine causing them to go bad, or it could have been it was something I was doing, maybe neverseeze accidently getting on the sensor itself or something. I was getting horrible gas mileage and black-ish/brown-ish smoke from the tailpipe occationally during accelleration. I changed the O2 sensor with a bosch... ran mint! Clear exhaust, halfway decent mileage... but that only lasted about 3 weeks (or so) before the gas mileage started declining again. Changed the O2 sensor again... same thing, worked great for a few weeks and headed south again. When I got the A/C Delco sensor the mileage went back up once again, and the exhaust was clear... stayed this way up until I removed the ECM which was almost two years after the whole O2 sensor ordeal. I saved that O2 sensor, and it's in my truck now. Luck of the draw maybe.

Try bosch. If it works out, great! If not then... uh... I just lost my train of thought.

[j cAT]

I've used bosch O2 ,,but that was about 10years ago...I had no problems..perhaps the O2 sensors produced by bosch recently have a defect... these sensors are guaranteed ...

[bhw33191]

ohp! too late! i already bought it. This really sucks because the car is still running crappy, engine light is still on, but it IS running better. I think i'm going to check to see if theres any crap in the fuel filter and replace the EGR. I also have a question on this sensor which is all melted as if it shorted out. Its connected to the carb and sits right in front of it. Seems to be some sort of thermostat but i'm going to post a thread later with a picture so maybe someone can figure out what it is.

[PeteA216]

Check what the engine code says. It'll probably lead you right to the issue. If the check engine light comes on in syncronization with the engine running poorly, then the odds are against it being a dirty fuel filter. That sensor you're talking about very well may be the culprit.

Update on O2 sensor theory of mine... Maybe Bosch didn't work out for me because I never had my A.I.R. system hooked up and the tubes were just clamped off. The lack of air going into the exhaust may have caused them to foul out prematurely for me.

[bhw33191]

Originally Posted by PeteA216

Check what the engine code says. It'll probably lead you right to the issue. If the check engine light comes on in syncronization with the engine running poorly, then the odds are against it being a dirty fuel filter. That sensor you're talking about very well may be the culprit.

Update on O2 sensor theory of mine... Maybe Bosch didn't work out for me because I never had my A.I.R. system hooked up and the tubes were just clamped off. The lack of air going into the exhaust may have caused them to foul out prematurely for me.

So about the code thing, if i'm not mistaken, isn;t there a way for me to check the codes myself and not have to bring it to a mechanic? I thought you could put a paperclip in the diagnostic port somehow. I believe mike posted something about that.

[silicon212]

Originally Posted by bhw33191

So about the code thing, if i'm not mistaken, isn;t there a way for me to check the codes myself and not have to bring it to a mechanic? I thought you could put a paperclip in the diagnostic port somehow. I believe mike posted something about that.

Jumper terminals A&B on the ALDL under the dash. Turn the key to "ON" but DO NOT START THE ENGINE. Each code will flash its sequence 3 times, starting with a 'Code 12' followed by the codes you are looking for. Each code will flash on the light in a sequence - i.e. a Code 12 will be one flash, short pause, two flashes, longer pause, repeated 3 times.

[bhw33191]

Originally Posted by silicon212

Jumper terminals A&B on the ALDL under the dash. Turn the key to "ON" but DO NOT START THE ENGINE. Each code will flash its sequence 3 times, starting with a 'Code 12' followed by the codes you are looking for. Each code will flash on the light in a sequence - i.e. a Code 12 will be one flash, short pause, two flashes, longer pause, repeated 3 times.

Ok, so what do you mean when you say "jumper terminals A&B? I'm assuming ALDL is the diagnostics port?

[silicon212]

ALDL = Assembly Line Diagnostic Link, yes it's the terminal block under the dash on the driver side. A and B are the two terminals on the top row, on the right side.

[PeteA216]

Nowadays, at least around here, it's hard to find a mechanic who still had an OBDI Reader. It's insteresting to watch though and see how much information a computer that's 20+ years old actually deals with and handles as you flip through the different functions on the reader. I'm talking about the ones that do more than simply read codes.

[j cAT]

Originally Posted by PeteA216

Check what the engine code says. It'll probably lead you right to the issue. If the check engine light comes on in syncronization with the engine running poorly, then the odds are against it being a dirty fuel filter. That sensor you're talking about very well may be the culprit.

Update on O2 sensor theory of mine... Maybe Bosch didn't work out for me because I never had my A.I.R. system hooked up and the tubes were just clamped off. The lack of air going into the exhaust may have caused them to foul out prematurely for me.

the air pump is used to give the cat a good supply of oxygen to aid in its ability to remove the hydocarbons ...on a good running engine this is usually at cold start up...


If the EGR or the mixture is wrong because of some component too rich it is possible to foul the O2 with carbon deposits


gas tank vapor /canister purge diapham with a hole in it can cause a poor running engine..

[bhw33191]

Originally Posted by PeteA216

Nowadays, at least around here, it's hard to find a mechanic who still had an OBDI Reader. It's insteresting to watch though and see how much information a computer that's 20+ years old actually deals with and handles as you flip through the different functions on the reader. I'm talking about the ones that do more than simply read codes.

Yeah i know what you mean. Its truly amazing how these cars even have computers the way i look at it.