Runs worse after replacing O2 Senor/plugs?

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1987 Chevy Sprint. 1.0L 3 Cylinder, not turbo, 174K
Recently I took out the o2 sensor, and put a new one in. Old one was basically a burnt crisp on the ends.. Problem was I only tightened as much as my fingers could, I didn't have a socket to put it back in. Anyway, I put new spark plugs in..Started it up and it chugs a bit. I think my timing is off as well, probably 60 or so degrees, because the Notch doesn't even stop anywhere close to the Markings on the timing belt case. Also , the old sparkplugs had some oil on the ends, diagnosis?

posted by  Devon1299

How can you have your timing off, knowingly, and ask why does your car run bad? 60 degrees? It's wont even run that far off. I'm betting anything over 20 degrees off - in the BTDC direction is the maximum the car will even run at.

posted by  DodgeRida67

Just curious incase I'm in that situation ever, how did you get it out? :screwy:

posted by  DodgeRida67

Cut the wire, then used a 7/8 socket to run it out...

posted by  Devon1299

First things first, What prompted you to replace the o2 sensor? Was the check engine light on? Why the plugs?Was it running bad to start?

Lastly, tighten the o2 sensor first. The socket is available at any parts store for a minimun amount of cash, some even offer it as a rental tool if you are low on cash. You should always finish one repair, before starting the next, if not you only buy more trouble.

posted by  hitchhiker

most O2 sensors should be tightened to 25-30 ft-lbs with antisieze such as Permatex 133k or Felpro C5-A used on the threads.

I am going to base my thinking on the 87 sprint a feedback carb.

Make sure the firing order is correct

Next, @ 174K, I would do a compression test and see if there are any major issues which need to be adressed.

next check for vacume leaks @ the intake, and where the throttle body connects to the intake. Also check your vacume lines.

use a calibrated spark checker to verify you are getting enough voltage from the ignition system to properly fire the engine. If not come back and we will help trouble shoot

Pull the trouble codes. I copied this from since is has simple instructions

1987-88 VEHICLES

1. Turn the ignition key ON. The CHECK ENGINE light should illuminate but not flash.
2. Reach under the dash and turn the diagnosis switch ON. If the CHECK ENGINE light remains ON steady or goes out, the ECM is defective or poor contact exists between the ECM wires.
3. If the CHECK ENGINE light flashes, codes are stored in the system. Record the flashes and check the diagnostic code list. (Refer to "Diagnostic Trouble Codes-Feedback System" in this Section for more information.)
4. Turn the diagnosis switch OFF after all codes have been recorded.
5. Stored fault codes may be erased from memory at any time by removing power from the ECM for at least 30 seconds. This time period must be increased as the temperature drops. It may be necessary to clear stored codes during diagnosis to check for any recurrence during a test drive, but the stored codes must be written down when retrieved. The codes may still be required for subsequent troubleshooting. Whenever a repair is complete, the stored codes must be erased and the vehicle test driven to confirm correct operation and repair.

when you get your trouble codes, come back and we will help interpret them

posted by  tbaxleyjr

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