'87 Chevy Celebrity, 2.5l l4 with Throttle body injection, distributorless ignition system, automatic trans. 97,000 miles. OBD 1 isn't showing any codes.
I bought this car a month ago with brake issues, a broken brake hose(Solved with your videos :D), and running rough due to improperly gapped spark plugs. The plugs were fixed but now when it gets to operating temp it jerks when trying to accelerate and stalls if I don't let up on the gas or when I come to a complete stop. I took off the air cleaner and noticed white smoke coming from the throttle body (from running rich i think.)
Would the period of running with improperly gapped plugs have ruined the oxygen sensor and caused these issues?
Well if you have smoke coming out of the throttle that's under the hood. That generally means the engine is flat worn out and it's throwing blow by. Remove the spark plugs and do a wet and dry compression test of the engine to see if the engine is just flat worn out
I hope you didn't buy this 38-year-old thing to use as a daily driver.
Be sure to check your fuel filter and fuel system pressure. Also as @scotty says do a wet/dry compression test to make sure you're not fighting internal engine problems.
If you're running too rich that would show up as excess carbon or even wet gas on the spark plugs. The O2 sensor will be the old narrow-band type and can be tested with a multimeter:
https://www.youtube.com/watch?v=Jfd_6MPD36o
It's also quite possible the throttle body injectors are not functioning properly due to partial clogging or wear/age. This video details how the system works which may help in diagnosis:
https://www.youtube.com/watch?v=2k0NVN6fndY
I wonder if it's possible to test if the oxygen sensor is causing the issue by unplugging it's electrical connector? I would think doing so would cause the engine to run in open loop and stop using the oxygen sensor for fuel control.
