Current state:
M/c fixed the vacuum leak. Lean condition became Rich condition that he is investigating now. I tried to suggest that the computer needs to re-learn! He also did not test fuel pressure.
Fuel Trim - Originally:
1500 rpm 2500 rpm
LTFT 6.2 6.2
STFT 6.2 8.6
After I disconnected the battery and let all the Capacitors discharge:
LTFT - 4.6
STFT - 7.8 - 12.5
Originally:
- idle random misfire P0300, P0304 and occasionally P0303
- Changed spark/ front O2 sensor (OEM) - Spark is platinum a level up from OEM
- Changed cap/rotor, spark wires with aftermarket parts - still misfire
- Swapped the Dizzy coil but still misfires
- Engine compartment is dry except Dizzy neeeded a new O ring - took care
- Compression was good 175 to 190 (renage 135 to 199)
- M/c did the leak down test and no issues
- I added S1 fuel injector cleaner and the car started running fine (for a day!) but then misfiring closer to 2400rpm on road and not on P gear. Misfires on all Cylinders. Basically it misfires at idle and stops once warmed up. But on the road, it misfired around 2400rpm.
- Owned the car for over 15yrs with little issues.Last yr IACV had to be cleaned. Carbon build up stopped its functions temp - after cleaning it started running like a new car. Throttle body is clean.
- Use Mobil 1 5W30 every 5k.
- valves adjusted 22k miles ago
- air filter has 8k
- Spark plugs did not show any abnormality
- Batt and Alternator tested fine
- cold start gives gas smell through exhaust even before the misfire
- only known issue is the car would need jump start if you don’t drive for 2 weeks
Related thread:
https://community.cartalk.com/t/are-the-cap-rotor-still-good/175532
Update:
I did edit here and there and added new info.