My 1988 Alfa 75 3.0 V6 seems to be bogging under acceleration. After reaching operating temperature, it can run fine for a few minutes (plenty of power), but then it frequently has a few bad minutes where it has no power, jerks and hesitates with acceleration and sometimes backfires with a pop. It seems to run poorly after a few minutes of driving.
The car hasn’t been run properly in about 7 years. I had an issue with the fuel injector o-rings leaking air causing a misfire. I’ve since replaced these and it’s now running on all 6 cylinders. (before I replaced the o-rings, the bogging issue was significantly worse).
Another issue is that the car is VERY slow to start – turn the engine for 10 seconds, stop, then try again after a few seconds and immediately almost comes to life but then back to just cranking. Can take 20 seconds of turning engine before it eventually comes to life.
Idle is okay, but every so often runs rough for a few seconds. This occurs during the warmup and then again after the car has been running for a while.
Any ideas would be appreciated!