I have a 1982 380SEL, that is having engine power issues, but the symptoms are giving me trouble in diagnosing the cause. I commute 60 miles a day, 30 each way - this is my daily driver.
Always runs strong on the way to work, 75mph, much of it flat or down hill. All the power I need. On rare occasions, I get the symptoms occurring in the last 10 miles of the drive - so well after the car has warmed up.
On the way home from work in the evening the drive starts out solid engine power, but the problems begin at highway speeds of about 55mph+ and continue all the way home, both at high a low speeds (once the symptoms have started) My driveway is a couple hundred feet with a slight uphill, and at times I can hardly get the car up the hill)
It feels like someone has a rope tied to the back of car and keep tugging on it. I lose enough power that my speed will slowly need to decrease to about 55phm, a speed which I can then maintain but with the same pulsing, lunging feel.
Initially I though fuel injectors - ran cleaner through with no improvement.
Inspected distributor cap, which was in terrible shape. Replace Cap and rotor thinking that could be affecting timing, and thus leading to the power issues. I replaced the fuel pump about 3 years ago.
Could it be
- throttle body icing (I'm skeptical of this as I can pull off the freeway, turn the car off, let the car rest, prsumably melt any icing, but the engine power issues will persist even at slow speeds getting back to the freeway)
- weak fuel pump
Is there some climate compensation unit that could be failing?
Any other ideas would be greatly appreciated.
Car details - 366k miles, engine rebuilt at about 200K. Over the last 5 years I've put in a new radiator, starter, fuel pump, distributor cap, rotor, 1 lifter on passenger side that had stated sticking. I replace the plugs yearly, and oil+filter change every 3000k.
Always runs strong on the way to work, 75mph, much of it flat or down hill. All the power I need. On rare occasions, I get the symptoms occurring in the last 10 miles of the drive - so well after the car has warmed up.
On the way home from work in the evening the drive starts out solid engine power, but the problems begin at highway speeds of about 55mph+ and continue all the way home, both at high a low speeds (once the symptoms have started) My driveway is a couple hundred feet with a slight uphill, and at times I can hardly get the car up the hill)
It feels like someone has a rope tied to the back of car and keep tugging on it. I lose enough power that my speed will slowly need to decrease to about 55phm, a speed which I can then maintain but with the same pulsing, lunging feel.
Initially I though fuel injectors - ran cleaner through with no improvement.
Inspected distributor cap, which was in terrible shape. Replace Cap and rotor thinking that could be affecting timing, and thus leading to the power issues. I replaced the fuel pump about 3 years ago.
Could it be
- throttle body icing (I'm skeptical of this as I can pull off the freeway, turn the car off, let the car rest, prsumably melt any icing, but the engine power issues will persist even at slow speeds getting back to the freeway)
- weak fuel pump
Is there some climate compensation unit that could be failing?
Any other ideas would be greatly appreciated.
Car details - 366k miles, engine rebuilt at about 200K. Over the last 5 years I've put in a new radiator, starter, fuel pump, distributor cap, rotor, 1 lifter on passenger side that had stated sticking. I replace the plugs yearly, and oil+filter change every 3000k.
