I have 1992 Buick LeSabre with 300,000 miles and it runs great except when it shifts to overdrive on most any type of incline, it seems to lag somewhat. The whole fuel system has been replaced, as we
I am curious if maybe the timing belt may be a little loose and it is not keeping it's proper timing when put under a load. If I let off the gas gently so that it will downshift, and then accelerate, it runs smooth again.
Home Security - Dayco - 600l050 Synchro-cog Timing Belt