1990 Mercury Grand Marquis Q&A
1990 Mercury Grand Marquis Question: 1990 mercury grand marquis is starting in gear
the car seems like it is in gear even though i am starting it in neutral and then it dies before I can get anything done. any ideas? - Visitor
This car has a mechanical vacuum operated automatic transmission. Also, it utilizes a throttle valve cable to make sure pressure remain appropriate during vehicle operation, dependent on throttle position. If the grommet that holds the TV cable to the throttle breaks and the cable becomes detached, then quick damage can occur in the transmission. I would look there first. However, if the transmission is in gear while in park or neutral, there is assuredly some internal damage. Get a diagnosis performed locally by a qualified transmission expert. - DaveJHM
The throttle position sensor (TPS) may fail. Common symptoms of a defective TPS can be rough idle, hard starting, hesitation on acceleration, poor fuel economy, and stalling.
Wear on the rear axle shafts near the bearings can create excessive play and lead to gear oil leaking past the seals. Gear oil will leak onto the brake backing plate, brakes, and wheels.
when car shifts to overdrive and you let off the gas the transmisson kicks out of gear like it was shifted to neutral give it a lot of gas it starts working again 123 &reverse work fine only does ...
when car shifts to 4th and you let off gas it quits pulling you have to give it a lot of gas for it to start pulling again already changed fluid and filter