The engine revs and rpm go up but wont go faster then 40mph

SOURCE: can't locate fluid eservoir to add trans fluid

Here how to do it: If you see no signs of leaking from the transmission then the level is probably not low, take it to a transmission shop, transmission repair on this car is not for the DYI.

Ensure that the transaxle case temperature is 70° to 90° F (21° to 32° C). With the engine running, shift transmission through all gears. With engine idling in PARK, remove the check plug from the transmission. If transmission has been overfilled, allow fluid to drain out. If no fluid drains out, add fluid through the TRANS FLUID fill cap under the hood on the driver side in 1 pint (0.5 liter) increments until it slightly flows from the check plug. Reinstall the check plug.

SOURCE: will not accelerate wont even rev past 3500 rpm's

i have a ford fairmont 95 ef that rattles when i accelerate sounds like chains on a bike clunking and wen i put my foot down it wont revv any higher than 3500 rpm and keept jerking about like it was tryna risist going faster and before u ask me yes the car was in drive so it wasnt because i forgot to change gear if any one can help me as to wat the problem might be it would be very much appreciated

SOURCE: wont rev up

If your check engine light is on pull the codes.

If not it may be your tps sensor.

SOURCE: 1984 Nissan 300zx non turbo VG30E engine wont rev

My vg30 dnt rev more than. 2200

SOURCE: 1987 mercury grand marquis tends to stall an not

All the above things mentioned are possible. I would personally start with the fuel filter. And if you haven't had a tune up for a while I would consider it. Before the tuneup though I would check the catalytic converter. A fuel filter problem will act like it is cutting out, especially at the higher speeds. The catalytic converter will act like the engine is bogged down even in idle and in park. I haven't seen a fuel filter make the engine rev up and down, but I have seen the catalytic converter do this, usually it is slight. If yours is up and down at around 400 to 500 rpms I would suspect the idle air control motor. Since it is going up and down the motor is working, so probably just needs a cleaning. Also clean the port that goes to the engine. Some are deep, so it doesn't hurt to use a rod (like a coat hanger ) to clean the engine port. Brake clean works best for cleaning these and the throttle body.