purerx7

iTrader: (61)

I have had my car for about 4000 miles now. When I am curising at lets say 50, the rpm will go from 1500, drop to about 1000 for maybe 6 secs, and than shoot back up to 2000, its not as long if i give it any gas. It seems to be bogging really bad. I do not know if the fuel filter is bad or not, but the last guy who had the car definetly looked liked a cocaine dealer, so maintenace wise i dont think the fuel filter nor transmission fluid has ever been placed. So its my throttle response and bogging a proble because of the fuel filter or is it something else?

turbojeff

iTrader: (30)

Change the fuel filter anyway but it is not your problem.

Is your car an auto?

purerx7

iTrader: (61)

ya, its an auto

adam c

iTrader: (2)

When you buy a used car, maintenence is always a question. Unless you know for a fact that the maintenence has been done, you must assume it has not been done. That means that you have to do it. You should replace all fluids:

coolant
oil
rear end
tranny

You should inspect and replace if necessary:

belts
hoses
spark plugs
air filter

Replace the fuel filter.

Sonny

As soon as I got my car, I parked it. I put it in the garage on jackstands. It sat there for over a month while I did the following:

Fuel Filter
Silicon hose job
Mazda fuel line recall kit
Fuel pulsation damper
Fuel injector overhaul
Check valve testing/replacement
Solenoid testing/replacement
Rewrapping of the main engine harness
Fuel pressure gauge installation
Fuel pressure regulator testing
Spark plugs
Spark plug wires
New oil + filter
New coolant
New transmission oil
New differential oil
New airbox filter/airbox mod
New oxygen sensor
Installation of an aluminum AST (air separator tank)
Brake booster line/check valve

It was a lot of work, but my car has been good to me since then.

Most (if not all) of the above should be mandatory work on a used car with an unknown maintenance history. (IMO)

Sonny