Shuttering in stock 240?

[agentunkind]

OK im new to the 240's and piston engines, I have a '93 RX-7 and all I know is the rotary. Anyways, the car I just got is a '90 240sx in fair condition. I changed oil, plugs, wires, fluids, valve cover gasket and checked compression which was a steady 165 all across. Now the main problem I have is a squeal from the belts, and the car shutters emensly after being revved. Say i rev the car to 4k and let it come back down it will shutter for a few seconds at about 1k or so. Would this possibly be related to a dirty fuel fileter or what would be causing this? Any more info can be provided if u ask.

Alex

[USCS14DUDE]

does it shake when you cut if off, i had a friend that had something similar and it was a motor mount

[agentunkind]

Not really, only time it shakes is after letting off the gas more soo if it's a quick rev of the engine to above 3.5 k. Its noticeable after driving a bit and thne letting off the gas but its not as sevre as if I rev it and then just let off the gas.

Alex

[adrock]

Check for vacuum leaks. After doing all that work under the hood you may have knocked something loose. One area to pay close attention to is beneath the air intake hose that comes from the front near the radiator, around the power steering pump and near the main eccs intake. There are lots of little interconnecting vacuum lines in there. Make sure that your flexible intake hose is attached securely to the manifold and sealed by the clamp- if it has partially come loose it will fool your airflow sensor.

It never hurts to replace the fuel filter- I'd say you're probably looking at an easy fix, it just might take some double checking. Good luck.

-adam

[Toddles82]

if it shakes after a hard rev when it's coming down it's most likely a motor mount.