Hey all, I am still having a crappy vibration with my car, but noticed something odd. When I first start the car after it has been sitting for a while (it has to get completely cold), and I start the car is smooth as glass for about 10-30 seconds (haven't really timed it). But as the car gets warmer the vibration gets worse. This vibration happens wheather the clutch pedal is pushed down or not. It seems to get worse with RPM (only have gone to 4k) but not much, when under load (like leaving going up the hill on my street) the vibration seems stronger, but not faster) And it is bad enough that when standing outside of my car you can see the steering wheel vibrating, looking some what like a guitar string.



Specs on car, fairly fresh rebuild, put under 100 miles on it so far, but I have let it run quite a bit. S4 NA, mazdatrix competition motor mounts, rebuilt trans, new clutch and p-plate, light aluminum flywheel.

You sure its not the comp mounts are just that stiff?

I don't see how the mounts would be really smooth for about 30-seconds and then making it vibrate.

hmm I don't know, I put urethane MM's in my other car and the wheel vibrates worse as the RPM goes up. How about your trans mounts? When you start the car for those first 30 seconds, isn't the rpm up a bit and then drops down? The vibration could go away at a certain rpm and then come back.

When I start up the AWS goes to 3 grand, I tap the gas up to 4k and I can feel nothing, let it go down to idle, still no vibes. I can blip it to 4k and back down to idle about 3-4 times before I can feel the vibration.

please, I have no clue!!!

one last bump to the top, then I am giving up.

Check your plugs, coils, wires, and your fuel injectors. Its more likely a dirty injector than the ignition stuff, but its worth checking anyways.

Hey Adam, I found that one of my fuel lines has a slight kink in it https://www.nopistons.com/forums/pub...1047683664.gif. It is the hose that comes off of the dashpot looking thing on the end of the secondary fuel rail, could this be the issue?

It could be. That would affect your fuel pressure, if its kinked, the FPR wouldnt see engine vacuum and wouldnt lower the fuel pressure accordingly.



Replace that vacuum line, and see how it is.

It's the fuel line that is kinked, the vacuum hose it fine.

does it act up when you're drivin, like vibrations driving? my car makes a lot of vibrations if it's sitting with the clutch out in nuetral. then smooths out somewhat after being put in gear with the clutch in.

Sitting, Driving, clutch in or out, in gear or not it vibrates, you don't really notice it at idle but once you get to 2,500 you can tell it's there get's pretyt bad at 4k, but I am not running the motor over 4k yet.



But I still don't know for the life of me why it would be glass smooth when it's cold. I will be fixing that fuel line, replacing the fuel filter, plugs and wires here shortly.

Are you sure the counterweight that came with the alum flywheel is for an S4?

my car did this exact same ******* thing all last year.. mysterious vibration that would sometimes go away, sometimes not..

I couldn't figure it out for the life of me, still haven't... hopefully its gone when I put everything back together this year.

If I remember right the part number that came with the counterweight was the S4 part number.

OH MY GAWD!!!! I took some advice from a friend on the RX7club (BlackRx7, thanks A LOT if you are on this forum as well!) and took off the crossmember and remounted it. AND IT FIXED IT, HOT DAMN!!! https://www.nopistons.com/forums/pub...IR#>/bigok.gif https://www.nopistons.com/forums/pub...#>/biggrin.png https://www.nopistons.com/forums/pub...1047683329.gif



I just took it out for a https://www.nopistons.com/forums/pub...1047683473.gif and the vibration was gone, holy **** now I just need to finish up a few odds and ends and put this bitch back on the road.