j200pruf

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.

FCmaniac

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

j200pruf

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

FCmaniac

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.

j200pruf

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.

j200pruf

please, I have no clue!!!

j200pruf

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

mazdaspeed7

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

j200pruf

Hey Adam, I found that one of my fuel lines has a slight kink in it . 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?

mazdaspeed7

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.