misfiring / vibrating at low revs

[BananaBoy]

Hi guys!

I've to say I love this board, I've been reading it for a while and now it was time to sign up couse:

My VS is not running very well lately. The problem is when I rev it up a bit over idle in neutral (and keep it at ~1200 rpm) I can feel heavy virbrations troughout the whole car. But the block is not jumping or anything and the vibrating is very .... harmonic. Besides that it also happens when driving, on accelerating or slowing down only at that specific rotations. If I get out of that rotations everything is fine again.

Furthermore if I rev it up very fast to 2000 or 3000 repeatedly I can hear it slightly misfire in the exhaust when the revs go down again. When I play a bit around with the gas I can get a nice bang out of the exhaust. And it seems to be worse when it's hot. (not sure on that) Also the exhaust fumes smell a bit like petrol.

I dont know if the misfiring and the vibrating are the same problem.
Besides that it is running fine and has heaps of power.

What I did so far:

Checked the plug leads - one was a bit loose on the coil pack (not on the notch).
Checked the spark plugs - all are fine exept one (replaced it).
Checked underinflation hoses and all connectors.
Not using any water/oil. No liquids are mixing. Does not overheat.
Everything else looks good so far.

The local mechanic told me the vibrating is from worn out engine mounts. I mean yeah they aren't new anymore but somehow I doubt that that will fix it.

Any ideas?

[theSeekerr]

Well, he could be right - my VR used to be fine. Went in for a check before rego, apparently one of the engine mounts was cracked. 3 days (!) and a new set of engine mounts later, it has exactly the vibration problem you describe, although at about 1800 revs. No misfire, so I'm guessing that's unrelated.

[BananaBoy]

Hmmm I checked the error codes and it comes up with:

12 -ok
76 - Air Fuel Ratio between left right banks
97 - Canister Purge Solenoid and or circulit

I got no clue

[BananaBoy]

ok regarding that 97 I found a loose hose and a loose connector (wtf?) on the left back of the engine ... migt be the TPCV.

that leaves still the 76 which might explain the misfiring and the petrol smell.

[BananaBoy]

ok I found it. The switch seems to be cracked and it lost pressure there, I just put a screw in the hose and it is running fine now.
Also the 76 does not come up anymore just the 97 which seems to be right couse the switch is broken.
Too easy.