idle adjustment..

[bbob203]

what would cause the need to have to change the idle from its factory setting?

[bajacalal]

Mainly, the fact that the injection pump slowly wears out over time.

There are other small factors though, major changes in ambient temperature and pressure, changes in fuel formulation...

[bbob203]

the problem i'm having is a bad vibration. i replaced the front motor mount the one by the radiator because it was bad.. I as well as the p/o(just bought the car a month ago) thought that would fix the problem... well it didnt. now I'm moving onto the other two. I did try adjusting the idle to see if that would help but i have to turn it up so high to get rid of the vibration i thought it was to high for comfort. What could be causing it besides the idle being off or the mounts being bad. I timed it by ear and its better than what it was when i bought it the guy timed it with a guage but i think he left it a little bit retarded because it didnt run good and vibrated more than it does now.

[ORCoaster]

If you ever remove the pump and reinstall it you have moved the position off it's setting and getting it just right to where it was prior is a wee bit tough to do it seems.  Especially for those that can't measure the advance setting with a gauge and just have to set it by ear. 

As to the shake shimmy and rock and roll problem.  Do you know for sure that the other mounts are collapsed and not doing their job?  Loosen all points of contact.  Front bracket you just touched, the two bolts on the side mounts and the two bolts in the bottom of the transmission mount.  Wiggle the engine back and forth and front to back.  Get it to settle in square.  Look up from the front of the car and see if the transmission mount is caddy wompas.  Get it straight and then tighten the two on the sides.  Then push up a bit on the front one and tighten that down. 

Now try starting it.  Does it still jump around like popcorn in a hot skillet?  Drive it a bit and see how it does when warmed up and sitting at a light.  Bearable or not? 

You may have an injector fouling and when cold it does it more than when warm.  That might be throwing the balance off and getting the shake down from that. 

OK, out of ideas.  Anyone else care to coach?

[bbob203]

Took out other 2 mounts, 1 is definitely bad(the big doughnut one on the passenger side) it could be worse i guess but i will replace it, the other one(trans mount) i cannot tell if it bad or not but i think it may be the original one its oem/vw even if it isnt. going to replace it for good measure since i took it out. While i was at i went nuts and seperated my exhaust and took out the the shifter box and all, going to replace all the bushings and such. since that mount being out of the way opened up so much space im going to throw in a p/s rack loop while I'm at it as well because it will be way easier than the one on my other car. When i put the mounts in i will definitely do what you suggested to make sure everything is seated and lined up how it supposed to be. This thread is turning into more of a build thread already.

[Baron VonZeppelin]

Not that its part of your problem or not.

When the fuel filter hits last leg the idle will get lower, power will go down, usually some/more pronounced smoke.

New mounts would be sweet whether it ever shook the dash or not.

You haven't ridden on the edge until you get into a Mk1 Dzl that registers on the richter scale - even the door lock knobs were coming unscrewed. Thats some shaking right there now buddy.

[bbob203]

Not that its part of your problem or not.

When the fuel filter hits last leg the idle will get lower, power will go down, usually some/more pronounced smoke.

New mounts would be sweet whether it ever shook the dash or not.

You haven't ridden on the edge until you get into a Mk1 Dzl that registers on the richter scale - even the door lock knobs were coming unscrewed. Thats some shaking right there now buddy.

its almost that bad lol. Fuel filter is brand new by the way has 500 miles on it almost exactly. 

[theman53]

My first rabbit had trouble with fuel. I went through a bunch of fuel filters in one month and then about 1 filter a month for a while. It would get so bad the car would shut off. I did the one filter a month until probably 7 months later then it was back to normal. All the engine mounts were junk. I remember one time going to a private lake that has a gate house you have to stop in and talk to a person to get in. I was yelling and she couldn't understand me. My friend was laughing so hard in the passenger seat, but I didn't know it until I shut the car off to talk to the lady. Makes me laugh thinking back on it.