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On 29 Sep 2006 at 12:00, Chris Sheridan wrote: > I bought a 1970 FI automatic Fastback 7 years ago and put about 50k on it > with nothing more than routine tuneups. Granted the cold start valved had > been disabled - previous owner had told me when it was hooked up it would > flood the motor. So all those years I was never happy with my idle - it was > always a bit rough with a miss. > > Then last year I thought I blew the transmission - no go in any gear - had > it towed home and pulled the drivetrain, had a spare type 4 auto trans which > I switched in after swapping the axles flanges. Bought a new longblock from > AVP since mine was due for a rebuild. Installed new motor and spare trans > and found out that the transmission was not bad it was just a stripped axle > stub on the rear right wheel. Replaced that and I'm back to daily driving. It's a shame you went to all that trouble and now find yourself in this jam. The problem is probably just one of mis-matched parts. Each version of the AT is set up to expect the kind of vacuum at its vacuum modulator that the engine it was supposed to work with would have provided. My guess is that this is where your problem arises, but it's not clear that a solution exists. I would start by adjusting the vacuum modulator according to the type 4 AT instructions. That may or may not get you closer to a solution, but that's where I would start. > I brought it into a shop to have it properly tuned. They replaced the air > distrib box adj screw and reconnected the cold start valve. Down the road I > go. It runs great on the highway, but then when I slow down and get to a > stop sign it stalls out. > > When it drive position it barely idles, when I put it in neutral the idle is > much better although still kind of stallish. I suspected I could just tweak > the timing up a bit, when I looked at it, I discovered that the new engine > is a code X 1972 engine. The old distributor I've been using is a Manual > Transmission 1969 distrib numbers ending '001' - not the stock distrib for a > 70 auto. That distributor should be fine if you will just time it to TDC. > When I shine the timing light on it I notice that it's timed to 7.5 btdc > when I know that this distrib is supposed to be timed to 0 degrees. However > I cannot retard the timing as the condensor barrel is snug against the fan > housing and will not retard. This is probably an indication that the distributor drive gear is installed in the beetle position rather than the type 3 position. With care, this can be corrected with the engine in the car. Note to the wary: NEVER turn the engine in the forward direction with the distributor removed. Once the drive gear is installed correctly, you will probably have to move the SP wires to their correct locations in the dist cap. > Also, it sounds and behaves like the timing is too retarded when in the > drive position at a stop light. I was thinking advance the timing but I'm > loath to do that if it's already 7 points advanced from what the bentley > wants. Just make sure that the mechanical advance is not frozen. > I have not tried to adjust the idle speed yet. How bad is it to have the > application distributor on there? > > The second issue is with the T-4 Transmission I swapped in. It works fine > except sometimes it shifts from 2nd to 3rd multiple times based on my > depressin the gas pedal, if I am very gradual with the acceleration I can > usually avoid it, but it often will shift up then do it a 2nd or 3rd time > which is kind of annoying > > anyone had these problems before? I'm afraid you've probably created a unique situation. You're on virgin territory. I know it's a lot of work, but the only CERTAIN solution would be to put the type 3 AT back in, get the drive gear in there right, and time it to TDC. -- ******************************* Jim Adney, jadney@vwtype3.org Madison, Wisconsin, USA ******************************* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ List info at http://www.vwtype3.org/list | mailto:gregm@vwtype3.org ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~