Autostick troubleshooting

- G
- globenospam
  
  Contact options for registered users
posted
20 years ago

Sat, Jul 12, 2003 10:10 PM

My '69 autostick Ghia won't go into gear. It had been driving fine. I left it parked for about an hour after driving it, and was just able to get it into gear and drive home. Subsequently it wouldn't go into gear at all.

When I pull the vacuum hoses off the control valve in the engine compartment, there is no sound of vacuum escaping. Also, the engine races (more than normal) initially when it is first started, and then almost stalls when it goes to slow idle. (The idle had been perfect before the shifting problem started.) This seems to me to indicate a major vacuum leak somewhere.

I have tried replacing all the vacuum hoses, including the one from the control valve to the clutch servo. I pulled away the engine compartment trim and had a look at the vacuum tank. It doesn't seem to have any rust or holes. I have two control valves and have tried them both. The transmission won't shift with either one.

Last year I had a shop replace the rubber seal in the clutch servo itself. I am beginning to wonder if that repair has gone bad. It's also possible that both the control valves I have are bad.

Does anyone know any tests for tracking down the source of the vacuum leak? I don't want to start taking stuff apart or spending money without trying to narrow down the source of the leak a bit more. Or is it possible a major transmission failure could have the same symptoms? (I doubt it's a major failure, though, because it happened so suddenly, and the car has only 54,000 original miles. It does seem more like a vacuum leak.)

Any comments would be welcome. Thanks. R. Addinall

(To reply directly remove nospam from the e-mail address)

- J
- Joey Tribiani
  
  Contact options for registered users
Vote on answer
posted
20 years ago

Sat, Jul 12, 2003 11:10 PM

On Sat, 12 Jul 2003 22:10:19 GMT, snipped-for-privacy@interlog.com ran around screaming and yelling:

i had a 71sb with autostick...i had to replace the servo boot several times before i finally found out the local vw shop was selling me a "universal" type boot...i went to an old vw mechanic and bought a vw part for it...never had another problem...the "universal" boot was much taller than the stock one causing the vaccum to suck the rubber up tight to the vaccum inlet...it would "pop" the new rubber one pretty quickly...

first start the car...let it run a bit....shut the engine off...turn key back on and move the shifter(as if to select a gear) you should

*hear* the servo under the car pull the clutch...if you hear it move *with* a hissing sound, the boot is shot...if you don't hear the hissing sound move the shifter between neutral and a gear three to four times...the vaccum tank holds enough vaccum for three to four shifts after the engine is shut off... if when you do the above "test" and you hear *nothing*(make sure ignition switch is in the on position) you either have dirty contact points in the shifter(or possible broken wire) or your control valve is bad...you can check the control valve with a test light...clip the end on the positive wire at the servo, then put the point on the other wire...move the shifter(with key on) and the light should light up...if it does, then contacts are good....if it doesn't its time to disassemble the shifter and lightly sand the contact points.... good luck.... Joey

- M
- Masqqqqqqq
  
  Contact options for registered users
Vote on answer
posted
20 years ago

Sun, Jul 13, 2003 3:17 PM

You should have vacuum escaping from the hose from the servo to the intake manifold, when you disconnect it at the servo. The fact the idle sucks now seems to indicate a broken hose, or some other uncontrolled vacuum leak into the intake manifold. Check the entire intake manifold for cracks, tight fittings, etc. Is it a dual port engine? check the intake manifold connection boots. Check the carburetor gasket. You replaced the hoses....did the old ones looked cracked? Did you put the hose from the servo to the proper vacuum port? It should be the lowest one on the setup, probably cut right into the back of the intake manifold pipe, below the carburetor.