Starters

Everything you should know about VW starters and solenoids*: http://forums.vwvortex.com/showthread.php?2359900.

The above link includes:

1. How it's made
2. Upgrading
3. Replaceable parts
4. Troubleshooting

• Lots of starter issues are wiring related
• Sometimes it starts, others not
• Starter stays on even when driving or after the car is shut off
• It grinds like a mofo!
• Ok the starter is out, how do I know if it's good?
• Slowwwww cranking
• The starter spins, but doesn't engage the flywheel

5. Replacing the starter

*Diesel starter is shown/used in that link.  Diesel starters contain reduction gear sets and are larger and heavier than gasoline starters.

Intermittent Starting

Causes and remedies:

• Ignition switch is faulty.  Replace ignition switch.
• Starter is faulty.  Replace starter.
• Faulty battery cables and/or electrical connections.  Replace battery cables and/or clean/repair electrical connections.  Be sure the ground connections are good.  Note: Replacing the battery cables is a wise idea whether or not your car is suffering from starting issues.
• 1990+: Coolant temp sensor (CTS) is faulty.  Replace blue CTS.
• Cabriolets with automatic transmissions:

• Not starting when hot: Starter is suffering from heat-soak.  Install a hot-start relay and be sure the heat shield is in place.
• Intermittent starting: Starter-interlock system is faulty.  Replace or bypass the interlock relay.

• Fuel pumps are overheating.  Replace fuel pumps.
• Fuel pump relay is faulty.  Replace relay.

No Start

Common causes:

• No spark
• Faulty/wet distributor cap, rotor, and/or spark plug wires
• Weak coil
• Faulty ignition switch
• Defective Hall sender
• Incorrect ignition timing
• Broken timing belt
• Faulty fuel system
• Engine mechanical failure

For complete diagnostic procedures for all of the above, please refer to your Bentley Service Manual (or other repair manual).

No Re-Start When Hot

Is it an automatic? Automatic Cabriolets are notorious for this problem due to the poorly-located starter (next to the exhaust manifold).  The best solution for this problem is to install a starter relay: click here for a how-to.  Also, be sure that the heat-shield is in place.

Spark Plugs

NOTES:

• The above cross-reference chart is a guide only; please verify the part numbers prior to purchasing/installing.
• Original factory plugs: Bosch WR7DS and W7DTC.
• 1 This plug has been discontinued by Bosch.
• Firing order: 1-3-4-2
• Spark plug gap: 0.028"/0.7mm.  Remove the screw-on tips (if the plugs came with them installed) before installing your new plugs.
• Copper or platinum is all these cars require; no need for the expensive iridiums.  Single or triple?  Either works well; choose which one works best with your car.
• Bosch no longer makes good spark plugs; Champions are good, but NGKs are best.
• "Use BP6ET and nothing else" is often said to folks whose cars fail emissions tests.  Bottom line is this: ANY new plug you install will be better than the old ones in the car.  And again, use what works best with your car; my '86 does not like triple, non-resistor platinums, it prefers resistor single platinums or coppers; the opposite could be true for your car.

Distributors

Ignition Control Unit Pin-outs