Just wanted to take a minute a post about a great diagnostic tool I discovered on The Samba a few years ago. I've probably posted about it before but it's worth mentioning again.

<http://www.thesamba.com/vw/forum/viewtopic.php?t=349429&postdays=0&postorder=asc&start=0>

While driving home one day my van started bucking and jerking like someone was toggling a switch. I barely made it home. Soon after my van refused to start at all. The starter cranked just fine but nothing from the engine. 

At this point I did what most people do, pop the hood, or engine cover in this case, and stare mindlessly at the engine hoping the solution would just pop into my head, which, it kinda did. I remembered about a year before building this diagnostic tool for another no-start issue. So I hooked it up, per instructions, and vroom, the engine purred to life! At that point I started disconnecting the three leads one at a time (again, following instructions). 

First lead I removed was to the coil. Fired right up. Second was the lead to the ECU relay. Nothing. Cool, we're getting somewhere! Hooked it back up and disconnected the lead to the fuel pump. Fired right up. So, I determined that the issue lies with the wiring related to the ECU relay. 

After consulting the Bentley wiring diagram (ouch, my brain hurts) I determine what wires go where. First I probe the hot lead (red wire, always hot) going to the relay. It's hot as it should be. Next I check the black lead that activates the relay when the key is turned on. Nothing. According to Bentley, this wire comes from the coil. I start probing the wire at several points. Nothing. I determined that the connection at the coil is hot (with key on) so it has to be the push-on connector itself. I break away the plastic shield from the connector and find it to be green and corroded. Not too surprising on an old Vanagon. I snip the old connector off and crimp on a new one. Vrooooom, the engine comes to life! Sweet! 

The credit for this great tool goes to crazyvwvanman (Mark) on The Samba. Thanks!

Mark K
1986 GL/2WD/4SPD "Abe"
1991 GL/2WD/4SPD "project"