I've been trying to troubleshoot occasional bucking/lurching, an issue that had gotten worse over the past few weeks. We want to take the bus for a camping trip tomorrow, so the pressure is on to find the culprit. This is a 1975 VW bus with fuel injection, pretty much stock except for a Pertronix module instead of points.
On Tuesday, I decided to drive the bus to work. The bucking was quite aggravating, but I made it to work on time and back. In the evening, in the safety of my garage, I did the following:
- I tended to the ground connections of the FI wiring harness (2 connectors on top of the engine case, by the air intake plenum; 1 to the firewall near the resistors and double relay; hope I didn't miss any other).
- I checked the voltage between the + (15) terminal of the coil and ground with the ignition on. Oddly, it was just some millivolts. Scratched my head. Turned the ignition off. Then turned it back on and cranked the engine: it started easily. Measured tension again, engine running, and got 13.4 V. Turned engine off, but left ignition on. Measured again and got 12.2 V. Weird.
It's like a mystery novel and I'm running out of clues. :)
Thanks for reading.