Ignition Randomly Stops in Megajolt Lite Jr Installation

[MacAlberich]

I purchased a prebuilt Megajolt Lite Jr unit directly from Autosport Labs back in April of 2013. The system was working with no problems when we originally installed it last year but now, after taking the vehicle out of winter storage, is experiencing ignition "drops" where the entire ignition system stops working momentarily and suddenly.

The problem began demonstrating itself as I was idling the vehicle (I have not attempted to drive it due to this problem). The tachometer will dip from ~1,250 RPM to 0 immediately and the exhaust usually backfires as unburnt fuel is dumped into it. The ignition will often return one moment later and the engine returns immediately to idle. The intervals between instances of this problem occurring appears to be random; I was unable to identify any logical pattern to them. Eventually the engine will stop completely. The fuel pump will continue to run (demonstrating that the electrical system in general is still working) even after the engine quits. In these cases, I have been able to immediately restart the engine with no problem.

The Megajolt unit continues to display an unblinking green light throughout the entire process described above. However, the laptop I have been using to run the configuration software previously has not picking up any data from the unit since I began trying to diagnose this problem. It was providing data as intended last year before I put the car into storage. (Storage was in an enclosed garage - I have examined the vehicle and garage for evidence of possible water ingress during the winter and found none.)

I have performed the following steps so far in my attempts at a diagnosis:

- Visual checks of the wiring connections. No loose wire noted.
- Using a multimeter to confirm connectivity on the wiring. No problems detected.
- Visual examination of the ignition switch wiring. No loose wiring found.
- Reinstallation of the configuration software to the laptop, along with replacement of the cable used to connect the laptop to the Megajolt unit. No change.
- Replacement of the Ford EDIS unit. No change.

This appears to be the same problem previously described by a different person in the Hardware and Installation post "Megajolt randomly cuts out" (http://www.autosportlabs.org/viewtopic.php?t=3893) but no resolution was posted in that thread.

For reference, the engine involved is a VW ABA 4-cylinder unit from the mid '90's.

[brentp]

Hi Mac,

Thanks for contacting us.

First thing to do is to test without the Megajolt connected to the engine. the EDIS module will control the engine at 10 degrees 'limp home mode'. Verify that you still experience the dropout conditions. If so, you've isolated the Megajolt from the problem and you'll need to focus on the EDIS components.

If you still experience the dropout, then check the wiring for the VR sensor, and the gap between the VR sensor and trigger wheel, and also check the gap between the trigger wheel and sensor.