Ignition System Troubleshooting

Introduction
If you've come to this procedure, you probably suspect that you have a no spark condition. If so, you should have already verified that you actually have a no spark condition by performing the initial "no spark" test described in TS-01, Troubleshooting - Engine Will Not Start.
There are many different ways to go about testing for a no spark condition. The only problem in determining the ultimate cause of a no spark condition is that if the condition is caused by a problem with the DME computer, there's really no way to conclusively test the DME. The same is true with a no fuel condition. So, what we have to do is determine, as best we can, whether the DME is getting power and whether it's getting all of the correct input signals it requires to run the engine. If we get all of the proper inputs and the DME is still not providing the desired output (i.e. spark from the ignition coil or running the fuel pump), we make the assumption that the DME computer is bad and we replace it.
One of the best ways to test the DME computer is to swap it for a known good DME computer. However, most of us don't have the luxury of keeping a spare DME computer on hand. However, if you suspect that starting or running problem may be due to a bad DME computer, try to borrow a computer to test your car before running out and buying a DME.
Tools

• Mulitmeter
• Test lead jumpers