Tuesday, June 23, 2015

Rough Idle Troubleshooting

Spent some considerable time troubleshooting a rough/loping low idle.  Ran fuel flow tests, cleaned all the fuel injector nozzles, checked for bubbles in the fuel line from the fuel pump to the flow divider, inspected all plugs, and replaced all ignition cables on electronic ignition side.  Traced it down to the vacuum advance on the electronic ignition.  At low idle, the high vacuum was sensitive to the pulses from the cylinder cycle since the vacuum port is so close to the intake valve on the cylinder.  Ordered a .004" Snubber from McMaster Carr and put that right on the vacuum sensor port, and the idle smoothed right out.

Spent some time making brackets and cleaning up the ignition wire routing while I was at it.

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