CATBELLEW

Help! Rough idle without spark at #4 and #1. New plugs, wires, dist cap, rotor and coil. What's up with this?

Thanks!

mazdaverx7

i would check the cap and make sure none of the contacts are damaged on the inside. it's happened in the past but its very unlikely. however, we need more details on the year of your car and the model. 924, 944 or 968?

CATBELLEW

Ok, new dist cap checked out factory nice. This is a 944 Turbo S bone stock. Was running fine as I pulled away from the garage then less than 1/4 mile into my drive to the store it started missing. Brought it back home and started the hunt. No spark at #1 and #4 so it's running on #2 and #3 and you know what it sounds like...
Could it be DME, DME relay, ref sensor? I'm baffled!

CATBELLEW

Sorry , forgot to add it is 1988 model Turbo S with 82K on the clock.

dontnow

Swap plugs and see if the misfire follows the plugs. Swap out the cables one by one and see if changes. Always best to retrace your steps when something goes bad. HTH

Cochezz

REFERENCE OR SPEED SENSOR

Test with Ohm meter

PITA to change if you have big hands.