94-95 Mustangs Engine Timing
From Mustang-Tech
Contents |
Timing Theory
As the engine's RPM increases, the engine must fire its spark earlier to allow time to properly burn the fuel in the combustion chamber. The EEC-IV processor works by monitoring engine load and adjusting when the sparkplug for each cylinder fires.
The EEC-IV processors expect the base timing to be set at 10 degrees before top dead center. In order to properly set this base timing, the computer must be disallowed from making adjustments on the fly to the timing. The method for doing this is to unplug a jumper in the engine bay called the SPOUT connector, short for SPark OUTput. The computer will not be able to advance the timing with the SPOUT unplugged.
The SPOUT can be found on the passenger side firewall near the air filter. It is a square, gray connector that is roughly a half inch square.
How to Adjust your Timing
Unplug the SPOUT connector. Loosen the distributor hold down bolt just enough to allow you to spin the distributor Connect your timing light to the #1 spark plug wire. The #1 cylinder is one at the front of the car on the passenger side. Start your car and shoot the light at the timing indicator on the balancer - it is around 10 o'clock on the balancer if you are looking from the front of the car directly at the engine When you are done timing, tighten the hold down bolt and recheck timing to ensure the distributor did not move while tightening it down. Shut off the car and reconnect the SPOUT connector.
Advancing Timing
The stock base timing is 10 degrees before top dead center.
Most stock cars are able to advance their timing to 14 degrees before top dead center and pickup around 10RWHP.
Cars with aluminum heads are known to like around 18 degrees before top dead center.
When advancing your timing, you increase the chance of pre-ignition (detonation). It is necessary to run premium fuel which is able to withstand pre-ignition much better than lower grade fuel.
Ford 5.0-based engines are dyno proven to perform best at around 32-36* TOTAL timing.
