M
Mustangcwo
Guest
EEC IV: How to Steady/Set that Idle
Wednesday, 24 September 2008
When modifying your 5.0 you have to allow the EEC IV computer to reestablish settings and train itself to keep your vehicle’s idle steady and within specification.
Changing any components that deal with air flow, exhaust, fuel pressures or ignition can throw off the engine idle and create surging. MustangCWO used these steps after changing to a cold air induction and increasing fuel injectors to 30lbs and Mass Air to 75MM on his 1987 GT. Just follow the steps below and WALAAAHHHH, you’re idle will become steady as a rock.
Note: Engine Codes and Vacuum leaks that could be upsetting the car must be resolved FIRST.
SETTING IDLE:
Set the idle speed by using the following sequence:
1. Clean TB with carb cleaner and nylon brush (a toothbrush works great). Engine off, fully open TB blade and spray/brush TB until all gunk and oil residue is cleaned.
2. Allow to dry, or close TB blade and start engine until it clears all carb cleaner fumes/liquid.
3. Let engine idle, if it doesn't, increase idle speed via TB stop screw until engine stays idling on its own. Continue to let idle until it engine is warm(or until computer switches to Closed loop mode at around 140-150 Deg. on the ECT(Engine Coolant Temp.)).
4. Disconnect IAC valve, if engine dies repeat step 3 with IAC disconnected.
5. Turn the throttle plate hard stop screw counter-clockwise until the lowest factory idle speed setting of 625 rpm is obtained. It may be necessary to increase the idle speed if the engine has been modified.
6. Turn the engine off and reconnect the idle speed control solenoid.
CHECKING THE TPS VOLTAGE:
1. Turn the ignition switch to the on position, but do not start the engine.
2. Using a digital volt/ohm meter, measure the voltage between the Dark Green/Light Green wire and the Black wire (may have to strip a small area to insert voltage meter probes). The voltage should read between 0.8 and 1.0 volts.
3. The TPS voltage can be adjusted by loosening the two screws and slightly rotating the throttle position sensor. If necessary, elongate the mounting holes on the TPS to obtain this reading.
FINAL COMPUTER ADJUSTMENTS
1. Disconnect battery (-) for 3-4 minutes. Reconnect battery, start engine, allow it to idle for 2-4 minutes to confirm setup. During this time, all accessories are to remain in the off position.
2. If idle speed falls too low or stalls, increase idle speed via the TB set screw a little at a time.
3. Turn engine off for 20 seconds, re-start engine and repeat step 8-9 if stalling occurs.
4. Turn engine off for 20 seconds, re-start and turn all accessories on. Allow it to idle for 2-4 minutes to confirm setup. If engine stalls, repeat steps 8 through 11.
5. Reconfirm TPS output is within the .7vdc - 1.0vdc range... you are done!
Now get that car out of the garage and back on the road. It’s time to check out the new mods!!!
Wednesday, 24 September 2008
When modifying your 5.0 you have to allow the EEC IV computer to reestablish settings and train itself to keep your vehicle’s idle steady and within specification.
Changing any components that deal with air flow, exhaust, fuel pressures or ignition can throw off the engine idle and create surging. MustangCWO used these steps after changing to a cold air induction and increasing fuel injectors to 30lbs and Mass Air to 75MM on his 1987 GT. Just follow the steps below and WALAAAHHHH, you’re idle will become steady as a rock.
Note: Engine Codes and Vacuum leaks that could be upsetting the car must be resolved FIRST.
SETTING IDLE:
Set the idle speed by using the following sequence:
1. Clean TB with carb cleaner and nylon brush (a toothbrush works great). Engine off, fully open TB blade and spray/brush TB until all gunk and oil residue is cleaned.
2. Allow to dry, or close TB blade and start engine until it clears all carb cleaner fumes/liquid.
3. Let engine idle, if it doesn't, increase idle speed via TB stop screw until engine stays idling on its own. Continue to let idle until it engine is warm(or until computer switches to Closed loop mode at around 140-150 Deg. on the ECT(Engine Coolant Temp.)).
4. Disconnect IAC valve, if engine dies repeat step 3 with IAC disconnected.
5. Turn the throttle plate hard stop screw counter-clockwise until the lowest factory idle speed setting of 625 rpm is obtained. It may be necessary to increase the idle speed if the engine has been modified.
6. Turn the engine off and reconnect the idle speed control solenoid.
CHECKING THE TPS VOLTAGE:
1. Turn the ignition switch to the on position, but do not start the engine.
2. Using a digital volt/ohm meter, measure the voltage between the Dark Green/Light Green wire and the Black wire (may have to strip a small area to insert voltage meter probes). The voltage should read between 0.8 and 1.0 volts.
3. The TPS voltage can be adjusted by loosening the two screws and slightly rotating the throttle position sensor. If necessary, elongate the mounting holes on the TPS to obtain this reading.
FINAL COMPUTER ADJUSTMENTS
1. Disconnect battery (-) for 3-4 minutes. Reconnect battery, start engine, allow it to idle for 2-4 minutes to confirm setup. During this time, all accessories are to remain in the off position.
2. If idle speed falls too low or stalls, increase idle speed via the TB set screw a little at a time.
3. Turn engine off for 20 seconds, re-start engine and repeat step 8-9 if stalling occurs.
4. Turn engine off for 20 seconds, re-start and turn all accessories on. Allow it to idle for 2-4 minutes to confirm setup. If engine stalls, repeat steps 8 through 11.
5. Reconfirm TPS output is within the .7vdc - 1.0vdc range... you are done!
Now get that car out of the garage and back on the road. It’s time to check out the new mods!!!