Engine Tuning - Discovery 1 V8 i - 3.9

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Cassim

Guest
How do I adjust the air fuel ratio on my disco. Where is the adjustment screw located.

Also, I had my coil replaced, distributor cap, rotor , ignition module and injectors replaced. Now I hear a constant clicking from the top of the coil. Sounds like it's losing fire.

Please help!
 
B

byronAU

Guest
Cassim said:
How do I adjust the air fuel ratio on my disco. Where is the adjustment screw located.

Also, I had my coil replaced, distributor cap, rotor , ignition module and injectors replaced. Now I hear a constant clicking from the top of the coil. Sounds like it's losing fire.

Please help!
The fuel/air ratio of your engine is completely controlled by the ECU [14 CUX type] and you can't effectively alter it.......its part of the hard/core programming of the ECU, its values derived from various sensors and changing constantly all the time.

Sorry , but YOU can't do it except maybe with a whole lot of specialised equipement including a twin roller dynomometer or a rolling road and the permanent installation of a more sophisticated [expanded memory] "piggy back" ECU.......it ain't just a screw adjustment that you can set "by ear"!
 
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A/F ratio is controlled by the ECU responding to signals from the oxygen sensors.

The easiest way to control it is to switch to mega-squirt EMS and then, you can program your fuel map as you wish via your PC. There are other ECUs that are user-programmable, but none are plug-n-play.

There are a coupla companies producing replacement proms that allow for a fixed fuel map substitution.

PT
 
Oct 27, 2004
3,000
4
Actually, A/F CAN be leaned/riched with a screw on your MAF. However, that is something if done wrong can go really bad.