Efi Adjustment

[Guest Fred2b]

I know the EFI engine is controlled by the computer box of goodies but the airvane has an air adustment screw underneath which can be turned with an allen key. Now this engine is 1989 vintage and I am sure it has been moved many times, in fact let me hold my hands up..... I took it right out, to see how it works you understand.

The question is how do I adjust it to be correct? At the moment it is about 1.5 turns out but that does not seem to make any difference to the running where ever it is. In fact it will still run if I take it right out.

Is there a baseline setting for this screw and what exactly does it do?

 

Regards

Fred

[Guest DaveB]

Hi Fred

 

I have sent you a message with three files which should tell you all you need know to set up the EFI system and fault find.

 

Good Luck

 

Dave B

[Guest Ant]

Not sure if this tallies with the documents, but my understanding is that this is rather like turning the idle jet of a carb, only it restricts the air flow rather than the fuel flow.

 

At idle there isn't enough air flow to open the flap on the air flow meter, hence the second small passage which is permanently open. At high load conditions this delivers an insignificant amount of air when compared to that flowing through the flap. At idle it delivers just the right amount of air to match the fuel delivered by the injectors.

 

So, the way to set it up is to connect an exhaust analyser and look at the Lambda value. With the engine fully warm and idling adjust the screw to get a lambda value of one.

 

To some extent you can do this by ear - listening for a smooth engine note and 800rpm, but an exhaust analyser is usually available at any friendly MOT garage, so it's best to do it then.

 

Ant