Do G40's suffer from this?
As soon as full throttle is applied (WOT), the ECU should switch immediately to the map fuel value and bypass the lambda. However, this is where the Digi-Lag problem occurs since instead of going to a steady fuelling range, the ECU continues to cycle the mixture for a unfixed time period (usually between 1-3 seconds). This can be seen by the continued spiking of the yellow A/F plot even though the RPM's are approaching 6k from a downshift by the tester. Notice the boost is climbing to 15psi and the engine is still going into very lean conditions!
Digi-Lag is the lag in Fuel Enrichment under Full Throttle.
After the ECU finally hits correct enrichment, it only stays there until you change gear and floor it again. As soon as WOT is released, the whole process starts again. So you get Digi-Lag over and over through the gears!!
I had/still have this exact problem i read a load of digifant training manuals from the 90s and 80s and understood some of it. because my co pot was screwed really far in (too temporarily mask another problem) so the ECU cut it off and thought it was faulty. because of this the ecu didnt enrich fuel during the on off for gear changes making it really jerky. since then ive solved the problem meaning i can set my co pot properly. and it made a massive difference!! can really tell the difference from not enriching to enriching. (wrote all this in my build thread)
however it does still do it very slightly, a little bit of jerkiness. can probably live with it. how would you eliminate it completely?
Quote from: z3i on September 15, 2013, 07:35:08 PM
I had/still have this exact problem i read a load of digifant training manuals from the 90s and 80s and understood some of it. because my co pot was screwed really far in (too temporarily mask another problem) so the ECU cut it off and thought it was faulty. because of this the ecu didnt enrich fuel during the on off for gear changes making it really jerky. since then ive solved the problem meaning i can set my co pot properly. and it made a massive difference!! can really tell the difference from not enriching to enriching. (wrote all this in my build thread)
however it does still do it very slightly, a little bit of jerkiness. can probably live with it. how would you eliminate it completely?
Sorry for the off topic but, do you have any documents about Digifant ecu?
Ill try dig them out, i need to go to the library to photocopy them and upload to the forum as my scanner is fudged
Ok mate, thanks a lot for any help