Injector opening time changed !!

[Philip Lochner]

I was recently tidying up some of my wiring primarily to clear massive interference noise on the car audio system (since traced to being caused by the Lc-1s).

When finished, started the Jag and was very disappointed to find AFRs becoming so rich as it warmed up it would die!!

The short version of what I found (or so I think) is this: The injector opening time had reduced from 1.3ms to 1.15ms compliments of improved electrical connections.

I had a "chocolate block" connecting 12V and the flyback leads from MS2 to the wires feeding the injectors with 12V which I had now replaced with pre-insulated crimp lugs. It would seem that this modification resulted in sufficient improvements in electrical integrity such that the injectors now opened quicker causing way too much fuel to be supplied once warmed up.

It is quite possible that due to the fact that I'm running 3/simultaneous (which results in PWs fractionally more than than the injector opening time at idle with 0 load), the effect of the changed opening time is much more pronounced.

Its a good thing perhaps as can you imagine how difficult it would have been to find the cause of this symptom if I was using say 2/alt which would have much greater PWs at idle and would have resulted in the AFRs being slightly more rich but not enough to prompt a search for the cause!! Chances are I would retuned the VE table forever wondering why that was necessary if the car had been fine and stable for months before that.

Although highly frustrated by this - MS has taught me, yet again, a very valuable lesson!!

[quattrodave]

Hiya Philip,

Fair point and it is certainly worth baring in mind, i have also found a dirty/corroded fuse/fuseholder will cause a similar problem!!!

The injector opening time had reduced from 1.3ms to 1.15ms compliments of improved electrical connections

The only thing i was a little supprised at was you reduced the inj opening time to 1.15ms, i've found that i am unable to adjust the inj opening time to more that one decimal place ie: 0.9ms is fine however 0.95 gets changed to 1ms?!

Is this a change in a recent code release or something??

many thanks

Dave

[Philip Lochner]

, i've found that i am unable to adjust the inj opening time to more that one decimal place ie: 0.9ms is fine however 0.95 gets changed to 1ms?!

MS-2/Extra R2 allows you set the opening time to 3 (THREE) decimal places, independantly for inj_1 and inj_2 !!!!

[Vicoor]

By changing the resistance, and therefore the current through the injector you really affect the closing time more than the opening time. I posted some waveforms on a previous thread.

viewtopic.php?f=29&t=29912