MicroSquirt.com read only forum (Jan.15,2018)

ok! it is making more sense now!!

i got a new vb921 (after i blew the last one) and got my engine started for the first time this evening, had to change the req fuel alot to get it going!

it is idling very rough, so i need to make a fair amount of adjustments/checks but i will be resetting the req-fuel as discussed, many thanks philip for your replies!!

best regards

scott

Like most newby's, I've been using 1ms as my injector opening time in the absence of accurate data on my injectors.
 
This morning I measured the injector opening time with my oscilloscope.  For a laugh (and possibly stern corrections...) I'll share HOW I did this.
 
I tried both methods of changing the number of squirts and the other method of using the EGO cross-over point but neither worked for me.  So I decided to do it the way I prefer anyway - measure with test equipment if possible.
 
I used the inductive pickup from a broken timing light and put this over one of the wires going to the injector.  I certainly did not see the waveform one would get with purpose made test equipment but I could clearly see a dip at 1.3ms where surely the pintle must hammer home in the open position and a dramatic rise where the injector closes.  Programming this in has, subjectively, improved things.
 
It seems to me that there are three parameters one must have REALLY close to correct - IF you want your msq file to be repeatable :
1) injector flow rate (which implies req_fuel) - this one I'm still guessing...
2) injector opening time 
3) base timing.
 
Kind regards
Philip
MS-2/V3/2.35/MT 2.25/Innovate LC-1/LSU4.2
Land Rover 4.6 std, 4-2-1 exhaust headers, IAC
'80 Jaguar XJS V12 5.3 (10:1 CR) is waiting for its turn

 

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