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Alfs Romeo 2.0 2000 GT - Injector waveforms - Fixed #

Posted by Keith Brown on November 15, 2012, 1:43 pm

Year of Manufacture *: 2008
Engine Size and Code *: 2000
( Optional ) Scanner Used: pico dec3

Hi

Need some help with injector waveform
go easy its my first pico upload!
this alfa misfires intermittently but once rolling runs perfect until ecm comes on
faults retrieved during serial link combustion failure cylinder 1, ignition failure cyl 1
tests so far compression's,smoked manifold
fell into trap of stuffing a coil on
had new plugs,scoped coils all perfect
on scoping number2 injector at the end of event you can see a large "step"as the voltage drops Nos 3 & 4 do the same pic 1

however number 1 doesn't have this step during voltage drop off pic 2, any ideas whats happening at that time
i would normally swap injectors at this point but they are not a quick job

your thoughts ?

Re: alfa GT injector waveforms

Posted by Chris Angus <iframe src='https://members5.boardhost.com/ukautotalk4/info/user=UKAT5111' width='330' height='300' border=0 style='border:none;'> on November 15, 2012, 1:56 pm, in reply to "alfa GT injector waveforms"

If It's what I think you're refering to, it's the mechanical stage of the injector, when it closes, step should be there.
Would be interesting to see the results on ASNU.
Current is slightly higher for that injector too.
Anyway looks like you have a faulty injector.

Chris

Re: alfa GT injector waveforms

Posted by keith brown <iframe src='https://members5.boardhost.com/ukautotalk4/info/user=UKAT1429' width='330' height='300' border=0 style='border:none;'> on November 15, 2012, 2:41 pm, in reply to "Re: alfa GT injector waveforms"
Keith Brown

Thanks for that chris
ASNU?

Re: alfa GT injector waveforms

Posted by Chris Angus <iframe src='https://members5.boardhost.com/ukautotalk4/info/user=UKAT5111' width='330' height='300' border=0 style='border:none;'> on November 15, 2012, 3:12 pm, in reply to "Re: alfa GT injector waveforms"

ASNU,Injector flow bench.

The step in the scope pattern is a good test and indication of mechanical operation and condition and could be just sticking, a good test and proof is to test them on an ASNU bench, you can then see how bad and if a refurb will restore them.
I suspect with the higher current, it's nackered and not fully opening the injector.

Chris

Link: ASNU

Re: alfa GT injector waveforms

Posted by Carl Ford <iframe src='https://members5.boardhost.com/ukautotalk4/info/user=UKAT1822' width='330' height='300' border=0 style='border:none;'> on November 15, 2012, 6:01 pm, in reply to "Re: alfa GT injector waveforms"
Carl Ford

The hump your referring to is called the pintle hump, this shows mechanical movement of the injector.

As Chris has said your injector looks like your issue, I have a good picture and description of a saturated switch waveform from Paul Danners ebook if I remember when I get back on my laptop ill post it so you can take a look.

Regards
Carl

Re: alfa GT injector waveforms

Posted by keith brown <iframe src='https://members5.boardhost.com/ukautotalk4/info/user=UKAT1429' width='330' height='300' border=0 style='border:none;'> on November 16, 2012, 7:07 am, in reply to "Re: alfa GT injector waveforms"
Keith Brown

thanks carl that would be great

Re: alfa GT injector waveforms

Posted by Carl Ford <iframe src='https://members5.boardhost.com/ukautotalk4/info/user=UKAT1822' width='330' height='300' border=0 style='border:none;'> on November 16, 2012, 8:37 am, in reply to "Re: alfa GT injector waveforms"
Carl Ford

Here you go Keith.

Regards
Carl

Fixed #

Posted by Keith Brown on November 21, 2012, 10:01 am, in reply to "Alfs Romeo 2.0 2000 GT - Injector waveforms #"
Message modified by board administrator November 21, 2012, 1:16 pm

New injector fixed issue
thanks chris & carl
looking at the current at start of injection the load is greatly reduced & a much more pronounced closing of the injector ,seen by the step,
new i was on to something ,just needed a push
thanks once again,keith
posted new injector waveform for reference

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