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06-01-2018, 03:29 PM
(This post was last modified: 06-01-2018, 06:09 PM by DeeTurbo.)
Hi,
Just changed my injectors from the 044 to the 076 ones.
I primed the system four or five times. Normally when I've had injectors out this is enough and the car starts normally but this time it took a second attempt to start.
Now, I thought for a quick test to see if the injectors are good I'd unplug the cam sensor, the car shouldn't injector any fuel or sound like it's about to fire and the injectors should hold the pressure that's in the rail.
I should have tested this theory before removing the old injectors.
Tried the above and it does cough a little at first, does this mean the injectors are leaking a bit of fuel into the cylinder and my replacement injectors might be crap and leaking?
What do you guys think?
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Looks like one of my high pressure lines were weeping. Drove the car home and there was a pool of fuel under injector 4. Tightened that up a bit more and I'll see how it starts in the morning.
The injectors are so much better then my old ones, no more injector ticking (it was more dodgy tappets noise) and also there was a dodgy vibration at 2.5k rpm that has hounded me for years now and that's now gone.
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Could the coughing be from crank case oil Vapour? A weep on the line could effect starting as it would reduce overall rail pressure which the ECU would detect.
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Ah, I didn't think of that. It could be I suppose.
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I know of the "leak off" test, but is there a device that can be plugged into the injectors "wire lead" and then plugged into the injector, a "node" ?? which may "flash" when the injector is fired/injecting ??
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My understanding is the injector pulse is 80 volts so you'd need to drop the voltage a lot but that's not what I'm after as when cranking with the cam sensor unplugged there will be no signal from the ecu to the injectors.
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80 volts, maybe one of those "place by cable" non contact type ammeters may work, will give that a try in next few days.
Or, coil placed near wires connected to a DMM ?