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injector
24vseven - 25/10/07 at 08:49 AM

hi folks is there any way i can check if an injector is fireing ie check for electric pulse without fancy equipment i dont have
cheers


matt_claydon - 25/10/07 at 09:11 AM

At idle they fire slowly enough that you'd see it flashing if you connect an LED (with drop resistor) across the injector.

A 12v test light would also work but you won't see the flashing.


twybrow - 25/10/07 at 10:50 AM

Fantastic. i needed to know that too. My bike engine wont start and I have no idea where to begin looking... How about for the coils? Can you test for a feed to the coils?


BenB - 25/10/07 at 10:59 AM

For the coil why not just test the spark plug (ie plug a spare spark plug into the HT lead and hold it (with insulated pliers) against the engine block whilst turning it over. You'll see it sparking if the coil's okay.... If you're not getting a spark then putting a suitably resistored LED (or 12v LED) across the coil input will show if the coil is getting a signal.

If you're testing the spark plug against the block it's best to do this with a spare plug. Otherwise (unless you take out the fuel pump relay and empty the float chambers) you'll have unburtn petrol vapour pumping out of the de-spark-plugged cylinder head with risk of fire...


britishtrident - 25/10/07 at 11:14 AM

Proper name for the LED test lamp for injectors is a NOID lamp --- I have no idea why ?

I have a full set very handy -- cost me less than a tenner.
http://www.toolsnstuff.co.uk/product_info.php?products_id=11561

You can also use a LED alternator tester probe and ressitor for the same job

[Edited on 25/10/07 by britishtrident]

[Edited on 25/10/07 by britishtrident]


twybrow - 25/10/07 at 11:45 AM

Thanks guys. I am scared somewhat of doing the classsic spark trip, after jumping about 2m when I got a shock from my trackday 205 gti trying the same trick! Once bitten and all that.. But it sounds like the way forward tonight.


westcost1 - 25/10/07 at 12:14 PM

Not shore about bike engines but the injections on my xr2i lump can be herd firing a (small tap) and if you put a finger on them it can be felt to. Disconnection them and squirting a bit of fuel round the garage works well to. Check the fuel pump has enough pressure to open any fuel regulators that’s why my engine didn’t start first time. And don’t hold the plug or lead as it will give you a belt one of those things you do once lol rest it against the exhorts manifold or something to ground it.

[Edited on 25/10/07 by westcost1]