BMG

Just been testing my injectors as I got a "open circuit" error on injector 1 the other day. Number 1 reads 13ohms while the other three all read 13.2 Ohms. Is the 0.2ohms difference within tolerance? I'm struggling to find tolerance limit info anywhere.

They all "sound" the same when I listen to them tapping away and I have checked the wiring etc with a multimeter and a light and all connections are good.

This car seems to come up with new errors all the time....I have a feeling the PCM might be on the blink!

Rick

That's fine.

For Open circuit you would need a much much higher reading. More likely a wiring issue.

BMG

I checked the wiring harness (checking continuity with multi meter)yesterday - from injectors to the first multi plug. I couldn't find any shorts (and or cross wire talking) or lack of continuity between the wires and the pins. All injectors share a common 12v pin on the plug and the wire must splice off to all 4 injectors. All of 12v pins on each injector had continuity with each other (makes sense as they all splice off the same wire) and when I plugged in an injector (say number 4) all of the 12v connections on each injector had continuity with the ground/switching wire pin for injector 4. I assume this is as expected as when you plug connector for number 4 it completes a circuit with the injector and as all 4 injectors share a common 12v they should be able to talk to the switching pin for injector 4. When I plugged in 3 and 4 the 12v for injector 1 and 2 could talk to switching pin for 3 and 4 and so if i plugged in injector 2.

If it is a wiring issue it must be between the plug and the ECU which is a ballache to sort out. The haynes manual "forgot" to add in the injector wiring in the manual for the duratec engine, which is annoying as I don't even know what PINs on the ECU connector to test.

Might try and replace the injector to see if it makes a difference. Interesting though that I have got two errors - I have got the P0201 error and then after that was cleared I got P0200 - which is the circuit in general, which makes me lean towards wiring issue!!

Rick

You can swap the injectors round to see if the fault moves.

GVK.

Injectors are common on KA duratec, sister had one go on her Sport Ka

As Rick says swap round to see if code changes.

stevieturbo

You need little to test wiring.

Test between each injector plug and battery ground. Ignition turned on, unplug all injectors and test. 1 pin of each plug should be full battery power or damn close to it.
the other pin at the ecu will almost always read very close to battery power, but slightly less. As long as it reads this that proves the circuit is connected to the ecu and the ecu is live.

Or test with a scope or similar to see if you're getting a proper signal when cranking. Some people will say use noid lights....IMO they can be a mixed bag and sometimes misleading.

But moving injector from one cyl to another is an easy test, ( wiring stays at its own cylinder of course )

stevieturbo

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