E48 lowest safe injector resistance (4cyl)

[ignitionautosport]

You will have 12V at both injector terminals if they aren't firing. It is one of those things which catches you out unfortunately if you don't know what to look for. You would need to ground the injector at the ECU side then measure current and voltages through the circuit.

I suspect ECU holds high (12V) when off to help slam the injector closed and collapse the field in the coil quickly, but can't confirm over the net

[miker33]

As a side note having contacted Allan at DTA the E48 is capable of driving the 3 ohm Evo injectors with the 6ohm ballast resistors in series with each injector (or a single large 1.5ohm on the live feed shared to all injectors) but he recommended going up to 10ohm per injector (or 2.5ohm shared).

[stevieturbo]

You will have 12V at both injector terminals if they aren't firing. It is one of those things which catches you out unfortunately if you don't know what to look for. You would need to ground the injector at the ECU side then measure current and voltages through the circuit.

I suspect ECU holds high (12V) when off to help slam the injector closed and collapse the field in the coil quickly, but can't confirm over the net

But with the injector unplugged, and resistor box unplugged, there was still 12v at the normal 12v terminal ?

Weirder still....with a noid light fitted in each injector plug ( with resistor box plugged in ) it wouldnt flash on any cylinder ! yet the car would run fine on 3 cylinders.

Anyways, I'll agree that wiring in series does make more sense. That Evo was weird full stop.

[richie webb]

It isnt totally clear. But the white wire is 12v and passes through to the rear of the 4 resistors and connected to all.
The other wires are tapped off the injector trigger wire pass through each resistor and sink to the 12v at the opposite end.



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The weirdest thing about this method. If you measure resistance at the injector itself, to the ecu pin, you would simply think it is wired directly as happened only a few weeks ago when I came across a car where a single injector was not operating.
Wiring appeared intact with virtually zero ohms between injector and ecu. But without the resistor in place the injector simply will not operate. One of the resistors in the pack had went open circuit.

Can you tell me what cars you can get these resistor packs on,I need 2 of them for projects I am doing

cheers Richie

[ignitionautosport]

Can you tell me what cars you can get these resistor packs on,I need 2 of them for projects I am doing

cheers Richie

A lot of Mitsubishi, including but not limited Libero, lancer, etc.

[stevieturbo]

The one above was an Evo 8. ( middle of bulkhead ) I assume most Evo's use similar ?

Defo a 1990 Honda Civic CRX, so perhaps more Hondas ( left side strut tower )

And Toyota MR2 turboss, I assume GT4 etc as well. No idea about the n/a cars.

[richie webb]

Thanks I will take a look in the scrapyards

cheers richie

[Uno4ever]

Hi guys!
I would like to ask if i am going to face any issues in case i use ballast resistors (correctly wired i suppose!) with a set of four 2.5 Ohm Siemens-Deka fuel injectors, on my DTA-S40 Pro ecu.
Thanks in advance for your time,
Costas

[stevieturbo]

If wired as per instructions then you should be fine. But yes if the injectors are 2.5ohm you must use resistors or a driver box.