Mk1 injectors impedance / resistor packs

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Bender Unit
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Mk1 injectors impedance / resistor packs

Post by Bender Unit »

Just a quick one chaps, can anyone tell me what impedance the mk1 injectors are and if the mk1 came with a resistor pack?

Having one last attempt to get this Emanage Blue working on my car and its been mentioned that I need to add 4 resistors as the Emanage as the AE86 injectors are low impedance and the Emanage dosnt like that.

If the Mk1 has some resistor packs then I can source some and see if they make a difference.
sketch
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Re: Mk1 injectors impedance / resistor packs

Post by sketch »

Chris says he'll check the mk1b ones he has when we're back from JAE but he reckons they're 12ohm ....ish :lol:

If you're after a resistor pack we know where you can get one from too :thumleft:
greglebon
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Re: Mk1 injectors impedance / resistor packs

Post by greglebon »

The 4AGE injectors are around 14 ohms: GZE ones are around 3 ohms, and need a resistor pack.

There is no resistor pack for the 4AGE, IIRC..the 14 ohms are regarded as "high" impedence: the GZE as "low".....
pantera2075
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Re: Mk1 injectors impedance / resistor packs

Post by pantera2075 »

Pink standard injectors on the 4age are LOW impedance - approx 3.8 ohms - i've been through all this with my megasquirt - and ended up with a resistor pack from a Rover 216GTi (Honda D16 engined one). Now it works fine.
greglebon
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Re: Mk1 injectors impedance / resistor packs

Post by greglebon »

Hmm....I'm a little confused here...?

I have a set of Black 440's and they are around 3 ohms: low impedance...!

I then remembered measuring a dodgy 4A injector last year sometime and it was around 14 ohms, IIRC..?

So yesterday I looked in a BGB PDF I have which covers the 1988 model, and it says that the 4A are around 14ohm and GZE are around 3 ohms...?

Now this could well be JDM / US market: maybe the UK ones are low impedance..?

It certainly pays to check...? :whistle:
crazybrightman
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Re: Mk1 injectors impedance / resistor packs

Post by crazybrightman »

i cant remember which way around it is but 1a or 1b is low resistance and the oposite for the other model.
then theres the cross over model that looks like a 1b but still have the 1a engine loom and same resistance injectors.
4agte on the way
Bender Unit
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Re: Mk1 injectors impedance / resistor packs

Post by Bender Unit »

Hmm interesting, the reason I ask is because I am having another attempt and trying to get the Emanage Bue working on my AE86 – a chap who has worked with the unit previously has mentioned that it requires a resistor pack to properly drive low impedance injectors.

Hence the question …

I have pink injectors, low impedance injectors on my AE86, and was wondering if there was a Toyota resistor pack that could be used to change the injectors to high impedance – which might make the engine run properly with the emanage plugged in.

Anyone know the result of running a set of low impedance injectors with a high impedance ECU?

Cheers

James
Bender Unit
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Re: Mk1 injectors impedance / resistor packs

Post by Bender Unit »

Can anyone tell me if a stock small port (injectors / ECU) is low or high impedance?

Nathan Freke was running a EMB on a small port without issue ... this might reinforce the resistor claims by the other guy.
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LimeyMk1
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Re: Mk1 injectors impedance / resistor packs

Post by LimeyMk1 »

Bender Unit wrote:Anyone know the result of running a set of low impedance injectors with a high impedance ECU?

Cheers

James


Depends a lot on the ECU but worst case is that it overloads and blows the ECU's injector drivers. :shock:

Are you running sequential or batch fire on the injectors?
greglebon
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Re: Mk1 injectors impedance / resistor packs

Post by greglebon »

Running low impedance injectors when they should be high will probably result in damage to the ECU: the output transistors will overheat / die....!

All the resistor pack does is current limit the circuit.
The injector should run the same as its a PWM on/off signal...?

Any BIG 10 ohm resistors should do to test it , though...?

100W should be fairly safe.. :D One of the yellow ally-clad jobbies.....?

or just use any automotive one...?

Is the ECU not configurable for high or low, like Megasquirt is..?
pantera2075
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Re: Mk1 injectors impedance / resistor packs

Post by pantera2075 »

Just get a multimeter set to ohms and measure across the teminals on an injector.

Low impedance injectors on a high impedance ecu will either burn out the coils in the injectors, or burn out the driver FET's (Or whatever they use in this instance to drive the injectors)

After all, V=I*R

V is constant, so as resistance (Or impedance) goes down, the ampage draw goes up - meaning the drivers (in case of 13ohm against 3ohm injectors) are needing to push 13/3 or 4.3 times the current they were expecting. They won't like it.

Originally I got mine running on 4 off 10ohm 35w ceramic resistors from Maplins - the Rover res pack is more robust and tidier though.
Bender Unit
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Re: Mk1 injectors impedance / resistor packs

Post by Bender Unit »

Depends a lot on the ECU but worst case is that it overloads and blows the ECU's injector drivers.
Are you running sequential or batch fire on the injectors?


The stock ECU is fine and I am currently running the car off that with the Emanage disconnected. The engine has run literally a total of 1 minute with the Emanage connected as the engine was running stupidly rich so I am hoping the Emanage hasn’t xxxx itself in the process – could mismatched impedance cause the injectors to fuel differently before things start to die? The injectors are set for batch fire like the stock set up.

Running low impedance injectors when they should be high will probably result in damage to the ECU: the output transistors will overheat / die....! Is the ECU not configurable for high or low, like Megasquirt is..?


Just to clarify - The car has a stock 4age ECU for low impedance injectors and low impedance injectors fitted. However there is a possibility that the Emanage piggy back needs to work on a high impedance circuit (how true this is I don’t know) The Emanage isn’t switchable and the manuals state nothing about high / low impedance – which I why I think this is a bit of a red herring.

Just get a multimeter set to ohms and measure across the teminals on an injector.
Low impedance injectors on a high impedance ecu will either burn out the coils in the injectors, or burn out the driver FET's (Or whatever they use in this instance to drive the injectors)
After all, V=I*R
V is constant, so as resistance (Or impedance) goes down, the ampage draw goes up - meaning the drivers (in case of 13ohm against 3ohm injectors) are needing to push 13/3 or 4.3 times the current they were expecting. They won't like it.
Originally I got mine running on 4 off 10ohm 35w ceramic resistors from Maplins - the Rover res pack is more robust and tidier though.


This is where is all gets complicated – this is a piggy back ECU so the engine should operate off the factory ECU until I make adjustments, if I need to p1$$ around with resistors then technically this isn’t possible. I would need to source a high impedance ECU and injectoers to stand any chance of pulling it off and then there are issues with wiring etc.

Maybe worth just going to Omex as planned. Just have the unit here and thought I would have another go at getting it going before selling it on.
sebastm
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Re: Mk1 injectors impedance / resistor packs

Post by sebastm »

Hi all,
my MK1a uk-spec has the grey injectors 23250-16010
Just checked, I have 2,2 ohms on my multimeter on each injector, no resistor pack anywhere (engine bay, trunk or behind the battery), and a constant 12v at the injector plug, so have I the wrong injectors ??
jimi
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Re: Mk1 injectors impedance / resistor packs

Post by jimi »

According to the EPC 23250-16010 are for a Corrola AE86.
It lists 23209-16010 (substituted by 23209-16090) for the 1a

edit
1a wiring diagram doesn't show a resistor pack and the spec for the injector resistance is given as 1.5 - 3.0 ohms
sebastm
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Re: Mk1 injectors impedance / resistor packs

Post by sebastm »

Thank you for your reply,
The resistor pack is in the US Haynes manual for the mr2 mk1, and some says on internet only for supercharger models.
I've just bought this mk1a and works very well, but not sure if all is ok with my specs
jimi
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Re: Mk1 injectors impedance / resistor packs

Post by jimi »

The Haynes book of lies is based on US spec models and there are quite a few differences, the wiring diagrams I checked are for the UK spec :wink:
sebastm
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Re: Mk1 injectors impedance / resistor packs

Post by sebastm »

so whatever 23250-16010 or 23209-16010, they are low impedance but with no resistor pack, is it sure ?
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