effect of using low impedance injectors without resistor's

[beatle]

Can anyone tell me what would happen if i used low impedance injectors without a resistor pack on a standard ECU?

the reason i ask is because i did.
the car only ran on 2 cylinders, just tested the injectors (3s 430cc type) and only 2 clicked (ran them off the battery).
i tried putting the standard injectors back in and now it just overfuels to the point it hydro locks after a few cranks (in all cylinders)
pulled out the standard ones and they all click.

what have i fried?
unfortunately while trying to sus out why it was only running on 2 i ran the only spare ECU i have access to, so if it has damaged mine, it has probably damaged my mates too

fnny thing is though, when i first put the standard injectors back in it ran, now it wont?

[oldcorollas]

high impedance injectors will pull roughly 1amp each
low impedance injectors will pull roughly 4-5amps each

4-5 amps through your injector drivers (transistors) is probably not good.

[beatle]

hmmm, seems like i am a little bit screwed then

[JZA70R_92]

if you lived closed by could of wacked your ecu into my jizza but mine manual though............................................ .................................................. .................................................. .........

[beatle]

now i spose my next question will be where i can get 3 ECU's repaired in perth at a decent price

[wilbo666]

As said the excess current has probably damaged the transistors. The injector drivers are screwed to the alloy heatsink that sticks up on the lower left of the ECU...

If you measure between pins 2 and 3 on the transistors with a multimeter and it is connected then the transistor is damaged (Measure with the the positive multimeter lead [red] on pin 2 due to the inbult diode...)


The JZZ30 ECU that I have here has 2SD2162 Transistors in it (3 of them).

http://www.necel.com/nesdis/image/D14865EJ2V0DS00.pdf


Jaycar is prbly the easiest place for you to get some replacements from... TIP122 is what they have and they are pretty close... I've give them a go, and suspect they will work fine.

http://www.jaycar.com.au/productView.asp?ID=ZT2292

NOTE: You'll need to isolate the rear of these transistors from these from the alloy heat sink however (TIP122 isn't in an isolated package like the stock transistors).

Use these (Or similar) http://www.jaycar.com.au/productView.asp?ID=HP1160


Cheers
Wilbo

[beatle]

you sir are a madman, i cannot thankyou enough

[thechuckster]

now i spose my next question will be where i can get 3 ECU's repaired in perth at a decent price

sorry - but did you manage to burn 3 ECU's ?

[beatle]

burnt 2(my one a my mates spare) in testing, one was already deaded from leaking capacitors(my spare)

[DrNick]

Seriously man, if i burned out an ECU I would be troubleshooting the problem before plugging in another one. Ah well, hopefully it will all be sorted soon

[JZA70R_92]

I would put back in stock injectors and repalce all the blown caps not that hard if your handy with a soldering iron and cheap to!

[thechuckster]

it will have blown the injector drivers (FETs i think) and possibly other current-limited hardware attached to the injector driver circuit. Without specs on the silicon parts in the ECU (and Toyota does use some funky hardware in their ECUs) i think rebuilting a zorched ECU would be an uphill battle.

[beatle]

Seriously man, if i burned out an ECU I would be troubleshooting the problem before plugging in another one. Ah well, hopefully it will all be sorted soon

didnt realise the injectors were the wrong impedence till i took them out.
i was told they were exactly the same a 2jz ones, only 430cc not 440cc, the reason i got them is i swapped them +cash for a set of blitz 540cc because of the impedance of the blitz ones and not wanting to fuck around with resistors...

ECU was previously spitting code 14, which is:
3 or 14
IGNITION SIGNAL
NO "IGF" SIGNAL TO ECU
IGNITER/IGNITER CIRCUIT
IGNITER AND IGNITION COIL/CIRCUIT
ECU

so i tested all the wires in the ignition system, were all good
so tried different igniter and ECU
still wouldnt work
but was defintely getting spark now.

so pulled out the injectors and put in my standard ones, ran on 5 cylinders (#1 injecftor wasnt plugged in due to bent pin on injector) this was about 11pm, shut it down, went to bed happy.
next day nothing, cold fish, injectors not clicking except everynow and then 1 would click hard and the whole thing would be flooded very quickly

upon closer inspection of the ECU (thanks to WTF for the help) my mates ECU has blown capacitors which have leaked out onto the board but neiter ECU show massive signs of failure from the FET drivers.
though it does smell of fish?

[thechuckster]

...neiter ECU show massive signs of failure from the FET drivers.
though it does smell of fish?

The FETs have probably lost their saved electrical smoke and have changed from Feild-Effect Transistors to Fish Effect sTench objects.

[DrNick]

didnt realise the injectors were the wrong impedence till i took them out.
i was told they were exactly the same a 2jz ones, only 430cc not 440cc, the reason i got them is i swapped them +cash for a set of blitz 540cc because of the impedance of the blitz ones and not wanting to fuck around with resistors...

ah thats terrible luck buddy.
lemme know if you need to make up a resistor pack i can give you some details on what i used.