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EA82T #1 & #2 Injectors staying on??

Posted: Tue Aug 11, 2009 8:29 pm
by RSR 555
Can someone help with this small issue with my Daugther's RX Sedan. I went to start it today and was having troubles with it cranking over. I went through the usual elimination stuff and found that both #1 & #2 Injectors are staying powered constantly?? I just woundering if anyone else has had this problems?

Posted: Tue Aug 11, 2009 8:33 pm
by Gannon
When the ignition is on, all 4 injectors have 12v on one side. The ECU then grounds the injectors to fire them.

Are you testing them with the ignition on?

If you are, i would suggest that maybe 2 have no power. Check the resistor on the drivers side strut tower.

I dont have a wiring diagram, but id be checking the supply to the injectors

Posted: Tue Aug 11, 2009 9:35 pm
by steptoe
and I thought these were batch fire , as in 1 & 3 together, 2 and 4 together.

Posted: Tue Aug 11, 2009 10:01 pm
by RSR 555
sorry, I should have mentioned that there is 12v power to all injectors but what is happening is... with the ignition on but engine not running, both #1 & #2 has a closed circuit (meaning both injectors are energized) and allowing fuel to run constantly. The fuel stops after the initial priming cycle is complete (about 3sec). I can only run the engine with both #1 & #2 plugs disconnected, as soon as I have the engine running and try and put the plugs back on, the engine bogs down and stalls after about 20secs. :confused:

Posted: Tue Aug 11, 2009 10:03 pm
by RSR 555
steptoe wrote:and I thought these were batch fire , as in 1 & 3 together, 2 and 4 together.
yeah.. I believe they are but I'm under the impression both 1&2 are together and 3&4 are together.. but I could be wrong.

Posted: Wed Aug 12, 2009 1:07 am
by El_Freddo
They would be batch fire - and I think the way they do it is to pair two injectors that are spaced as far apart in the cycle as possible - so 1 and 2, 3 and 4 would be paired I'd imagine.

If that's the case, I'd be checking for a grounded wire in the loom somewhere in the engine bay, probabily near a bit of body work - like where all the wiring pokes out from. Also check the explosed wiring that is not covered with any protective condute/tape.

Otherwise I'm all outta ideas - I've been away from EFI's for too long now :( Can't wait to get back "in the game"

Cheers

Bennie

Posted: Wed Aug 12, 2009 2:23 pm
by steptoe
was thinking same - earth. rewire from ecu to injector may be the easy fix - if it not ecu itself

Posted: Wed Aug 12, 2009 4:09 pm
by Gannon
They are not batch fire as there is no CAS (crank angle sensor). They all simultaniously fire, but are driven in pairs in case one of the drivers in the ECU fails.

Posted: Wed Aug 12, 2009 5:37 pm
by RSR 555
Cheers everyone.. I'm going out now to check out the wiring.. I have got myself a wiring diagram and lets hope it matches. I found on the diagram that all 4 injector (trigger) wires go back to the ECU and the 2 in question are about to be shown who's boss!

Posted: Wed Aug 12, 2009 6:16 pm
by RSR 555
OK.. well I think we found the trouble.. Thanks Jay for helping me with the wiring but it appears to be fine :)

When I pulled the ECU plugs out, I thought that they looked a little corroded :confused: so out came the unit.. few screws later and have a look...

Image

Posted: Wed Aug 12, 2009 6:25 pm
by AndrewT
is it a 3plug or 4plug?
If it's 3plug I have a spare ECU for you.

Posted: Wed Aug 12, 2009 6:29 pm
by Gannon
Is that the output resistor that fried?
Got any more detailed pictures?

Posted: Wed Aug 12, 2009 6:48 pm
by Porty
Looks like a voltage regulator or somethin... Be carefull but, the ecu itself may not hav caused this, it could have been a short circuit in the external wiring..

Posted: Wed Aug 12, 2009 7:00 pm
by AndrewT
Porty wrote: it could have been a short circuit in the external wiring..
RSR 555 wrote: When I pulled the ECU plugs out, I thought that they looked a little corroded
most likely... :)

Posted: Wed Aug 12, 2009 7:32 pm
by RSR 555
AndrewT wrote:is it a 3plug or 4plug?
If it's 3plug I have a spare ECU for you.
Thanks Andrew, it is a 3 plug version, looks like I better come and see you and I can look at the other stuff while I'm there :) I believe the reason it fried was due to a leaky front screen. Suba (Mike) is coming to fix for me tomorrow. Cars!!

Posted: Wed Aug 12, 2009 7:34 pm
by RSR 555
Suparoo wrote:Is that the output resistor that fried?
Got any more detailed pictures?
Just snapped this one with my phone but I can take a bunch with a real camera if you like? anything in particular you wanting to see?

Posted: Wed Aug 12, 2009 7:45 pm
by Gannon
just what it is and where abouts its located on the board

See if it can be fixed, before too long these things will be even rarer than they are now

Posted: Wed Aug 12, 2009 10:47 pm
by steptoe
why i am a bit shaky about mine, used to get a small amount of moisture before I got it and some parts got a bit of the green verdigris about it. have also seen after market ecu in Brumby in what looks like a sandwich bag ! All four firing at once is probably right given the era of the first EA82T 1985, back when Cordia turbo was throttle body injection, Ford had MPFI and still lots of carbies and even three years later Ford offered throttle body injection on the EA Falcon and TB really only replaced a carby so delivering a continuos spray of fuel, just subie mpfi was closer to the need!

Posted: Thu Aug 13, 2009 6:16 pm
by RSR 555
Suparoo wrote:just what it is and where abouts its located on the board

See if it can be fixed, before too long these things will be even rarer than they are now
Yeah.. fixing it as a spare or for someone else that might need it later, sounds cool with me.. do you know anyone that repairs them?

Here's some more pics...
Image
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Image

Posted: Wed Sep 21, 2011 12:15 am
by jaymoor
Hey did you manage to fix your ea82t ecu, i bought off one ea82t to restore and in the process discovered the previous owner had messed the ecu. i one of the 3 transistors is missing T607(green in colour). the previous owner told me that the fuel pump failed and the techs told him its the ecu. would you help me with the part no for that green transistor so i could fix this ecu. thanks:)