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Weird electrical problem G4 thunder


Skylinekrille

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Running a V8 twin turbo using Thunder ECU along with a Ron francis blackbox.

Using 1 relay for each coil pack bank, and 1 relay for the injectors. These relays are triggered by the ignition switch along with the G4 thunder Ecu, and also a Dash2pro.

Whats happening is if i turn on the ignition switch everything fires up, if i then turn off the switch, there are some kind of +12v "back power" that keeps the ignition ON, and the injectors starts to click and i have to pull the main switch to kill everything, this is when the Ecu is plugged in, if i unplugg the Ecu its fine, and i get 12v att all injectors etc and i can turn the Ignition off. And i am not cranking at all also.

in PC link everything looks fine from all sensors and all, ive runned several earth feeds both to the chassi and also the engine.

Ive measured on the 12v ignition feed to the injectors and for some reason i get some kind of power from the injectors, not 12v, but around 8-9V and pulsing when the ignition switch is off. This small voltage tho holds the relay ON for some reason. I tried to unplugg everything and only connect 1 injector but same problem, of course only the injectors plugged in is clicking then.

So im kind of out of ideas at the moment

 

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Weird. A friend of mine emailed me a day or two ago with a simlar, of not the same, problem where AFTER cranking it one of the banks (v6) coils were getting hot and there was clicking noises also. He said it came from the coils, but could also be injectors. I dont know yet. Hel also had to yank the ecu out of its sockets or pull the main power of it to stop the issue... Hmmm :/

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Note it's a holiday here in NZ today so link support won't reply today. 

Most likely it is some device wired to one of the aux outputs that is back feeding - are they all wired per the pclink help?  You could try pulling all aux out pins out of the ecu connector to confirm that

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With ECU on check the runtime values for all the individual Battery voltages. On my thunder when wiring it I stuffed up the ECU hold wiring. Wouldn't get full battery voltage and ECU would still have slight power when ignition switched off.

 

If u post ur file I can test it on mine 

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Ive tried to disable and also unplugg everything connected to the aux, only using a few at the moment for lile 2 boost solenoids, its a pure drift car so not many gadgets.

I can check the runtime values later, not at the car right now. I know if the ignition switch is On i have like 12-13 volt shown in pc link, if I turn of the switch so the injectors starts to click, it shows like 8 volt, only checked this quick cause I don't want the injectors to freak out

Thinking if it's possible to use the Link main relay control output to the relays feeding the injectors and coils, if this would fix my problem?

Or is it cause the Ron francis blackbox is messing things up?  It has programmable relays that can either switch to +12v feed, or gnd, tho if you program a relay to switch to +12v, that output is grounded when Off. And if you program it to switch to Gnd, it has +12v when off.

Edited by Skylinekrille
Added some ideas
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If you still have the same problem with all aux's disconected (f/pump, fans, boost solenoid etc) then it must be something else odd with your injector or ignition supply.  I suggest you post a schematic of how you have wired the main supply relay and associated connections to ecu, inj & ign.  Even just scribble on paper and post a photo. That will make it quicker & easier for tech support to work out the problem.

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wiring.gif

 

Made a quick diagram, not sure made it right tho. just of the injector part and the boost solenoids, hence i have diconnected the solenoids now. Didnt bother to put out the fuses, but i have the ECU wired threw a fuse, And i am not running the ECU threw the relay box at the moment, cause if i manage to start as its acting at the moment i wont be able to shut it off since i want the ECU to be connected to the kill switches 2nd feed apart from the alternator current. 

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I tried using a separate relay to just feed the ECU, but got the same problem, thinking if just making a relay board with 1 big main relay controlling smaller ones thats feeding injectors, etc. I use some relays on the Blackbox for controlling lights, steering, fuel pumps (disconnected atm) and so on,

Most runtime values seems fine, only thing i can notice is weird is that Aux 11, 12, 14 and 15 shows "Open circuit" but they are not even wired into the connector. And are shut off under AUX settings

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The schematic above is not complete enough to say with certainty but from what you have shown I would expect it to work ok provided the "blackbox" is programmed correctly and it behaves like a mechanical relay (i.e its outputs do truly go open circuit when off and its inputs aren't even weakly tied together or to anything else (pull ups etc)).  It seems like the black box it is a fairly new product so there may be some odd bugs/behaviour that is not documented...

You havent shown the coils/ignition system in that schematic - how is this connected?

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The coils are LS1 style with 4 pins, and in using 1 relay to feed 4 coil packs each from the black box, also 1 relay is programmed to switch to gnd to control the fuel pumps, and 1 gnd, 1 signal GND, and then its the 8 wires from the Ecu, again these are disconnected due to troubleshooting.

The full system when connected consists in 3 temp sensors, water, oil and intake air. 1 tps, 1 map sensor, 2 MAC boost solenoids, 1 crank trigger and 1 cam trigger, cam triggers are getting 8v feed, and map and tps 5v feed. 2 pressure sensors for oil and fuel Wired to AN volt inputs. 

Injector test and ignition test were all OK. Haven't tried in a few days but the engine runs fine if i crank it up and start.

 

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does the ECU power down when you disconnect power from the blackbox?  I'd think the blackbox is backfeeding 12V to the ECU, keeping it powered up

 

I think JMP could be on the money here. For the backfeeding to occur there will be a battery supply keeping the ECU from completely shutting down. Looking at the diagram you post it appears the blackbox is the only device (excluding ign switch and main switch) that receives batter +ve. For a test why don't you change the battery +ve supply to the black box to be ignition switched.

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I can try that. It feels like everything probably shuts down if I do that. Since the kill switch kills the power to the blackbox. Will try it later today, if this is the problem i guess the relays inside the blackbox are to sensitive and holds the circuit ON even at low voltage maybe.

Also gonna get som standard relays and just run it without the blackbox. 

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Tried some different wiring now, it seems like i can't use the blackbox for engine control.

So ill just make it simple and use standard relays wiring, have used up to much time with this annoying problem now. I could use a big relay to the blackbox main feed i guess but it will render it completely useless since I also wanna controll fans, waterpp, lights and wipers with it without having the ignition switch On.

In curious in that case if i should use the Main relay control function built into the Thunder ecu, or just go with standard main relays and sub relays controlled by ignition trigger?  Or is this function mainly for use with Ecu hold power function?

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