davepak

As a means of a test @john in KY could I connect a wire from injectorr #3 to #4 (The ECU signal) to test whether both injectors would work then? This considering both fire at the same time? Im guessing if this would work, it will tell me that indeed there is a wiring/splicing issue from the ECU to the injector harnesses and it is not reaching cylinder #4. Alternatively, could I attach a wire all the way from the ECU to the injector harness to try to get the same result? Once again, to test if there is a broken path from the ECU to the injector harness? . But here is the very odd thing!! Injector harness #3 had 12v on the battery pin side and 0v on the ECU side, however when measured together, these pins read 12v! On the other side, on injector harness #4 I had 12v from the battery pin side and 12v From the ECU side, which is what I expected, as the ECU would actuate the injector by sending a ground pulse. HOWEVER, I can start the car with injector #3 attached and I must disconnect injector #4. Is the ECU going nuts? But another note is this: the car does not really have any custom wirings or odd splicings. I have found most of the connectors and harnesses in mint condition as close they were from the factoy. Just to be clear: The issue is on injector for CYL#4 that needs to be disconnected otherwise the car would not start: FAN /Front of Engine //////--+--/////// CYL 2 CYL 1 ** CYL 4 CYL3 -------------------------------------------- Windshield /Passenger Cabin

I have the FSM and I've been reviewing all I can think through them @idosubaru.

I thought about that, but the car had a recent over haul. I t wasnt driven much, as I live abroad and come back once or twice a year to **try to** use it.

Thanks @idosubaru that combination swith was tricky but it worked. **Update** I am totally mystified with the XT, beginning to think it is haunted or possessed or something.. So I changed the ECU to a known working one, I replaced 3 seemingly faulty injectors as they would leak as soon as the fuel pump would prime and during starting. Here is the thing, the car would not start, and by chance, I unplugged the connectors to injectors 1 and 2 and the car started awfully. I reconnected them, crank but no start. I then removed injector connector #3 and the car started, on 3 cyclinders. It even got some idle. Checking all connectors, I found harness #3 had the following: 12v on the battery source and 0v on the ECU pin. Ha! I said to myself, here we've got something. I checked continuity on that ECU pin source and it seemed fine up until the engine harness. So I attached a test harness providing the known 12v battery source and a "bridge" all the way to the ECU. No effect. Here I admit there might be an issue, maybe im testing the wrong pin. However, on the test it didnt start. Here is more: on reconnecting things, I then realized that it is now cylinder #4 the one NOT cooperating!? so I reattached harness for #3 and disconnected harness #4 ....and... the car started ! Running on 3 cylinders and maintaining some "steady" idle.. So the car would not start on 4 cylinders. No fuses or fusible links blown. No relay failures, ECU works, there is spark, there is fuel and fuel pump action, rotor, cables and sparks are ok. But the cylinder pair #3 and #4 have something going on. Where the ECU only "allows" one cylinder to work. As I said this is really mystifying It seems as if the problem "shifts" from one injector harness to the other. That would fit a fairy tale, but not a machine with (+) positive and (-) negative. Question: Is the ECU and the MPFI one and the same inside the same enclosure? Or is there an MPFI controller somewhere tucked under the blower motor that needs to be checked up? Shouting out for help, whether someone has faced such a strange thing

This is the headlight switch section that was faulty, I soldered a piece of wire to actually allow connectivity between the two needed points for the actual operation of the High/Low beam. The orange arrows point at the exact section where the conductivity was lost hindering the operation of the High /Low beam. @idosubaru The second plan of action was just that, to attach a pair of soldered wires and place a push button somewhere to actuate those lights. In fact, a few years ago I placed an entire custom wiring with a fuse and a relay to operate the high/low beams with a switch totally separate since I couldn't fix the combination switch then. This repair was a home run! As now all the original wirings are in place and the switch works to a 90%

**UPDATE** I've fixed the control wing's headlight combination switch by bridging a faulty connection with a tinned copper wire and removing the push button function of the High Beam, leaving a pull and push action instead. ECU: The new ECU arrived and after hooking it up the car wouldn't start. I traced a problem on 2 injectors. After removing the harness for injectors 1 and 2, the car started although roughly as running on 2 cylinders. I got 2 injectors and fixed the issue only to find now injector #3 flooding and not working! As I disconnected #3 & #4, the car started immediately but again on 2 cylinders! This Soobie is a treat! I'll get another injector tomorrow and hopefully it'll fire up once and for all!

Next new problem.. The control wing with the headlight switches So I found the switches and push-buttons aren't working well.. If anybody has any idea if this can be fixed..

I'm waiting for the new ECU, the alternator is next in line for troubleshooting. I've also repaired the combination headlight switch. The high beam push button wasn't working.

My dad told me he realized that he noticed the negative terminal of the battery loose ( I was abroad at that time) so that is one possible suspect of the electricity issues. He was tracing back those possible issues while I was away. He told me as well that he could not test the alternator since the car didn't start, this means as you mentioned that the alternator needs to be rule out for faults. Once the ECU arrives, after checking wirings, I'd attempt to start the car with the alternator disconnected and test the outputs from it, whether overcharging or any other potential fault. I know the effects of a bad thermosensor on the engine's performance. It wreaks havoc as the ECU receives wrong info on the engine's temperature. Also the PCV, EGR, O2 sensor among others. Oh I had both front CV joints clicking, I actually repacked them with grease but.. they were really bad, loose as marbles , I put new joints, boots, bearings, they look mint now ! Thanks as always for the tips and advice! davepak

Hey @idosubaruyou're right, I'm going to run some tests on the alternator and check the wirings. Last night I checked the wiring diagrams from the manual to follow the power sources and potential threats to the ECU. The alternator is one of those. On another thought, I wonder if the knock/detonation sensor might have had something to do with your car in the past. As it's a part of the turbo system. I can say that the car actually ran better after the engine rebuilt and removing the turbo. But it wasn't for long, the sputtering started and I thought typically fuel pump issues. But now I've got better info to check for the culprit. Then again, maybe the ECU just gave up. Or as mentioned before, maybe the injector harness.. On the axles.. Yes, they're solid. I managed to put a boot on the LHS one before it lost the grease so they're safe. Three days ago I installed new outer CV joints from German quality and OEM specs. Can't wait to try it on the road!

Thanks gents for the info and inputs! Well, it was originally an EA82T but when I got the car the turbo was broken beyond repair. I had the engine rebuilt and used the regular pistons, therefore making it a regular EA82 naturally aspirated. This car has been really abused and badly maintained. I've tried to take it to its best possible shape.. My worry about the ECU not working was based on a possible error should the ECU didn't "see a turbo input" but reviewing the posts.. I understood this shouldn't be a problem. The ECU will read the air flow from the MAF and act accordingly. I suspect a wiring issue with the starter motor or the ignition circuit which could have fried the ECU, although the car had been suffering from hesitation and sputtering consistent with a faulty ECU, perhaps showing end of life service signs. This, because I managed to fail-proof peripherals like spark, distribution, fuel pump, thermosensor and a plethora of other possible suspects. So.. Either a short somewhere fried the ECU or the ECU failed (moist maybe, or age).. The updates will continue! The new ECU it's on its way, meanwhile I'm washing all the seats, servicing the rear calipers and shock absorbers Dave

I agree with you @1 Lucky Texan, first call of action was to try and repair it. But it doesn't look good. The only question now is whether I have to modify a pin in the upcoming ECU to "cancel" the Turbo signal /pulse? I'm guessing the ECU doesn't "read" the turbo or does it?

Thanks @idosubaru! What I have done is sourced the exact same ECU which is on its way, probably a week to get to me. In the mean time I'm working on peripheral jobs like brakes, upholstery, radiator fans, shock absorbers etc. This car is now a non turbo regular EA82 with a MPFI system. I guess I'll have fingers crossed when plugging in the new ECU. As I wonder if the ECU will be "wondering" where the Turbo is. The actual picture does not show much of the damage, as I thought of a repair by myself.. But on the other side of the circuit board it looked pretty bad, you can see the pictures.. I'll update soon!

Hi guys, I've recently discovered my XT's ECU was fried inside, I took it apart and saw the burnt electronics. For a long time, it had a lot of sputtering and hesitation. My suspicion is that it developed a short circuit. When trying to start it, it would blow the fusible link, I traced all I could until hesitantly checked the ECU, it looked bad inside with signs that a massive short circuit took place. But I can't avoid wonder if something else could have had a short which burnt the ECU.. Top left corner is all burnt. (On the image) Question, do I need to replace the ECU with the exact same type as it originally came with? Are there any issues regarding whether it is Automatic or manual transmission, turbo or non turbo?. I have a real unicorn here, it's a 1986 XT 3AT converted to a non turbo with non turbo pistons... Any thoughts, as always very much appreciated! davepak

Hi there Subaru lovers! I have an old XT 1987 and it is giving me grief! I have just installed knock sensor and thermal sensor, but I found a leak on the distributor, I changed the O-ring, disassembled the whole thing and it still leaks, I saw it's not from the O ring but maybe from some the little holes on the distributor's body ? Has any body had this issue before? Help please! Dave