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wagondragon

87 FI subi wont start / intermittent spaz sessions

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So i recently bought an 87 subi wagon, it had intermittent spaz sessions where it would lurch from low rpm to high. it happened under load most. I think tracked it down to the FI system, most likely electrical... i thought i fixed it with a new rotor and cap as it ran well for about a mile... when it completely stopped getting fuel. My fuel pump is fine. but I tested the FI itself and it its impedance is out of spec. I'm not sure if that can cause it to fail to inject fuel or not, but currently my next move is to get a pick and pull fuel injector that passes the ohms spec from the book. ive got all the pieces of the puzzle except fuel to get her started again.

 

Any of you guys think that the spaz sessions, and the not starting is the same issue? Is there anything i haven't thought of that could be causing this issue? If so which systems would be good to check? Thanks in advance.

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have you looked for any codes on ECU. I know some say no codes will show unlss ecu light is on, not suree if that is Sube specific as my S1 EA82T mpfi had an error in it without ecs light on, fixed error problem, on my way. I think these S2 EA82 mpfi - it is mpfi ?? not spfi ?? had a doo dad near coil, but not part of coil bracket, that has a ceramic outer and provides some sort of electrical need for the injectors on turbo side strut tower on RHD

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Yes, fuel filter is good. tested the psi on either end of the filter 20 psi all the way. The fuel stops at the injector, for some reason it is not firing or it is plugged up. And yes i checked the codes, it says the fuel injector is not firing. ( its exact words are a little different... but thats the jist of it. ) Its SPFI, non turbo. There is a kind of fuse box over there, but i cant think of anything else, maybe thats what your talking about jono? Does that provide electrical to the FI system?

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Swapped the FI with a pick and pull, also the Throttle Position Sensor, started when i first installed, but after about 5 seconds it shut off. Now its not spraying fuel anymore. ECU is still sending the code that says the FI is bad. Or atleast that its not injecting fuel, for whatever reason. So i think im down to bad ECU, or bad electrical someplace in the system...

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oh STOP it, you will be giving Tweety the horrors ! He had a rather nasty experience with spfi conversion, now it is hello Weber !

 

OK, disclaimer is I know nuttink about spfi, just got the inlet manifold and its throttle body ,,

 

the electrical resistance thingy about the mpfi of 87 onwards, do not think is for spfi at all. It looks to be inside a white ceramic just like resistor housing material on a points resistor

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Yeah... i put a weber on my 85, runs great. But i bought the 87 for its 5 speed and some of its electrical parts for 350$ off craigslist... couldn't pass it up. :) Mainly trying to get everything running to make sure it all works before donating it to my 85.

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i have found that the desired pressure could not be checkd for unless the fuel gauge is T'ed into the fuel pressure line not just as  an end of the wall measure. 35 psi seems to be about the normal mpfi running pressure T'ed in

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I was looking through the troubleshooting section and it mentioned a resistor that doesn't appear to be in mine... If i can track one down thats my next best guess.

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Well, im pretty sure the resistor is for newer models. So thats out... I'm going to try the ECU next. I tested all the wires and sensors that i can think of that are connected with the FI system and they all seem fine. The only thing that was bad is that the FI was not getting volts from the ECU when i tried to turn it over. Unless there is some other system that can stop the ECU from sending to the Injector, like a fail safe. I'm assuming its the ECU.

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it would help yourself and others if you volunteered what info you have on the ECU model number, and as it seems you found other model numbers - list them too . The info won't hurt sitting in the archives.

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Ill have to get those when i go back next time. I guess i was mainly wondering how much difference they had between models. If that was knowledge someone had...

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So does anyone know what years they used the same ECU? i went to a wrecking yard and the model numbers were different than my 87... Help!

 

Only 87 SPI ECUs are compatible according to the parts book.

22611 AA200 and 201

I`d pick a 201,if I had a choice,but,I would check the wiring between the injector and the ECU plug first.

Edited by naru

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Thanks for the feed back... now to just find an 87 near me... I also checked the wiring from the ECU to the FI and its going through just fine. Just not getting the message to fire when plugged in.

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Fixed! It was the ECU all along... damn dirty thing... thankfully there was ONE 87 in my area that was FI. Started right up when i swapped it out. Next to check if all the components i want to swap over to my 85 are good. Thanks for the feedback fellas!

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