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Originally Posted by cre
I would start with swapping the electronic part of the old AFM into the Lex AFM. The electronics are the same and you know the old one works I presume.
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Yes, though the part number is different by one digit and might not be eletroncially identical. I have to supra part in the lexus body now, I will try that swap.
Quote:
Originally Posted by cre
I don't understand your reply about the STA signal. This signal is important as it tells the ECU that the car is being started and despite the airflow being below the specified threshold for the emergency fuel cutoff that it should power the pump and injectors for a set period of time. At least this is my understanding of how it's applied in the 7M-GTE's case. The timing light on the injector wires is to ensure that they are getting a proper signal when cranking. If you know it's getting fuel then this probably doesn't matter.
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Ok, I didn't understand the STA function. I will check it. My only proof that i'm getting fuel is that it almost starts when the injector resistor connector is connected and not otherwise. I believe this takes the injectors on and off line. With my lovely assistant, I will also verify that pressure is over 30psi WHEN cranking.
Quote:
Originally Posted by cre
As I reflect I feel that the explosion may have been either due to the ignition timing being wildly off from the mechanical timing OR the injectors are firing way out of order and fuel is pooling in the runners until that unfortunate spark lights one off. The injectors are low impedance right?
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both issues may have come to play, i think so. those are the two issues I considered: back fire or ignition timing. It sounded more like timing, too loud and crisp for a back fire, not a pop, but a boom. and a lot of protesting cranking, like the engine was kicking back at the starter. That isn't happening any more so I think the timing is at least better.
Quote:
Originally Posted by cre
I wouldn't worry about keeping the other ECU in place. I don't think that's the issue... I could be wrong though.
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I feel the symptoms are different with the new ECU: It definitely is much closer to starting now, chugs in it's own for a second, so I'm thinking the old ecu was damaged by jumping it incorrectly. there was smoke and an ozone smell in the passenger compartment... Just a matter of whether to buy a new M/T ecu. Plan was to wait until I get it running before worrying about that. I will take the old ECU apart and inspect just to see if the board is burned.
Quote:
Originally Posted by cre
I'll go back over this thread in its entirety tomorrow, think about it for a bit and try to see if I can think of anything specific which we've neglected. Have you verified that the injectors are connected in the proper order?
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I really appreciate your help. the injector plugs are long enough now that they could be connected out of order, but it would be pretty obvious. Only #5 and #6 are easy to mix up. I will verify continuity to the correct injector resistor pins per TEWD with a voltmeter. Also will verify that both leads to 1 and 4, 2 and 6, and 3 and 5 are in continuity with each other. Connection of each of the 3 circuits to the ECU was already verified with voltmeter yesterday.
FWIW - I wonder if air/fuel mixture could be way too rich. I have AFPR, A/F adjust screw on the AFM, and a bosch 'BOV' (recirculating discharge with stock plumbing). I have checked for boost leaks carefully, so I don't think that is a problem, but I might have been fixing boost leaks when the problem starting first occurred, before I screwed up the timing. Just another factor to consider.
Thanks again.