1UZ swap ignition circuit help
05-11-16, 01:12 PM
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1UZ swap ignition circuit help
Hey guys, I'm working on a friends car and I have completely run out of ideas. I just can't figure this out for the life of me, and I'm requesting your help.
We are doing a 1UZ swap into his S13, using S13 5 speed trans with 1UZ ECU and engine harness. Donor car was a 1991 LS400, running and driving when we took the engine out. Harness was uncut. Obviously some wires and plugs that weren't necessary were removed. Took off all the EGR stuff, no more clutch fan, no trans harness, no sub O2s. But i am fairly confident nothing I removed will keep this from running.
Now, my issue is I am getting no spark at all, from either coil. To test if im getting spark, I have pulled the coil wire off the distributors and I am watching for them to arc. Yes, I have power at the main circuit. Yes, the igniters are grounded. Yes, injectors fire. Yes, the ECU is on (CEL works, doesn't register any codes). Yes, the coils and igniters are good/working and all have power. I simulated IGT signal from the ECU to the igniters by giving IGT1 and IGT2 wires power, and each respective coil fired. So everything from the igniters onward works. So, it would seem, the ECU is not sending IGT signal. My first step was to check the crank sensor. It ohmed out a little low, so I replaced it. New one was within spec. Both cam sensors ohmed out good, however I've read they they aren't responsible for the ignition per say, but I checked anyways. I checked continuity for both crank sensor wires through the plug for the crank sensor to the ECU plug (in case of a wire loose from the plug or broken wire). Both wires had continuity. The shared ground for the crank sensor and both cam sensors also is good. I then checked continuity for both IGT wires the same way. Same deal, both had continuity. Then, I figured, it had to be the ECU. Figured the capacitors were leaking. Got a new one online, and today, it gave me the same exact problem.
I'm sure I left something out. I've been working on this damned thing since November. If you can help in any way, please do, before I push this thing into a ****ing lake.
We are doing a 1UZ swap into his S13, using S13 5 speed trans with 1UZ ECU and engine harness. Donor car was a 1991 LS400, running and driving when we took the engine out. Harness was uncut. Obviously some wires and plugs that weren't necessary were removed. Took off all the EGR stuff, no more clutch fan, no trans harness, no sub O2s. But i am fairly confident nothing I removed will keep this from running.
Now, my issue is I am getting no spark at all, from either coil. To test if im getting spark, I have pulled the coil wire off the distributors and I am watching for them to arc. Yes, I have power at the main circuit. Yes, the igniters are grounded. Yes, injectors fire. Yes, the ECU is on (CEL works, doesn't register any codes). Yes, the coils and igniters are good/working and all have power. I simulated IGT signal from the ECU to the igniters by giving IGT1 and IGT2 wires power, and each respective coil fired. So everything from the igniters onward works. So, it would seem, the ECU is not sending IGT signal. My first step was to check the crank sensor. It ohmed out a little low, so I replaced it. New one was within spec. Both cam sensors ohmed out good, however I've read they they aren't responsible for the ignition per say, but I checked anyways. I checked continuity for both crank sensor wires through the plug for the crank sensor to the ECU plug (in case of a wire loose from the plug or broken wire). Both wires had continuity. The shared ground for the crank sensor and both cam sensors also is good. I then checked continuity for both IGT wires the same way. Same deal, both had continuity. Then, I figured, it had to be the ECU. Figured the capacitors were leaking. Got a new one online, and today, it gave me the same exact problem.
I'm sure I left something out. I've been working on this damned thing since November. If you can help in any way, please do, before I push this thing into a ****ing lake.
05-12-16, 01:26 PM
#3
just to state the obvious, have you check all the fuses? what concerns me a bit is the removal of the trans harness. the trans control is built into the ECU and if, for instance the ECU thinks the car isn't in park or neutral, it will not engage the starter. i am uncertain if spark is also inhibited during that scenario, as well as that IGT signal you mentioned.
05-12-16, 02:27 PM
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just to state the obvious, have you check all the fuses? what concerns me a bit is the removal of the trans harness. the trans control is built into the ECU and if, for instance the ECU thinks the car isn't in park or neutral, it will not engage the starter. i am uncertain if spark is also inhibited during that scenario, as well as that IGT signal you mentioned.
As for checking fuses, yes I have checked fuses. I am not using the Lexus fuse box, just using enough wires to run the ECU and harness.
05-12-16, 08:49 PM
#5
Unless someone has figured out how to use the LS400 ecu, personally I would go with an aftermarket controller. And since it would have good install instructions as well as programmability its just worth the extra cost.
I think these guys could better answer your questions.
http://www.lextreme.com/forums/index.php
I think these guys could better answer your questions.
http://www.lextreme.com/forums/index.php
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