Any update for you? I am having problems too, albeit at the relay pulling 1.85amps with the key off, causing an excessive power drain killing battery in hours. I just managed to get my ECU out to search for repair/ replacement.

 

I'm sorry to say that I have no update nor, regrettably, do I have any advice about how you might proceed. As you can see from my prior postings, I have done seemingly everything that one might conceivably do. And yet, no luck.

Either the clean bill of health given for my ECU is incorrect (always a possibility) or there's something, somewhere, in the wiring that my regular mechanic (who is reasonably accomplished with electrical issues) could not identify.

As mentioned previously, I have now put my car in storage for the winter, so I will not be contending with this aggravating problem until the spring.

I'm hoping to find some sort of automotive electrical genius in the Portland, Oregon area. Of course, if anyone knows of such a genius, I'd sure be grateful to hear about it!

 

If you have your original ECU, you might “get another opinion” …. I like SIA since this is their core business and trust the process and repair approach and the transparent reporting provided on what they find.

https://siaelec.com

 

Thanks. I am aware of SIA. Since the car is now in storage until the spring, further checking of my original ECU will have to wait.

By the way, in case anyone has had their ECU worked on previously and, for whatever reason, needs to have it repaired or even examined again, be sure to check with the repair operator that they will accept a previously worked-on ECU.

I had sent my previously worked-on ECU to one such (reputable) repair service only to be told after they had received it that they would not service an ECU that had been previously repaired by someone else. I was more than a little peeved about this because there was no such disclaimer on their Web site. It cost me 10 valuable days without my car + the cost of shipping—all to accomplish absolutely nothing.

 

Hi All,

When I last left this matter in October, I had put the car in storage for the winter. Finally, in mid-March, I took one last stab at what had become an aggravating problem. The solution to the problem came in the form of Auto Electric Specialties in Portland, Oregon. The owner, Terry, is one of those modest geniuses who solved the problem.

We left the car with him for two days. Finally, he calls and says, "Really, I dunno. I don't doubt that there is a problem. Because when I took apart the EFI (electronic fuel ignition) relay that you said had burned out and the car wouldn't run, I discovered that the relay was not burned out at all. Yet when I put it back in, the car wouldn't start."

He submitted that the car probably had an "intermittent short". Which he couldn't definitively locate.

"About 40% of the wiring is hidden and can't easily be seen. But," he added, "there are two wires leading to one of the oxygen sensors [the car has three of them] and I switched the wires, making one of them the new ground and the other connected to the power. That might, just might, if we're lucky, be the source of the problem."

He further added that he ran the car at 2,000 rpm for 90 minutes and could find no electrical malfunctions. "But that's not real-world driving at different speeds with road vibrations."

So he gave us a little jumper cable connected to a 20-amp fuse, the wire ends of which which could be inserted into the sockets where the EFI relay goes.

"There's a 30-amp fuse on the EFI relay circuit. So when you're driving, if there's a short, it'll instead blow that 20-amp fuse easily. And then we'll know for sure." (He gave us two additional 20-amp fuses so that we could limp back home from our test drive.)

So we drove to the Coast with our little jumper installed in place of the EFI relay. 200 miles round trip. No problems at all. Car ran perfectly. No check engine lights appeared.

We removed the little jumper device and installed a new (OEM Denso) EFI relay and drove for eleven hours to California. No problems. Car runs like it always did.

Bottom line: It wasn’t anything to do with the ECU. And whether it had anything to do with the igniter (replaced); the fuel pump (replaced); the distributor (replaced); or the ignition coil (replaced), I'll never know.

Terry at Auto Electric Specialties modestly says he got “lucky”. Maybe. But talent creates its own “luck”. I'm grateful to him and certainly recommend him to anyone in the Portland, Oregon area who has an auto electrical problem.

By the way, you might be interested to learn that, because the car is registered in California,[size=33px] [/size]I took the Lexus for emissions testing so that I could renew the registration. Passed easily, as follows:


HC (ppm)--Maximum allowed: 82 Measured: 30

CO (%)-- Maximum allowed: 0.48 Measured: 0.08

NO (ppm)-- Maximum allowed: 687 Measured: 66


Not bad for a 30-year old car with 257,000 miles on it. So there you have it. The Lexus lives.

 

Wonderful news - sometimes some good help is worth its weight in gold. Glad to hear you're cruising and enjoying that bad boy!

 

Wow! Lucky indeed! I am happy for you that the problem seems to have resolved itself somehow.

Your recent saga and logical testing with your mechanic has given me food for thought for my own SC which I suspect has been suffering from a very similar intermittent compromised wiring issue which is extremely hard to diagnose. Like you I have also determined that it's not down to a bad ECU... since I have four identical ones to test with.

Thank you for sharing your experience with us and I do hope that this is the last you'll ever see of this problem

 

Rudy/Kahn,

Thank you both for your very kind messages. Much appreciated.

Matteo