Explosion, now no start.

[cre]

Ok, I didn't notice you had mentioned the smoke and burnt electrical smell previously... Wow, did I actually miss that? Check wiring too, more may have burned than than the ECU. The ECU is pretty well closed up, actual smoke is more likely to present from wiring or a relay. Do you know that you jumped the wrong pins? If so which ones? One big issue with burning wire harnesses is that the wire doesn't always burn to the point that continuity is interrupted, you often get shorts across other wires where the bundle is wrapped tightly together... not fun to track unless you can narrow it down by locating two devices which are not both operating and share the same harness.

No need to buy another M/T ECU, the A/T ECU should function the same. I'm pretty sure there aren't even any wiring changes to be made.

The fuel mixture would have to be obscenely rich to prevent the engine from at least chugging for a minute after a cold start. Especially if it's been allowed to sit long enough for the excess fuel to evacuate. I'm talking rich to the point that the injectors are leaking. Now, that said, it might behoove you to pull them and test them as specified in the ECU to be sure they're not leaking and are opening when voltage is applied. The shock of the combustion in the intake could damage injectors but I don't think it's very likely. If you think the cylinders are flooded then pull the plugs, crank the engine for several seconds and let it rest for 24 hours to ensure that the vapor has had time to evacuate the cylinders.

The electrical components in the two AFMs are identical and present the same scaling when tested in the same housing. They are completely interchangeable. The housing swap generally requires tuning. I do not recommend using the air bypass screw for this purpose. Its scope is full spectrum and the airflow signal needs to be tuned selectively for the best performance and to ensure that you're not creating any lean spots or washing a cylinder. Do yourself a big favor and invest in a fuel controller and a wideband controller. The wideband is an invaluable diagnostic tool. Innovate Motorsports makes a couple very inexpensive controllers that are very well rated and easy to use.

A boost leak isn't going to cause a problem like this... You'd have to have a 1" or larger hole in the piping to see something this bad. A leaking BOV won't have any affect on the operation of the engine when not boosting.

You haven't made any modifications to the AFM or sprayed any type of cleaner on the sensor, have you?

I haven't gone back through the thread yet and it's been a long day. I will try to make time tomorrow. Hopefully we can get this sorted out in the next couple days and have you on your way. Open and inspect the old ECU as you said. If any of the traces or components are burnt see if you can identify which pin(s) on the harness are related and thus limit the amount of time you may need to spend diagnosing the wire harness.

[vikenabm]

checked wiring - I pulled the dome fuse because there was a question of a minor short in that circuit. Otherwise, no short to ground. and so far haven't found any wiring faults doing voltmeter tests on the ECU. Here's what I did: jumpered the car with positive to positive and negative of the other car to the positive alternator output. Don't ask me why, in do know better. blew a fusible link and a a fuse, replaced these and had headlights coming on but not popping up, and not turning off with the headlight switch off. When I finished testing all the circuits for shorts and replaced fuses the lights worked normally and it was behaving pretty much normally, minus the dome light fuse, except the ECU, which I replaced. Now seems okay except the starting issue. Really no idea why the lights went haywire or how they resolved.

Not flooded - tried it several days, same result. Also, I usually disconnect injectors or injector resistor and then crank with throttle open to clear a flooded engine and that isn't helping with this problem.

I have a wideband
Fuel controller is the next purchase. once it starts.

No mods to the AFB and no cleaner on the sensor.

Don't sweat the time frame. I'm a weekend warrior mostly, but your rosey prognostication gives me hope, thanks. Couldn't work tonight, it's day by day.

[cre]

I've been through this with a couple MKIIIs and I know a few others who've been there too. It's a royal pain and typically is due to more than one point of failure or something which the ECU and the TSRM don't know how to diagnose (such as a short in the wire harness across two lines such as Vc and Ks.... been there, rebuilt the whole harness). With diligence you'll find it it just takes patience and a lot of deep breaths.

Now that you have an ECU that you're more confident in in place you should check for error codes regularly to see if it sees something we haven't.

[vikenabm]

Okay, I think I've covered all your questions so far.

I verified fuel pressure, set it to 35. Only issues is that may AFPR leaks pressure a little too fast when the ignition is off. I don't think that is keeping it from running.

My injectors are correctly wired to both the ECU on one side and the injector resistor on the other side. THe injector resistor has a good ground.

My ignitor works, it is wired to the correct coil packs and plugs, and the plugs all fire in pairs as described in my write up on the first page of this thread. I hope what I write up is the correct wiring for the 7MGTE - it was the best I could figure from available sources.

I pulled all my plugs - one had a cracked ceramic insulator, don't know if it was firing. others were intact but ALL PLUGS WERE both WET with gas and black with soot, and there was a thin layer of gas on each piston.

My intake air pipes were sooty from sporadic intake runner ignitions.

My original ECU still doesn't run the car, though it cranks. It had no evident burned circuit board components when i took it apart. The new ECU still almost starts the car, it chugs along very rough for a second or two.

I swapped the electronics on the AFM. I'm using the one that came with the Lexus throttle body.

Any thoughts now?

[vikenabm]

I just remembered i might have put in the rc 660 injectors when it stopped working. Would that be enough to flood it?

[vikenabm]

I just remembered i might have put in the rc 660 injectors when it stopped working. Would that be enough to flood it?

[cre]

I'm probably not going to be here much for the next couple days. My grandfather went into the hospital and was diagnosed with a hematoma (sp?) in the brain. It's nothing they can correct and he was on blood thinners so it's just a matter of time.

Would you please set your crank to 0?BTDC, take the cover off of the CPS and post a picture of the internals? I'd like to see if it's clocked correctly internally.

The 660's would make for rough running and starting but it should still burn and not fire back into the intake plenum. I'm not saying it's not possible but I don't think it's very likely. Have you inspected the ISCV and the check valve to make sure enough air is entering the manifold when the throttle is closed?

[vikenabm]

I'm terribly sorry for your grandfather. I'm a medical doctor and know exactly what you are saying. I'll post here as a sketch pad in your absence in case anyone with a similar problem stumbles on the thread. Between the cam timing and trying the stock injectors I think I will have my answer. thanks.

[vikenabm]

It's running! A handful of problems, but the primary issue was mixed up wiring from the CPS. I found two reversed wires before, as posted, fixed those, but didn't notice the other two were also reversed. fixed nose and it started, running on two cylinders.

Then I was able to sort out the wiring from the ignitor to the coil pack. the wiring from the harness to coilpacks 2 and 3 were reversed in trying to check the wires last week.

This was further aggravated by 650 injectors with the lexus AFM mod. I think I will need a piggyback ECU to make that run well, so I went back to stack injectors and AFM for the winter to get the bugs out. I believe you were right though, the lack of starting was not primarily from too much fuel, but I don't think it helped.

But the original problem leading it to sound like the valve timing was off, and causing detonation, backfiring, etc, was the CPS wiring. Mystery solved.

I will recheck my ignition wiring post to make sure it matches what worked.

THANKS for your help. Hope things went as well as possible with your family issue.

[cre]

Finally! Excellent! I'm just bummed it took so long to sort out. I really need to take pictures of the CPS harness on the next pre89 and 89+ that I end up working on.

With the injectors and the Lexus AFM you should be fine if you pull 10% off the mainscale whether it be with an adjustable fuel pressure regulator or a fuel controller. I would wait until I had a fuel controller though as you're still going to want to fine tune the rest of the fuel map.

Everything with the family was as I expected. He passed on quietly after a couple days, most of us understood what was going on and had no issue but there are a couple family members who are going to need time.

Congratulations on getting it back together! I do hope you'll keep us posted on your progress... As with many things you see a lot more horror stories and than success stories on forums.