Did you ever figure out what killed the piston?
Did you ever figure out what killed the piston?
Not for sure...it was some kind of detonation. Probably a combination of lean-ish spots on the map and the near-overheat incident.
Just got back from break-in driving. I ended up moving ReqFuel up to 13.4 because I thought I heard a little pinging, but it could just be wrecked engine PTSD I seem to have now. I definitely heard a little pinging on tip-in when driving next to a jersey barrier, turning the wall-wetting from "Off" to "EAE" seemed to fix that. Also semi-sequential fuel injection mode works well.
Haha I knew that was too easy. Car refused to start this morning. Tried old tunes, nothing. Looks like the crank sensor's bad. I look at changing the crank sensor and see that coolant is leaking out and the front engine mount is badly torn. This car's not going on track tomorrow.
Edit: Maybe the problems are related. The coolant leak is around the back of the water pump, right above where the crank sensor is. It's epoxy-sealed but the wiring may be twist-n'-taped.
Confirmed, I drained the coolant into a bottle not long after I saw the leak, a couple of hours later the engine started right up. The dripping soaked the wire overnight, causing a glitchy crank sensor signal which prevented it from starting this morning. Took it to get the leak taken care of. Looks like I'll have to do the autocross with my blind DIY tune, if at all.
Well the problem was a dying crank sensor. I found this out after working on the car until after midnight on Saturday and the car giving hell to start on Sunday morning. I knew the wire was dry and was now confident that I had the most perplexing automotive problem in history on my hands, a car that fails to start due to crank signal errors but then runs fine all day long. The car refused to start just as I was set to leave, but on the final hail-mary attempt involving a gravity push start, it fired up. Great, I thought, I'll just never shut down until I get back home after the event.
But about half way to the track, I heard a buzzing noise at engine speed, and within a few seconds the engine shut down. Crank sensor error. Zero tach movement. Now this makes sense, at last. It's a bad crank sensor.
So I rolled the car backwards a loooong way down the hill and parked it to be towed later. Took my mom's BMW 116i to the autocross to try to salvage some points, but I was still bringing a knife to a nuclear bomb fight.
Towed the car to the electrician in the evening. The crank sensor had made contact with the trigger wheel enough that it milled through the plastic and then the sensor itself. The engine fired right up with the spare sensor I had. I also got the WBO2 system wired up while I was there.
So this week I'm going to get the engine mounts taken care of and then on the weekend, maybe get the O2 sensor itself installed (it won't screw in where the factory sensor was) and definitely get something done with that crank sensor mount to prevent this from happening again. It's set a generous distance from the wheel right now to preserve it, but this causes more frequent sync loss problems.
Got the front and gearbox-side engine mounts filled with glued-in solid urethane pucks, tomorrow morning I'm going to get the wideband sensor installed and maybe a trafficator repair done if there's time, and the in the afternoon I'll get the crank sensor modified and maybe do a little tuning.
OK so time to recap the weekend.
Saturday morning I went out and found that the only place that does exhaust work on a weekend here is the guy who welded up the exhaust leaks I blew open on the track back in December. So I got him to put the O2 sensor on. Unfortunately a blob of weld spatter got in the way of the sensor, and not realizing this he used the wrench a bit too early when putting it on and damaged the first thread on the sensor. So it wasn't a straightforward job...but it was on.
A friend took it for a quick test drive and told me that it was working well but I should raise the limiter. I thought that was odd, the limiter's at a rather generous 8200RPM when the engine is warm. Anyway, didn't think much of it.
Next I went to the electrician to get the crank sensor modified and maybe do some tuning.
I haven't seen what they did to the crank sensor yet, but sync loss is completely eliminated now, even over the bumpiest roads. We went to do some tuning and on the first pull up to redline (first time I'd run it over 6500rpm myself), I seemed to hit a limiter at 7krpm. Did another run, same thing. The electrician said the engine was running lean at high RPM even after he set it to run massively richer after the first run. We tried creeping up to high revs in case it was fuel starvation, since the tank was low, no difference. So it either has a failing pump or a plugged filter. The car's going in to have that looked at tonight, I got a new pump, and a new filter just in case.
It is quite possible they put the dumbed-down fuel pump on the SR5 economy model. I had no trouble with the stock GTS fuel pump and the 20V at 7K RPM. But on the RAV4, the fuel pump is way smaller, so Toyota doesn't just use a generic fuel pump, but sizes them according to the motors.
My SR5 was carbed and had a mechanical fuel pump. Whatever this problem is, I didn't have it a few months ago, at least to this degree, so it's a matter of something failing rather than being under-specified. The previous pump (the one that's in there right now) was a big beefy generic parts store special. The new one is one of those modern tiny pumps, it's specified for a Camry, so it should be plenty enough.
I'd suspect the fuel filter then. Do you have a bad gas problem down on your island? Can you plumb a fuel pressure gauge onto the rail where you can watch it when you're pushing it at 7K?
On the Truck, I went with a high pressure pump from a Ford van when I megasquirted it. It had a mechanical pump on the head for the carbed motor. "The W3bz" said the Ford van HP pump would work by itself. I mounted it on the fender well. After replacing it twice, I added a lifter pump, one of the small (MSD, I think) square low pressure things for carbs, back at the tank. No more pump problems.
I've asked around about a mechanical fuel pressure gauge, can't find anyone who has one. There's no fuel quality problem here, unless you count the selection of octanes you can buy at a gas station 
The car has gone through some old gas over the last few years though. The filter's new in terms of running hours but I figure changing it out first and seeing it if changes anything is worth a try.
On that era Toyota, you need to make or buy a banjo bolt adapter. You take out the existing banjo bolt and put the banjo bolt adapter in, which has a port that you can then hook up to a fuel, or any liquid, pressure gauge through a line. I've taped one to the windshield before when troubleshooting. You should be looking at like 35-ish PSI over whatever the manifold pressure is. So, at WOT, that would be 35-ish.
I don't think this has the banjo adapter, but it has most of the rest. Nothing like this around? https://www.amazon.com/Excelvan-100PSI-Injection-Gasoline-Pressure/dp/B01JVTX0TI/ref=sr_1_1?ie=UTF8&qid=1488226568&sr=8-1-spons&keywords=fuel+pressure+tester&psc=1
No unfortunately it seems nobody has a gauge like that, I was also looking for one back when I was trying to figure out why the engine didn't run properly on the original ECU, so it looks like I'll have to just chuck a filter and then a pump at the engine and see what happens. The only other possibility is the FPR, and that's a shiny new part, newer than the other two.
Well they tried another FPR on the car last night, that wasn't it. A '90s Mazda 323/Lantis FPR will work on a 4AGE apparently, but it's an awkward fit.
The FPR that was on the engine was fine, it was the pump. The new pump also solved some pinging while moving off that I was struggling to tune out.
Did a little work on the car today and took some pics. New front engine mount:
New gearbox-side engine mount:
This one has relatively less material inside, but it's about the same thickness as in the front mount, which takes a lot more load:
The original wiring harness boot at the firewall had become a joke. The armored vacuum line for the on-board MAP sensor alone is nearly the size of a 3/8" fuel line, and then when the wideband was wired up the electrician had to run it outside of the boot entirely. I didn't want any wires getting sawed at by the sharp edges so I gave it one of my handy DIY grommets:
Here's the old fuel pump that came out, you can see how much bigger it is:
This evening I tried to do check over the AFRs but even though the AFR output showed correctly in TunerStudio, it didn't log properly, so that wasn't all that helpful.
I did the testing while driving next to jersey barriers to help me hear any pinging. Mostly went well, but at one point I came to a stop and the engine sank into a low, slightly sputtery idle, and when I gave it some gas a huge puff of smoke came out. It was dark so I couldn't tell the color, and it didn't have a strong smell. But there's been no other smoking.
Minor update, got the AFR logging problem fixed and did some test runs. Flat-out runs to redline show an AFR in the mid/high 13s, I'll try to bring that right to 13.
Did a little driving school event yesterday with the Corolla and it ran well, it was a pretty busy event and I didn't have time to set up and manage cameras but I wish I did, the car felt viciously fast on the small autocross course that was set up. One of the exercises involved driving with only one hand on the steering wheel, which I thought was going to be a mess, but it was actually doable with a carefully chosen line.
Next autocross is early April.
Autocross was on the weekend. Took Friday off to get the alignment set again after the front uprights had to be removed to get the powertrain out. Seems the shop was simply hesitant to put in an aggressive setting the first time because they got it up to -1.8deg in the front this time. I also took it to get the high beams fixed, after being broken for probably more than a decade now, which was caused by both a worn contact in the trafficator and a broken wire in the harness, turned out to be a much more expensive fix than I expected.
Next, on the night and morning before the event, I was trying to tune out that leaning at higher RPMs on full throttle. I noticed that it would reach frightful readings of around 16:1 at over 7krpm. So I increased the VEs there and....no change. Increase it more, still no change. Set them so high that it black-smokes and sputters at high RPMs, again no change. So it seemed that the lean AFR at these RPMs was false, but I wanted to be as careful as possible to not blow up the engine again, so I set it just rich enough that it won't black-smoke and sputter and called that good enough for the event.
At the event a circuit was laid out that was fraught with hazards, mostly to your time but some to your car. The circuit cut through a narrow interconnecting kart track that had a nasty drop-off on one edge of the pavement. It exited onto a part of the track that was strewn with so much dirt that it was effectively a sand trap, as I found out the hard way on my second run. That led to a slalom and a turn-around cone with enough slick muck on the track nearby to nearly send you backwards into a barrier if you slid onto it, as I found out on my first run.
On my third run I managed to avoid all the debris traps but failed to avoid the drop-off. The car still drives straight but it's been making a light scraping noise when moving since then, I suspect I've bent a brake heat shield onto the disc, haven't had time to check yet. Like most drivers I struggled with the steering through the very tight turns, I should start thinking about a variable EHPS setup so that I can dial up the steering boost for corners like these.
https://www.youtube.com/embed/g9hyBYcOJ0U
At least that run was quick enough for 4th in the new 2WD class. After the event I looked at the ECU data logs and found some sensible AFR readings at high RPMs, oddly enough. It seems that the same problem doesn't crop up in short bursts from mid to high RPMs.
In reply to GameboyRMH:
Good lord, that's like a cross between gymkana and rallyx. 
Dropping off the edge of the pavement just caused some dings and scratches, nothing a quick sand & spray couldn't fix:
Had to pull back timing to less than stock to cut down some pinging at low RPMs:
Now I'm only suffering with the dreaded burst knock problem, where I get one quick bang of detonation when I stab the gas from idle. To try to address this indirectly (since MS doesn't have a burst knock feature) I've been trying to tune the accel enrich...it's tricky.
Looks like the next event will be the autocross all the way in August, there's only one track day in between that falls on the same day as an offroad rally.
Been doing a little driving and tuning on the car over the last month, but just as I thought I got the accel enrich perfected with the use of the "TPS uses %WOT" setting, this happened:
Looks like the TPS failed but it could be something in the wiring, I dropped it at the electrician to confirm the problem.
Good news, it was just wiring, got it fixed. Still haven't quite taken care of the burst knock though.
Just a quick update on what I've been doing, other than tuning. My wiper tank finally cracked right open at the top, so I fixed it with boogers:
Just kidding! It's hot glue. I've become a big fan of hot glue recently. When the aluminum tape on my fan shroud repair let go, I also fixed it with hot glue:
Last night I was looking at the situation with the rear sway bar links and where I would move them. I'm having second thoughts about the plan of connecting them directly to the bottom of the coilover with a bracket, since as you can see there would be no room for a linkage unless I make the bracket huge and long, which would be bad for strength and/or unsprung weight:
The goal is to get the sway bar connecting bits completely above or below the wheel and tire, so that the closest thing to the wheel or tire is the bare threaded shaft of the coilover. Right now the tire comes up to just below the purple spring seat and the lip of the wheel is in line with the upper sway bar link nut (which prevents me from fitting wider wheels). So the other options are to connect the sway bar to the lower control arms (reducing leverage on the upright and putting another bushing in the way), or to use shorter springs and move the connecting ring on the coilover above the tire completely with a much longer link (not too bad for unsprung weight and good for reducing sway bar bind).
There's a 5" long spring of the same rate I could use that would put the spring seat nearly at the top of the threads. If I put the sway bar connecting ring directly below that, it will be about as high up as the spring seat is now, completely above the tire. I could then use a very long sway bar link (maybe from an '08 RAV4) to connect it back to the sway bar. This means no custom fabrication would be necessary. I could also use the current rear springs on the front (same rate) to get those springs completely clear of the tires.
If I'm really lucky I might be able to fit 245/40R15 tires with 15x8.5 or 15x9 wheels...although anything wider than 15x8.5 will require spacers at the rear...or pushrods and bell cranks.
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