Crazy thing happened, now car won't start

[essial]

OK, I'm driving down the road feeling pretty good -- I adjusted my TPS sensor (due to it idling low before I ran seafoam through it), and now it's driving like a CHAMP, and it's properly down shifting (automatic) when pedal is pressed down. Well as I start down one of the hills on the way home, my rpm just goes to zilch, and gas does nothing (I now think the engine shut off). I shifted to 2nd and it seemed to come back up for a second but then again back to zilch. Now when I turn the key it just keeps turning over trying to start, but does absolutely nothing else (but there's no weird sounds, just sounds like it's normally trying to start). The engine doesn't sound weird, fluid levels look good, and not a single drip is falling underneath the car. The tow truck guy just towed it 1/4 a mile to my house. Any idea whatsoever happened, and any idea what could be the problem?

(Note: It's a 7M-GE automatic)

[essial]

Update:

Error code 12 and 13 are being reported.

Update 2:
Took a tension cable out, attached a new spark plug, cranked, and no spark. Then we disconnected the ignition assembly from the distributor and tested for current when starting, again, zilch. We then made sure all fuses were solid, and that the relay clicked (it does). I then reset the ECU (unplugged battery for 10 minutes), re-tried to crank (no crank, just kept trying) and no go. Re-ran error code, only error code 12 reported this time. I'm really thinking it's the ignition coil, and that this may have something to do with the random 'bumps' I'd feel while driving down the road (most pronounced at low speeds). I noticed it a lot worse on the way home today (when the car failed).

Now the ignition assembly looks crazy big, but when I searched advance auto I saw this:
http://shop.advanceautoparts.com/web...RPTUNEAMS_____

Would this work for the car, or would I need something else (and any suggestions).

[cre]

Both of your diagnostic codes are CPS/distributor related. Test the CPS and inspect the wiring to it. Just because a code is gone after a reset doesn't mean it was bogus, many codes only appear if the engine has been run for a certain period of time or other criteria are met.

http://www.cygnusx1.net/Supra/Librar....aspx?S=IG&P=1

[essial]

Originally Posted by cre

Both of your diagnostic codes are CPS/distributor related. Test the CPS and inspect the wiring to it. Just because a code is gone after a reset doesn't mean it was bogus, many codes only appear if the engine has been run for a certain period of time or other criteria are met.

http://www.cygnusx1.net/Supra/Librar....aspx?S=IG&P=1

Yeah, I'm about to go to bed but all the places I've read talk about the wires being known to shake and disconnect. This weekend I'll go through and focus on that area, thanks! Looks like this week my 1 1/2 hour commute (each way!) will be with a 97 olds with only 3 breaks (4th is metal on metal). Good times.

It also seems that this MAY be related to my intermittent shaking (like a singular 'thump' here and there while driving, but not consistent), we shall see!

[cre]

Shake loose? Not in the MKIII. They'll oxidize, get frozen together, or wiring may get melted... It's quite seldom that you find wires which have vibrated/shaken lose. The connectors Toyota used are VERY solid. One common complaint with regard to the CPS/distributor is the wiring getting damaged from heat from the exhaust manifold.

[essial]

OK I'm obviously new to this whole thing, and I guess I'm just dumb, but I've spent an hour looking on the internet, in the repair manuals, as well a repair manual I own, and I can't for the life of me find the CPS sensor on my 7MGE engine. Where I would expect it to be I see the alternator, on the other side I see nothing obvious. There IS a sensor looking thing towards the bottom of the engine in the back on the passenger side, but I'm pretty sure that's the O2 sensor. The thing on the front at the top is the TPS sensor, which is new and I've adjusted several times already. Until I get paid on friday I really can't do much anyway -- and if it IS the CPS sensor, the cheapest I've found is $375, the second cheapest is $550. At that point I might as well go ahead and replace the entire ignition system as the other parts are pennies compared to that. Really sucks too, I was about ready to start work on restoring the inside of the car as it was running so well...

Anyway, if you could give me some sort of clue as to where the CPS sensor is, I'll check it with a voltmeter tomorrow. Thanks again for your help and guidance!

I will say considering I've had to replace half the stuff in the engine bay already (just dumped about $700 replacing the entire cooling system as just about every component was leaking, including radiator and water pump), I am really starting to learn how this thing ticks (or doesn't tick ).

Update:
OK, I took apart the distributor cap (I also noticed the 'vent' hole still had a cap on it.. isn't it supposed to be open?! and looked inside. Didn't see anything obviously bad, but at least I see the pickup coils referenced by the ECU. I think I'm just going to wait until this weekend and pick up a feeler gauge so I can do all the tests. I'm thinking it's either the distributor cap, or the wiring. A continuity test should be able to let me know which.

Oh and last thing I haven't mentioned, ever since I got it it has had this weird thing about starting where it would simply do nothing when I turned the key sometimes. It may be 5 seconds, 30 seconds, or more of holding the key down before it suddenly turns over and cranks up (before this issue obviously). Lots of times it just cranked up fine.. Would this be related or another problem altogether?

[cre]

The CPS is built into the lower half of the distributor on the GE. The GTE omit's the distributor but still has the CPS. Hence my referring to it as
"CPS/distributor".

I've no idea why you're calibrate the TPS multiple times. If you don't trust that it's in good shape test it and if needed replace it... it is a wear component after all.


EDIT: Refer to the TSRM for the Toyota Supra for the most complete information about your car. TSRM = "Toyota Service and Repair Manual". They're year specific and MUCH better than Haynes/Chilton manuals. If you don't have a copy there's a link to an online version for a '90 in a thread in the MKIII FAQ section as well as links to download PDFs from a couple other years. Most stuff is relevant regardless of year when it comes to the mechanical components and testing of sensors; Wire colors and plug configurations may vary though.

[essial]

The first time I adjusted the TPS sensor because it was idling extremely high and the person who bought it (less than 6 months, new at the time, ago) set it in exactly centered. At the time when I was adjusting it I simply messed with it until the idle was around 800 (which it stayed there for a long while). After sea-foaming my car, the idle was then instead at 500rpm (yet still idled smoothly, amazingly enough), so I bumped it back up. Yes, I do now understand that such function should be handled with that idle adjuster screw thing, but hey -- when I got this car I didn't know what a distributor was, much less how the EFI system worked

And finally -- yes, I am referencing the manual at http://www.cygnusx1.net/Supra/Library/TSRM/MK3/ so I hope that's the right one. I'll be going down the list, step by step, taking my time. I don't want to waste money on a distributor if it's simply a bad wire!

[cre]

There is no idle adjustment screw... The idle is *supposed* to be entirely controlled by the ECU.

I'm not even going to start on the whole pumping baby oil and naptha through the engine thing...

[essial]

Ok for the ignition coil I'm getting 0.4 ohms primary, and open circuit secondary (negative on top pole) so I'm assuming that's a bad coil. For the CPS/distributor stuff I'm getting (in order of G1, G2, NE) values 228, 222, Open circuit -- with negative on G. I checked 4 times, with several hours between the first two and second two checks, and got the exact same results.

So I'm thinking this happened:
1) Ignition Coil failed/spiked, sending large amounts of current down the wire, burning itself out in the process
2) Spark hits distributor, burning out the first thing it sees (NE sensor)
3) ECU looses ability to determine RPM and promptly stops trying to send sparks (not that sparks would hit anyway)
4) When key-on-engine-off with diagnostics mode jumpered, the ECU notices "No signal to G1, G2, or >>NE<<".

So, does it sound like I figured it out?


Here's what I'm planning on buying on friday, unless you have anything to add:

(I already have a set of brand new spark plugs)