I already returned those packs this morning after seeing they were getting 12V (Napa branded, had to get them in a pinch a couple months ago) but ordered new Bosch packs and they'll be here tomorrow. Coils being bad *would* start to make sense of the gradual worsening of symptoms rather than the hard cut of something like a fuse or ECM. We'll see...

A little off topic, but where did you learn how to troubleshoot electrical so well? I'd love to learn more if you have any resources to pass along. Feels like a superpower at this point haha.

 

Doubt you need to remove the plugs, hard to flood a fuel injected engine, LR was just being extra safe. Because you have verified voltage at the coils I am not suspecting either wiring or issue with ECU not providing ground pulse. I could see one coil going bad but not both.

 

I’m just going to say this, simply because no one else has said it, even though it’s probably a dumb thing to say. Roll over switch? There, I said it.

Despite the observed presence of fuel, you might want to put a noid light on the injectors to verify the ECU is pulsing them. Same as spark, fhe ECU is pulsing ground.

if you want to try an ECU/BCU/cluster out of an 04 let me know and I’ll ship them out. The only reason I would swap the cluster is so that none of the components are unhappy with each other through a mix and match when you go back to your originals.

 

You asked about electrical troubleshooting. Learned over years of work experience, but now it's second nature. Lots of books available, but I think the breakthrough for me came when I was able to read electrical diagrams and understand how a circuit is designed to function, without any other written explanation. It gets easier the more practice you get.

For mechanical types, electricity follows many of the same rules as mechanical systems. In particular, DC electricity is analogous to hydraulics. A battery is a pressure tank, an alternator is a pump, wires are pipes, relays are control valves, voltage is pressure, a voltmeter is a pressure gauge, current is flow, a resistor is a flow restrictor, a diode is a check valve, a capacitor is a damper, ground is the return oil tank, the list goes on. AC electricity has similarities to systems of springs, weights, friction, and dash pots. Mechanical items are all visible or tactile, and help us understand electricity that can't easily be seen, heard, felt, smelled, or tasted. Although I have known old electricians who could tell if a circuit was either 110 or 220 volts by touching the wires.... I'm not saying to try that at home.

 

This makes a lot of sense, appreciate it!

 

I suspected that for sure. The only thing I'm sort of hesitating on with that being a suspect is the gradual unraveling of it all. I feel like the switch being bad would be a sudden display of symptoms. I'll check it would though with an MM anyway. Good idea.

And thanks for the offer! The new coil packs arrive today, and depending on the success of failure of that as a fix, I'll text to see if the ECU is pulsing ground, and if it isn't will hit ya up for those bits. Really appreciate the offer. I'm pretty sure the 04 ECU/etc will work on my 02, right?

 

Oh, sorry. I though you had an 04 (despite seeing your sig!!!). The 04 stuff *should* work AFAIK, but there is a definite difference. Hopefully others can comment on the viability and/or sense of using them. I have a 2000 parts truck that runs and drives, I could potentially send you that stuff but I'd need it back in relative short order as I don't want the truck disabled and in the way for too long. I'm willing to do it though, as you were nice enough to loan me the tools for the t-case bearing swap.

I meant press the roll ever switch just to make sure it wasn't tripped somehow. I agree that your issue has been a slow decent to where you are now but I did an engine swap once and ended up with a no start. For whatever reason, and with nothing related to the engine swap itself and obviously no roll over occurring, after hours of chasing everything I could think of I pressed the switch on a lark. I don't even remember what it disables, which is why I said maybe this was a dumb suggestion but I figured I'd throw it out there. Autozone or the like will loan you the noid light kit, although I think I paid <$30 for mine.

 

O4 and 02 ECU's are not mix and match, different interior fuseboxes. I have two 00 ECU/BCU combo I can send, one the ECU throws a IAC code and the other the pass window will not roll down. Probably good to have around as spares for testing which is why I did not throw them out, but they are not good for driving/selling.

 

Welp... new coils packs installed and as the pessimist in me expected, no luck. I put probes in each of the terminals that go back to the ECU and tested voltage while cranking. I recorded one terminal but the other three were identical in their values.


@Extinct thanks! I might end up having to take you up on that.

Also, I just wanted to double check the fuel pump situation and with the ignition on, shouldn't I be getting 12v? I'm not getting anything (pic). A few days ago I used the Nanocom to force the fuel pump relay on for a moment to test that it was working and I'm wondering if that's the fuel I'm visually seeing on the spark plugs a few posts above, not the injectors pushing fuel when I'm just attempting to crank. I'm not hearing the fuel pump initializing at all when cranking or even with the key simply in the ignition.

This whole situation really feels like all the symptoms of a failing/failed CPS despite having swapped in two new ones.

 

I bet the reason the window does not go down is bc of a broken component. I had the same issue drove me nuts for weeks, took the whole interior apart until I opened the BCU and one of the white things was cracked. I took it to an electronic shop and he replaced it, good as new. I have thread about it if you care. I cant find the picture, but it is a small white box.