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Haha. Well, this thing is making me want to shoot it, that is for sure.
Tested most of of the sensor circuits from the PCM connectors to the individual sensor connectors, as well as the ASD relay, all checked out good. Didn't get to the O2's yet.
Voltage from the batt to the starter and pdc are also good, not more than a couple tenths of a volt difference.
PCM grounds are good.
As far as I can tell, this thing should be working. But it doesn't.
What I'm not 100% sure on is if the TCM and RKE being disconnected will activate the ASD circuit to disable spark. From what I can find so far, that answer should be no.
I haven't been able yet to chase or check the wiring between the TCM and the trans, or wherever it goes, so unsure what the problem with that is.
Long story, (aside from the fact that I am a fu^%#*ng moron) for those who care, or just want to avoid making the same REALLY stupid mistake that I did:
I have spent the better part of the last three weekends and several evenings trying to figure this thing out, and none of it was making sense. It should have worked.
I tested every sensor, chased and tested impedance on every circuit/wire between the sensors, ECM, PDC, cluster, etc. Many multiple times.
I removed, tested and cleaned every fuse, wire connector, relay, ground*, and contact I could find.
It def acted like the CKP was bad, but it wasn't. The ECM was getting input from the crank sensor, and the crank sensor tested good. I had fuel, and injector pulse, but no spark. It would prime the pump and then shut down, as it should with the ASD circuit.
I even pulled the crank sensor out again, confirmed it was working and the ECM reading it, and the ASD circuit was working correctly by plugging it in, turning on the key, and waving the CKP in front of the body, and the fuel pump would continue to run.
After another exasperating half day of flailing on this, I went in for lunch. While explaining what was going on to my GF, I had an ah-ha moment. Everything seemed to work fine, UNTIL cranking it over.
So, I'm thinking I must have a short somewhere that only happens during cranking. I most definitely did.
After getting the motor in and starting to hook everything up, I realized that after more than year, that I couldn't remember exactly where everything went. So, you start looking at where the various connectors and such want to naturally lie, as they tend to take a bit of a "set" after 20 years in the engine bay. So, I have one set of wires hanging down below the oil pressure sender, that line up pretty well with the two posts on the starter, but I can't tell for sure which one goes to which post. So, I hook them up the way that makes the most sense.
Weeks later, my truck still doesn't run and I am staring at it wondering if my starter solenoid has some internal short or something, so I disconnect all the wires to pull it out.
Then I realize that those same two sets of wires probably also will reach the two big GROUND studs on the side of the block.
I do some cautious testing of connecting them to ground (with a fuse between), and turn the key. VROOOM. (Insert 20 minute string of four letter words and throwing of small hand tools).
So, basically when the starter solenoid engages, and connects to the second terminal on the solenoid- I have been backfeeding 12v+ into the grounds for the TCM, ABM, and (I think) PCM.
With everything hooked up the way it SHOULD be, everything seems to work fine. I had a couple codes for the TPS, but I think I have that figured out too. How it didn't nuke all the computers, set off the airbags, and go up in flames the first time I tried to crank it, I don't know.
But, she is alive, and I will start gently trying to get it broke in, and cross my fingers that everything keeps working.
Well, I did finally paint the grill, so that decision was made.
And, I've made one other decision. It's time to let her go. It's been a sometimes fun, sometimes infuriating project, but I'm ready for something new. I just have too many vehicles now, and need to consolidate into something which fills a few criteria.
I may put a listing up here, but probably going to go through Ebay or a local consignment. Thanks for all of the support and comments through the build.
03-07-2017, 07:48 AM
