New member + old truck + dead cylinder

That's a lot of carbon build-up on that intake valve. I've been curious about the condition of the combustion chambers and valves on my trucks heads since I bought it and that image is probably going to be the catalyst for inspecting them soon. Thanks for posting it. What's your plan for the old motor?

 

And this is why I'd always try a bore scope first, and a good top-end clean next if I found nothing.

Granted, now you can clean up your original motor and stick it back in with no concerns

 

Wow. Did it make contact with the piston or something? Timing belt snapped?


Edit: after rereading your first post, I'd look and see if the timing belt on that old motor is new.

 

Didja get the beast running yet?

 

Nah, not yet. I’ve got the motor dropped in, but I’m having a hell of a time getting it bolted up to the trans. Thought I had it lined up and was slowly going around tightening all the bolts.
Got it pulled in to to about a 1/4” more to go and now I just realized the motor locked up on me.
Guess the splines aren’t lined up after all…

 

Helluva a job so far. Looks like you need a new AC condenser now...

 

Well, so I figured out the torque converter isn't seated all the way... Had to pull the motor back off the trans, now I'm just trying to fight torque converter in all the way.

Lol, yeah.... Probably shoulda moved that, but it was already kinda chewed up from whatever bashed the bumper in.

 

I don't see any obvious carnage on top the the piston or anything. And the belt was in good shape, but didn't look brand new.
I did notice the old motor didn't have a thermostat installed and somebody added an electric fan.

Makes me wonder if it was having overheating problems, and that valve just decided it was time to peace out

Not 100% sure what I'm doing with it yet. The bottom end looks fine, so I might just strip it down and keep it as a spare short block.
Unless anybody local wants it for cheap, just so I can get the space in my garage back.....

 

Finally got the motor and trans bolted together!
All the wiring is back together. Just have to sort out the vacuum lines an get a new, rubber fuel line.
Basically just all small stuff now.

Only trouble... I just can't catch a break today. Wasn't ready to start the truck, but I couldn't help but hear it turn over.
First problem, it doesn't look like the fuel pump is coming on.
Second problem. I hear a click from the starter solenoid in the fuse box, but that's it. Doesn't crank

 

Expect some problems. I can even see to check tire pressures without screwing something else up in the process. Fingers x'd for your success.

 

Fuel pump only runs when the engine spinning. Need to get the starter going before itll pump

 

Does this mess look familiar to anybody? As far as I can remember, it wasn’t hooked up to anything but the electric fan that the PO added. Had one wire running to ground, and one wire running through the firewall.
But I can’t make sense out of what on earth all the factory looking plugs are…

I’m thinking it was just a factory harness from whatever those fans can put of.
But I’m just second guessing things now worth the whole no start issue

 

Those look like OEM connectors, but literally could be anything, including fog lights or who knows what? It actually looks close to what I had in back, although that red and yellow thicker-gauge (12-14awg) wires at the bottom don't look OEM, nor does the free-standing blackish wire.

For the thinner gauge (18-22awg) wires that go into the grey factory-looking molex plugs, can you let us know what color they are, knowing that they may have a stripe which is colored as well? There are some common wire colors Toyota uses throughout the electrical wiring diagrams - like white with black stripe is often a ground, for example. Maybe it would help someone narrow things down.

 

False alarm on that wiring. I looked it over again, and it’s clearly factory from whatever the fans came from. I forgot that I cut off the fan plugs when I pulled the rad.

That being said…. Without cutting open the actual wiring harness and probing around in there, I’m at a bit of a loss right now

 

I think I win idiot of the year award

 

Well, the mystery deepens. I plugged in the solenoid/start wire that I missed. And still nothing.
If I jump 12v right to the starter, it turns over just fine. But that trigger wire isn't getting power.

 

Sometimes life throws in a pop quiz. You seem to have passed. Idiot of the year wont understand why he wins.

 

Chase the wire back with a meter until you have power to it. Sucks doing it but 100% success rate guaranteed.

 

Well I'm starting to suspect my transmission neutral switch.
None of the gear lights on the dash are coming on, which seems to point in that direction.

Otherwise, the starter trigger wire has continuity to the relay in the fuse box. But the relay isn't powering up

 

Do you have power to the neutral switch?

 

Actually, I don't even know.... I didn't pull up a wiring diagram to see what's supposed to have power yet.
So with (8?) wires going to it, I wasn't even sure what to look for

 

Understood. I'm using my phone so I don't have the FSM handy to help. I can post the diagram in the a.m. if you don't have it. You're on the right track here. Logic is your friend.

 

Here is a link to the 2000-2003 FSM:

http://toyota.aitnet.org/Toyota/Tundra/2000-2003_Tundra_FSM.pdf

I believe most, if not all, of the electrical diagrams are toward the end of the file.

 

Thank you for that link!
I figured out how to bypass the neutral safety, but still no go.

But something funky is going on with the starter relay. One leg has connectivity with the starter. But all three other legs are hot with the key.

Unless I’m forgetting how relays work, 1 should go to the starter and only be hot when the relay is tripped, 1 should be hot with ignition, 1 should always be hot, and 1 should be ground.

So I must have messed something up pretty good on that harness, but I don’t have a clue what just yet…

 

It all depends on the relay, how many poles it has, what type it is. What is yours, in this case?

The overarching concept for most 5-post relays is simple: You supply constant ground to one post, constant power to another. Then you have three remaining posts: One signaling post, and two switching posts, one switching post to keep the circuit open (default position), one switching post to close the circuit (i.e. 'connected' state). When you apply a sufficient power signal to energize the signaling post, the relay throws an internal arm to close the circuit at the switching posts, thus enabling the circuit.

I don't know what type of relay they're using for IGN. Finding something 'hot' in three places on a relay ... if it's a 5-post relay and pushing power is what you're attempting to do when the circuit is energized and closed, in theory you could have 3 hots at the same time: The always-hot post, the signaling post, and the closed switching post.

Should it be that way? I dunno.

Granted, I'm explaining this is non-EE terms because I'm not an EE. I understand fundamentally how relays work because I've used them in automotive applications my whole life. I'm sure I could understand IGN systems and all this other stuff if I really dug into it, but ... you should probably wait for someone else to help. I'm just trying to offer up a sanity check on relays, since you mentioned it.

 

Well, I found the diagram on exactly how that relay is supposed to work. (and it's definitely not working the way it should)
I also realized that there's a pretty significant drain on the battery.

Short version is.... I still don't know what's going on.

I started unplugging everything I could find, trying to track down the battery drain. Assuming that's got something to do with the start issue, but I couldn't come up with anything yet.

 

Chances are something is grounded.

I'm only asking "just in case": You have a DMM and know the process to track down parasitic drains, right? If not, happy to give a quick explanation. I feel like that's one of the most misundertood things out there.

It's worth noting: Some connectors in the engine bay use the same molex connector - is it possible you have one plugged to the wrong thing?

 

Yup, I do. I started poking around with it a little bit. But I didn't have much time to mess with it today.

And.... I mean anything is possible at this point. I feel like it's going to end up being something stupid like that.
It looks pretty hard to plug something in the wrong spot though.


Hopefully this weekend I get some more time to really start tracing wires and narrowing things down.
Wiring is so simple when it comes down to it. It's just overwhelming how much of it there is in a relatively modern vehicle...

 

I learned a trick working on a family member's 06 New Beetle. These things were famous for killing batteries. In theory a fuse has resistance. Current flow through a fuse can be measured with a digital VOM set to a millivolts setting. It's not much but it is there. Ended up finding the radio amp wasn't switching off.

 

I believe you're on the right track with your thinking in disconnecting everything you can find.

If it were me I would begin again by only reconnecting the ignition system relevant connections and checking to be sure everything is in spec before proceeding. This simplifies the process and isolates each system. Easier to troubleshoot. If something is not in spec then you know not to proceed until the root cause is determined before proceeding. Like you said, it is simple but the mass of wiring can be intimidating and overwhelming.

Also, as mentioned, check all fuses and make sure the grounds are well-grounded and secure on clean, paint/coating-free surfaces.

If you need help with any pictures of the wiring lmk and I will snap a pic of the wiring in question on my truck.