Multiple misfires after rebuild ** FIXED **

Looks like my next stop will be to reseat the grey plug and see if the P/N switch starts working.

 

Footnote is on the page after, as you see, it's just the wire position that's different between the two, but the IE1/IE2 connection is definite I think:

 

I know what the problem is, the starter relay pin that goes to ground is not grounding when I turn the key on. I am trying to find out where that pin gets the ground from. Is it from the P/N switch, or does that switch go to the ECU and the ground from the ECU to the relay?

 

Thanks, you saved me from a lot of typing
BUT it is indeed a fine point to make, watch for the asterisks !

 

Toyota's "default" color for ground wires is white wire, black stripe. It's not universal. Grounds can be any color they choose. But generally if it's a white wire, black stripe, it's typically a ground.

In the diagram, you'll see three types of grounds shown:

• Ground terminates into a connector/bulkhead, nothing else
• Ground terminates into a wavy line - that means it's continued on another page
• Ground terminates into an arrow-shape of lines like shown here:

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Under my dash, there's a cluster of white wires w/black stripes (like half a dozen) that are screwed to the dash brace or similar. I wouldn't be surprised to see that connector eventually grounds there. It may or may not clearly show in the diagram.

 

Here are those three types of grounds - it makes more sense sometimes when you put the two pages side-by-side instead of viewing in PDF format, stacked.

1 is ground landing in connector
2 is wavy line indicating your circuit continues at last/next page
3 is where the ground makes it to chassis

And the "M/T" designation on some lines are strictly for manual transmission trucks. Obviously an A/T truck doesn't use the clutch safety switch

 

Just to reset, are you seeing any difference on fuel trims between the two banks? Is there any difference in spark plug deposit color between the two banks? Is the compression good in every cylinder?

The thing I'm trying to drill down to is whether the mixture in the misfiring cylinders is too rich or too lean. You've exonerated the electrical system, so the remaining branches of the fault tree are air and fuel delivery related. Those branches include a sensor lying to the ECM to trick it into adding too much or not enough fuel under certain operating situations but not all of the time.

 

So far it has not thrown a misfire code, but I have not driven it a ton yet. I am going to drive it home today and I'll see if the misfires come back.

 

Oh, and another tidbit of info that may help: See how that junction to ground chassis in my last pic is marked "J3"?

You can search the EWD on that J3 and find what the connector looks like. I don't see this option for your '02 EWD, but with my '06 EWD, there's a supplemental file that shows a diagram with roundabout where connections is made, here's one example - wonder if it exists for '02?:

 

As mentioned a few pages back with the drawing attached, pin 2 of starter relay goes thru various connectors thru the P/N sw thru connectors to IF gnd connector driver side foot well. To find the gnd points, do a word search in EWD for "Ground Points", you'll see most all you need to know about gnds, their connector number, what not.



Location of IF gnd point that starter relay needs....

 

Upon inspecting the grey connector, I found a wire that has pulled out. It is pink.

 

Is there a way to see what it goes to?

 

It is pin 12 on the IE1 connector.

 

See from my diagram above. Neutral safety wire is P, P = Pink.
Number 12 next to IE1/IE2 connector means pink wire is in position 12.
You just found your culprit. Good job.

 

Yay

 

My advice here, and I'll tap @daveeasa for his pro advice

Unseat the connector. Release the OEM pin that's stuck in the connect or using standard process.

If you can, crimp on a new connector, Dave should know what type, maybe?, then insert into the now-empty spot in the connector.

As an interim, you could unpin the connector, try to re-crimp and lightly solder the wire to the pin for now, but it may not be possible. Unfolding the connector is a PITA.

Dave, how do you unpin these damn things again? I always need to look it up every time.

 

I actually have my old wire harness. I pulled the pin from it with the wire. I will just pull the current pin out and solder the new wire with the good pin to the existing wire. Then plug it all in.

 

I forgot you had two harnesses! Good deal.

BTW, kudos to you man. A lot of guys would've lost their shit by now and pretty much been, like, "TO HELL WITH THIS SHIT" and lit the truck on fire to collect insurance.

You have the patience of a dad with half a dozen kids.

 

I couldn’t have held on without you guys. I really do appreciate all your replies and suggestions. I did not feel alone in this.

 

It's part of the ground path from IF to P/N switch that heads to Starter Relay pin 2 as seen in the different pics posted and the one below I circled in blue.

Page 68 in EWD....

 

I swapped out the connector and the truck started right up.

I am back to the misfires. Here is a video of the live data when I just started it up and the misfires are happening:

https://youtu.be/nLI-NevjLw0

 

Great work so far!

 

Have you ever seen any output from O2 sensor @ bank 1 sensor 1? Either when fully warm, or cold? Whether at 3k RPM or idle?

I'm just curious if you're getting any reading at all out of it. It's stuck in my head you won't get readings on one or more O2 before (or until) entering closed loop. But I'm asking just in general, out of curiosity, if you've ever seen anything from it.

 

I don't really know. What I can do is when I drive home today I will do the same video of the data the logger is showing.

Is Bank 1 on the drivers side?

 

I believe the general rule of thumb is "bank 1 is on the same side as cylinder 1".

I'd need to defer to others here, or dig up a diagram. But that rule of thumb ^^ has served me well over the years.

It would also potentially explain why all your misfires are on the odd number cylinders, unless my brain is really f'n fried from work right now.

 

Things have changed over time but Bank 1 Sensor 1 was doing fine back on 6/21 when you did the video. It was going rich(.8) to lean (.1)

Multiple misfires after rebuild

 

I will get a new video today with just the o2 sensor data just to be sure.

 

Confirmed:

 

It looks like the O2 sensor is not working at all.
https://youtu.be/-airnK7bD08

 

I even revved it up to 3000 RPM.