SOLVED! Post 2853 Leaking Injectors, Dealer Techs Rock! Extended Cranking after Engine Swap 3.4L 5vz

Thanks for clarifying . So that first mechanic did put the sensor bung in right after the collector but that's right beside the first sensor then? Sounds like it could be creating a dirty electrical ground for the two sensors behind it then.

 

Wow, I'm learning a ton this morning quite rapidly! Thanks guys! And its so much more rewarding to learn about this stuff, now that I am fairly certain that the stuff I'm learning DIRECTLY RELATES TO THE ACTUAL CAUSE OF THE ISSUE!!! All the learning has been fun, but it's WAY more fun when you know it can help you understand your specific problem. Good reading, thanks guys!

EDIT: Felt like throwing in an edit, just cuz I know how much DP likes them, and it's been a while........right DP?

 

Sounds logical to me, hopefully others will chime in, I'd love to know if this could be what's happening!

 

One could speculate for days on possible installation issues without actual hands and eyes on the job.
The biggest flag to me is the huge discrepancy between the detailed "long" 20 page install instructions/diagrams and the "brief" 1/2 page sheet that came back with the truck. The next flag is the "brief" instructions make no mention of an input to the ECM at all. So who knows what the installer went by, not to mention how well he went about doing it.
All that seems really apparent is the gauge/installation is causing the problem.

 

OK, this is a pretty crude drawing, but I wanted to attempt to illustrate how all the "stuff" is located (stuff meaning all AFR gauge components and our 2 OEM O2 sensors).

This is a diagram of all the sensors on our truck. You can see the 2 OEM O2 sensors - 1 before the cat and 1 after the cat. And as I just learned from DP, the 1 before monitors the fuel mix, and the 1 after monitors the cat.

The red mark is where the O2 sensor is for the AFR gauge.

The blue mark is the "computer" part of the AFR gauge. It's mounted to a rail thingy underneath the truck, right next to the cat. That's the black thing in previous pics that my husband was plugging/unplugging to determine that our starting problem went away when it's unplugged.

The green lines are the 2 sets of wires coming from the AFR's "computer."

There's wires going from the AFR's O2 sensor to the left side of the AFR's "computer."

Then there's wires going from the right side of the AFR's "computer." Those wires do not follow the path I've drawn - hey, it was the best I could do! They come off the R side of the AFR computer, then sort of turn back towards the front of the truck, and come up into the cab through a hole in the floor of the passenger side, and the hole is just next to where you'd reach down to adjust your seat position. From the hole, I ASSUME (don't know, haven't looked) they travel under the carpet, then go to the little gauge display, then I have no idea where they go from there.

Now you are all up to date on the wiring of my AFR gauge. Your lives are complete.

EDIT: Forgot to mention - the crude black circle I drew represents the hole in the floor that the wires come through........and no comments about how if the hole was located where it's drawn, it would actually be a hole in our driveway rather than a hole in the floor of the truck....I'm no artist

 

Uh oh, DP called me out on my SPECULATING mode. Busted.

In all seriousness though, he's right - unfortunately. This is by far the most difficult waiting period for us since the day I learned what a hole in your piston means. So naturally, I keep speculating along with anyone else that will speculate with me, I suppose in hopes that if we all speculate enough, maybe a crystal ball will appear and we'll know WTF is going on NOW instead of having to wait to find out til our mechanic takes it out. And I still don't know when he's going to be back exactly. I know the funeral was this weekend, so I'd guess he'll be back any day now - he's been there 2 weeks, and I'm sure he misses his normal everyday life a fair amount by now. Although, there I go again - speculating about when he'll return.

But yep, seems like all we can say for now, is that we're MOSTLY certain that the gauge is somehow the culprit. Damn. WHY???????? Anybody up for speculating about that?

EDIT: Yes, I agree, WTF is up with the two different manuals for the same gauge, and which one did they decide to go with? Very strange indeed.

So DP, the short version didn't explain an option to connect to ECM? Wow. That is super weird - that's kinda a big deal thing to offer as an option in one manual, but not in another. Weirdness.

 

That's all good. Can you see the actual wires present at the gauge? Important to note is the number, 6 or 7 and colors. Do all the colored wires end at the gauge (connected or not) and do they all emerge from a common "sheath" (coming from under the carpet)? Not concerned with any separate plugs or jacks.

 

Looking now, hold tight! YES, more speculating, my FAVE!!!

 

Damn. Can't get things opened up enough to see the wires going into/coming out of the gauge itself. It's mounted as shown in attached photo, and it's held in place by two bolts behind the face of it that attach to a bracket thingy, so I wouldn't let Eric take it apart, for fear of damaging it or something, or accidentally yanking on wires that shouldn't be yanked on. So no clue still as to how many or what color wires come in/out of the gauge.

BUT. I was able to pick up the edge of the floor carpet next to passenger seat and see that there are 3 wires. Two are black and pretty small/skinny, but one is black and decent sized circumference, so I ASSUME all the skinny little colored wires are inside that one.

Does that tell us anything?

 

there are plastic buttons on each side of that console lower panel, push the middle part in about 1/16" (don't push them all the way through) and the button loosens up and pulls right out. that should be all that holds that lower panel on and in place except maybe a spring clip, then you can see whats connected or not connected behind the gage.

to reinstall the buttons, reset them by pushing the inner pin out so it sticks out past the top of the button, then push the buton in all the way holding it in place then push the button flush to lock it in place.

 

Thanks Keakar. I don't know if we'll do it or not, but I'll show your post to my husband tonight and see what he thinks. Thank you!

 

OK, just called engine mechanic and asked if it's wired to our ECM. They said no, it's just a free standing unit. Not sure if the person I spoke with is the one that installed it, didn't think to ask that. But if he wasn't, then I'm still not 100% convinced that it's not.

But this certainly makes a bad ground, or incorrect placement of the sensor seem more likely.........hmmm.......

EDIT: Just called back and asked if the person I was speaking with installed it, and he did. I asked if he used the brief manual that came in the box or the lengthy manual from the manufacturer's site as a guide to install it, and he said he used the brief guide from the box, and that he would have no reason to bother looking something else up on a website when the instructions were in the box. I asked where it was grounded, and he said right behind the gauge itself. I asked again if it was definitely NOT wired into our ECM, and he said no, that's a big pain the ass to do, they were installing it just for monitoring so they didn't do that. I asked where it's getting power/voltage from, and he said he thought right there by the gauge, from the cigarette lighter. I asked if there was anything questionable about the process of installing it, as far as placement of the wires or components or sensor, and he said nope, it's pretty straightforward. I'm confused. What does this all mean?

 

OK, just called a local place that specializes in high performance German and Japanese vehicles. Picked his brain for the last 20 minutes, super nice guy. Described the whole thing to him, and he said he thinks its very possible the CELs we got in August were trying to warn us of lean condition, so its very possible that our ECM, knock sensor, and O2 sensors are fine. He said its difficult to screw up installation of an AFR gauge, and since its not tied to ECM, he's thinking its got to be the wrong power source was used, and he said something about "if they tied into a sensor voltage line........" Wish I could write faster. He said he could look at it for free, to try to see what was incorrect about the install, then if we went ahead with having him remove it it'd be a couple hundred bucks. He said he'd have no problem at all signing documentation stating that the issue was caused by the gauge being installed incorrectly, but that it could be difficult to pinpoint how it was incorrect, because its so difficult to screw that up. Not sure what to think here. This is so confusing. All I know is that I'm convinced of two things:

1) Gauge is not tied into our ECM
2) Gauge is causing the starting issue somehow

EDIT: He also said (like Sterdog said) there's absolutely no reason we need this gauge, and its strange that those guys said it would be a good idea for us, because our O2 sensors and checking codes if we ever get a CEL is the way to go for our situation. He basically said it's messed up that they put one in our truck and didn't tell us why we don't need one.

 

The above reasoning was derived from the "long" instructions before the different "brief" instructions surfaced so in your case the yellow wire should be the wire for the gauge light.

I had my suspicions about "stand alone" or not. To use it for fuel management is just more work than needed or useful for your stock engine. Those guys sure didn't come off as doing any more than they had to.
It will be interesting to see how it actually is wired regardless of what they said.

Mr Sterdog made a good point about welding fumes contaminating the OEM O2 sensor. In that case connecting/disconnecting the gauge should have no effect.

As far as their claims as to how gauge was wired, they make perfect sense. The cig lighter comes on with key in the on position and it has a ground wire with it, all right there behind he gauge. No need to search out and power/ground it in common with any other engine management circuits.

Now the evil conspiracy theory. This is just campfire talk but what if they crippled the adjacent OEM sensor when welding, figured out what they did, then wired in the Innovate sensor to get things going. Just a theory because if it is wired as stand alone, including apart from any engine management circuits, it just can't affect the running of the engine.

Till tomorrow

 

DP! I'm shocked! Never thought of you as one to propose evil conspiracy theories! This morning was fun educational reading for me on the thread, but now the reading has taken a dark dramatic turn.......I like it!

Really though, I'm just not ruling a darn thing out, so evil or not, gimme your theories, cuz my priority is just trying to figure out WTF is going on.

Called another place similar to the last one, and asked the same types of questions. Overall, his reaction was very similar to the first place I called, like, it's hard to imagine the gauge by itself causing the starting issue, unless..........

Unless wrong power source or wiring. He said if they wired into a sensor voltage line, that could cause some seriously weird shit to happen. And strangely, for his example scenario, he used the IAT sensor line. Which is the only value that we've noted consistently corresponding with the starting issue. Maybe he picked that because we're talking about a hot start issue and therefore him picking that for his example means nothing. Who knows.

We've never seen off the charts weird readings in the IAT values on Scan Gauge - sure, they HAVE to be nice and hot in order for a starting issue to occur, but they are still always within a normal range, based on the conditions the truck is in at those times. For example, if we start it and let it run til ECT is ~195, then shut it off, then attempt to restart it in ~30 min, IAT will generally be a minimum of 70-75, but usually more like 80-90+. I think the highest I've ever seen it go was 112 ish. And correct me if I'm wrong, but aren't those numbers pretty normal, considering all the heat under the hood is soaking that IAT sensor during that 30+ min?

I told him we've not gotten any off the charts abnormal temp, etc readings on Scan Gauge (based on our understanding of normal), then asked him if we'd definitely be seeing abnormal readings on things if they'd tied into a sensor voltage line, like if they DID tie into IAT sensor line, would we def. see off the charts values? He wasn't sure. I think he was getting close to his fill of the free Q & A, but he still hung in there and was super nice.

Let him know we did just recently get a CEL for TPS. Asked him if they could have tied into sensor voltage line for TPS. He said yes, its possible. Basically my overall impression from him was, this is likely a wiring mistake, and there's more to it than just the gauge.

Oh yay, hopefully he's right and this can continue for another 1000 posts, wouldn't that be swell!??!?! I suppose 3000 would be more appropriate than 2000, considering #3 cylinder is the lucky one for me........

 

Been reading from afar, but keeping up best I can. I really want to see where the wireing is tied into.

If you get a chance to poke your head under the dash, look for a scotch lock wire connector. I'm more than betting that there is a wire that comes from this gauge and is tied into some wiring on the truck. I just know these guys would have taken the cheap and easy way of attaching wires. Its gonna look very evident. Not Toyota factory look at all.

I didn't make up that connector name because I like scotch, either...even tho people who use these are drunk or lazy.

 

https://www.youtube.com/watch?v=zsKqXqNhDUw&feature=youtu.be

Just for kicks, I thought I'd share a video of one of our 4 "good starts" from Friday night while the controller/computer of the AFR gauge was disconnected. As you'll see in the vid, it's not completely normal, but it's no where near the excessive crank time that the typical bad starts have been. Much closer to normal. This was the only vid we took that night, but the other 3 "good" starts were identical in sound/crank time. Now compare this to one of our bad ones earlier in the thread. And man, I wish so bad I'd thought to video the crank time on the start after we reconnected that AFR gauge. It was ridiculous, which has been the trend. We feel like the excessive crank time starts just get worse over time. Somewhere along the way we stopped being as organized about filming, so can't say with total certainty, but sometimes it gets to the point of cranking so long that we stop trying, then try again. Argh.

EDIT: Here we go - this is definitely not the worst start/longest crank time ever, but even without it being the worst, you can clearly hear the diff in crank time from the one above........this one was taken on or around 2/4, ~30 min after it was last running. With the AFR gauge all connected.

https://www.youtube.com/watch?v=yTx1Y2PJfn0&feature=youtu.be

 

Me too!! Can't wait to find out.......thanks for hanging in there with us in the meantime.

Scotch lock wire connector. Hmm. Googling that. No clue what that would look like. But sounds easy enough to peek around for it......

No comment.

 

OK Jen, sit down at that desk right there...no, not that one, front row please....Yep! Right there.....

When naming oxygen sensors, and their position, manufacturers use "banks" based on cylinder #1 position. In general (and of course Ford is the one who does it backwards) the odd cylinders are on one side, and the even cylinders are on the other side. Bank 1 is considered the side of the engine where cylinder #1 is located, and bank 2 is considered the side where cylinder #2 is located. So on those vehicles (like the 2nd gen Tacoma) which have 4 sensors, you would have:

• Bank 1 Sensor 1
• Bank 1 Sensor 2
• Bank 2 Sensor 1
• Bank 2 Sensor 2

In this configuration sensor 1 is always located BEFORE the catalytic converter, and sensor 2 after. This basic naming is still used in all situations.


So why would you, on your 3.4 have 2 sensors, being named B1S1 and B2S2? For cost effectiveness, and simplicity. B1S1 may be located after the two exhaust sides join, but technically it STILL is located after cylinder #1, and before the cat. So it is still called B1S1. Up until the 2000 model year, most all manufacturers were using either a 2 sensor or 3 sensor configuration. (3 sensor configurations were used on most of your luxury models, but not always, and would have two sensors located one in each exhaust manifold, then the two pipes would join and flow into the cat, where a single sensor afterwards would be the 3rd sensor)


When running a 2 sensor system, the computer can't identify which bank is running lean, since it is measuring ALL cylinders after the collector. Because of this, if it detects a lean condition, it will richen all of the cylinders evenly by slightly increasing the injector "on" time. If it detects a rich condition, it will lean out all the injectors by decreasing the injector "on" time. The downfall to this is that if an injector is stuck open, or a cylinder is not burning all of the fuel efficiently, then the computer will be leaning out all of the cylinders, and it can cause trouble. That is why most all manufacturers have gone to a 4 sensor system. Sadly the 1st Gen trucks were of the old design exhaust.

Oh, and FYI, the sensor located after the cat has but one purpose: Monitoring the efficiency of the catalytic converter(s) of a vehicle. The information from the sensors AFTER the cat do not affect how the computer performs it's lean/rich control.

 

OK, textbook is open, pen in hand, notebook ready to be filled with scribbles of brilliance........

Makes sense, DP & Sterdog touched on this a fair amount yesterday - good to recap though for sure! Now I'll have a better shot of actually retaining the info by covering it more than once And the logic behind which bank is which is good to know too, makes sense!

Yeah, this part kinda blows. I suppose I'd still have made the same decision to keep my old girl instead of replace her if I'd known this sooner, but it really is a bummer. Wish they would have thought of a better design sooner......

Got it, thanks as always Bama!

Is it summer break yet? I'm ready for ice cream and sunshine and dirt roads in my Taco!!! You guys have managed to cram a lot of wisdom into my normally non mechanically inclined brain, pretty amazing!

ALL of you guys have really helped me tremendously in communicating with all of the mechanics and auto parts people these last few months. A LOT.

Just yesterday I called a place to ask about removing the AFR gauge. I explained where the O2 sensor for it was in relation to my stock O2s. He started saying something about my 4 stock O2s. I was like, nope, I've only got 2. He totally started talking to me in that patronizing way (he was nice though, so I didn't get pissed, or at least not TOO pissed ) and he repeatedly INSISTED that I have 4. I remained cool as a cucumber and calmly informed him that no, I am absolutely 100% CERTAIN I only have two, and suggested he check in the computer, because my truck is a 98 and this is how 98's were designed. He finally looked in the computer and realized I was right.

Naturally, I wasn't gloating like crazy inside AT ALL.

And the gloating honors for that go to................

MY TW BUDDIES! Thanks everyone!