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

As someone corrected me, the code you are getting means the signal from the TPS dropped momentarily (not out of range). Since the TPS itself has been eliminated, you have wiring and ECM to consider.

If it were me, here is what I would do:

1. Check ALL ground connections. You would typically get more than one code, but worth validating that the ground from the plug going into the TPS at least has good continuity to ground. If that wavers, your signal will drop out.

2. Check all vacuum connections and check for intake leaks wherever things hook together.

3. Check the TPS connector and wiring continuity, clean things up, etc. Make sure it connects well, no corrosion, and that the wires aren't stretched or stressed.

4. Try that other ECU. They are simple to swap out, it's just electrical plugs.

5. If still befuddled, go bananas and replace MAF and oxygen sensors, and then try any other sensors/valves after trying those (VCV, IAC, etc.) if that doesn't work. You mentioned that the oxygen sensor is missing a bolt, and if that affects the reading (is there an exhaust leak?) it can mess up how the ECM controls the engine.

That fuel trim doesn't seem right, but it doesn't seem that far off either. As complex as it may seem, there are a limited number of inputs that are evaluated to control a limited number of outputs. Garbage in, garbage out. If everything is mechanically sound, it is just a matter of cleaning up the garbage.

 

Ten Beers, thank you for all the helpful input! Will review all of this advise with husband and likely do most if not all of what you are suggesting. Thanks!

Everyone, just called the injector place. He was nice, but as I kinda expected, he basically said we can bring it in for $100 to have them look at it next week (they are also general mechanics in addition to injector services), because he can't tell me anything without looking at it.

I think I'm gonna head down to that electrical place nearby and see what they can find with the free testing they are willing to do.....husband asked them if they'd like us to bring the FSM paperwork on the procedure for checking the starter signal circuit, and they said no. I think I'll have it laying on the passenger seat just in case

 

Right, but I am not comfortable doing this until we talk to our mechanic. He reset our ECM, in hopes of getting codes while we drove it and the current ECM relearned the sensors. So I'm focused primarily on accomplishing that goal, and just want to do as little as possible in "messing with things" to get it to where we feel OK driving it, in hopes of setting more codes to make it easier for him to decide how to proceed when he returns. We are NOT changing the ECM unless/until he says we should. We are just trying our best to follow his instructions right now, because so far, of all the mechanics who have been involved, he has been BY FAR the most honest, dedicated, kind, determined, motivated, experienced, and knowledgeable - I firmly believe if anyone is going to ever get to the bottom of this and fix it and not cause us to go into bankruptcy over a truck, it's him.

 

That first one needs to be checked and verified and its free too. The grounds are absolutely paramount for the truck to run properly. Again, going by memory, but I thought there were 7 ground points on our truck. Anyone could be affecting the ECU.

 

I dare you to disconnect the battery and stick your head under the dash, find the wires that lead to the ecm, pull them out and stick them onto the other ecm. If you have to use duct tape to stick the new ecm back onto the outside of the kick panel until your mechanic can fix it then it is what it is. Hell, I double dare you!

 

You have the code information as well as some freeze frame information from the current ECM, and your trusted mechanic would not likely be able to get any more out of it than you already have. You are in a good situation in that you actually have another ECM to try, which is worth a shot. The worst it is going to do is reset the ECM again, and you haven't really driven it enough to make that a big deal.

If you try the ECM and nothing changes, then you KNOW it isn't the ECM. Then that points to wiring or some other odd sensor or actuator issue.

If I had an extra one sitting around, I would definitely try it.

 

I wish it was that easy. Toyota left only enough wire length/room for the disconnection of the wire bundles, then removal of the ECU. Just not enough room for the wires to connect and the ECU is screwed to the truck chassis for grounding purposes.

It is an easy job, just has to be done in a prescribed sequence because of physical restrictions.

 

Yep. What he said ^^^^^.

Plus, you are all making very good points, but we just aren't doing it til he says so. Period. Not going to be convinced. It's a major organ of the truck, so I want an experienced professional to

A) make the call as to whether it's appropriate to do it, and
B) be the one doing it

He mentioned we might need to "flash" the new one before installing if any features from each truck are different, so that alone is reason enough for me to decide we are waiting for him. Pretty sure the only diff between our current one and our donor is the TRD Off Road, but all else is identical. And I'm not sure if it would need to be "flashed" because of that little difference, but I'm not going to rely on google to make that decision - I'm going to rely on our mechanic to decide that.

 

Great news! Just called the electrical place nearby that my husband talked to, and he's gotta be related to our angel mechanic, because he's an angel too! He said they can test the started signal circuit (1st item to check in FSM for hot start issue) for free, and they don't have to disconnect battery or clear codes or anything! Told him all of our worries about not messing with stuff due to ECM being reset/our mechanic's instructions, and he assured me all will be OK as far as what they will do. I asked if they can check the igniter under the coil packs, cuz we've heard that could be the issue, and he said they can test enough stuff to help us rule that in or out anyway and point us in the right direction. Told him about the TPS code and TPS being replaced, he said often on older Tacos that code and the rough idle is because the TB is dirty. Told him I think our gaskets on IAC and TB were reused, not replaced. Anyway, it sounds like he may be able to help us at least some without messing up what our mechanic wants us to do, so I'm heading there RIGHT NOW!!!

 

Way cool. Some positive news always appreciated. Hopefully we can get these "hooked" on finding the issue. You find the right guy and he will eat, drink and sleep the problem...maybe not drink, leave that to me and others

Sorry, still can't find that booze. Got one more place to check. Maybe Sunday, gotta behave, tomorrow is Valentines day.

 

I was harping on the starter signal to the ECM thing a few weeks ago. You were confidant your guy had checked it. However, it never hurts to double check that kind of thing. It might take all of 5 minutes.
Should it test bad, don't let them sell you a new starter. Much cheaper and better fixes can be done.

 

Sorry for the delay, this is prime desert exploration season.

Here is a 3.4 man trans t-body from the front. The round black part with a plunger and accordion boot contacting the throttle linkage is the dashpot. The dashpot adjustment screw can be seen with the yellow paint. The actual throttle stop is the screw above and slightly to the left. Also with yellow paint.


Same view of Gen's auto trans t-body with no dashpot. The throttle stop/screw is hidden.


Rear view of t-body showing the diaphragm housing of the "throttle opener" (center). Common to both auto and man trans.
The throttle shaft is spring loaded to stay open a few degrees by itself. Any vacuum over around 5-6 inHg on the "throttle opener" overrides the spring and closes the throttle against it's stop (normal idle position). So for all practical purposes the throttle plate remains slightly open only when the engine is off or just starting.

 

OK, got lots done this afternoon. Went to that electrical place, and those guys are on the cookie list for sure. No diagnosis unfortunately, but they did verify 100% that it is definitely not anything related to the starter. For sure. Asked them 1000 questions to be REALLY sure, and they knew their stuff and I'm confident/satisfied it's not that. They were super nice and listened to the whole sad story, and charged zero dollars. Very cool place. They thought it was likely either a fuel issue or an igniter issue. Said an oscilloscope would really be best to check the voltage to the injectors, over a noid light. They suggested we clean the TB and IAC valve, and replace the gaskets, since gaskets are cheap and labor done ourselves is free, and see if any difference. Their overall advice as far as the new TPS and the code still being there and the rough idling and the reset ECM was drive it.

And you all know how I've been nervous to do that. But I felt a little braver when I left there. So at first I headed home, and was about to turn it off, then I thought, fuck this. Backed out, cranked up the Waylon, and drove probably about 50+ fast miles on country roads. Idled rough the whole time, but I kept a close eye on the AFR gauge and Scan Gauge and just tried to relax and keep driving. While begging the truck to give me another CEL. She didn't listen, but at least it was nice to get out and drive on a pretty day.

Then I ran by dealer parts and picked up new seal/gasket for IAC valve and TB. Hoping husband can tackle cleaning those this weekend. Brought my new parts buddy up to date on where things are at - he said he used to have a 98 Taco too! Asked him why he got rid of it, and he looked all sad and said he wished he never did. Told him how much it made my day to hear that

Then I decided to drop by the new parts store we found that carries OEM stuff for Japanese vehicles. That place is just awesome. Great prices, and pretty much everything they carry is for our truck. And the guys are super nice, no long lines, hell, hardly anyone in there ever. Talked to the same guy that helped us last weekend when we picked up the thermostat, plug wires, etc. Explained to him that our tailpipe O2 sensor is missing a bolt/screw - supposed to be 2, but there's only 1. And he referred us to his trusted mechanic, which is a place we've been told is great before. And is a couple miles from home. He told me to tell them he sent me, and gave me his card to take.

Decided to swing by there just to chat and see what the place was like. Big sign out front that says "we specialize in older cars" Went in and asked the lady at the counter how much they'd charge to do the smoke machine (parts guy told me that's one of the few places around that has one). The mechanic turned around and started asking me questions - what kind of truck, did we have an EVAP code, etc. Wound up talking to him for like 45 min, telling him the WHOLE long sad story. I know you guys are gonna say don't do it, but we're thinking about letting them take a look next week. He seemed so confident that they'd be able to pinpoint the issue within 1 hour, or maybe even 30 min, it is just hard to not be tempted to believe him. He kept saying stuff that made PERFECT sense, like how during the engine swap you gotta be super careful with the wiring harness, and if even one connector was mistakenly left plugged in when it was being removed, that could be the issue. And how just one tiny little ground wire out of place could be the cause of the whole thing. And how the connectors to the injectors could definitely be failing, because if they are taken out/put back in enough times, they're toast, plus they get corroded over time. And how the noid light test is good, but it's really only showing if the relationship from the ECM to them is OK. At one point, he said something like, "this is probably too much information" and I was like, "not at all, I've been on a Toyota forum 24/7 for like 3 months, I know EXACTLY what you are talking about" - (thanks guys!!) It was just refreshing to be able to talk in such specific detail about the things we suspect, it's hard not to have some faith that maybe they could actually get to the bottom of it fast. The mechanic at that place has a 97 T100, and an 85 4 runner. I don't know, I really do love our mechanic, it feels like I'm cheating on him to even consider this. But for a $109 diagnostic hour where it sounds like they would ACTUALLY do some diagnostics, it's awfully tempting to see if a different set of eyes might pick up something else. Argh, I feel like such a piece of shit even thinking that. But I want my f'ing truck fixed ASAP too!! Ah well, we've got the weekend to kick it around and tinker a bit ourselves. We'll see.........

Happy Friday everyone!! Thanks for sticking with us through the good times and the bad!!

I was enjoying one of my most favorite Waylon songs so much this afternoon while driving, and it occurred to me that Valentines Day is coming up. It's such a pretty love song and it fits well with a holiday like that. I think you should share it with your special valentine - it's very sweet. Enjoy!

https://www.youtube.com/watch?v=UsNnKIabYmg

 

Did you like the look on their face the moment they realized you knew what they were talking about. Doesn't it feel good to easily undersrand what they are saying? One sided conversations about your truck are dead and gone.

You are an official car head now and nothing anyone can do can take that away.
Enjoyed the tune, even out of the shitty speakers on my tablet.

Later

KO

 

Thanks K! Oh yeah, guess what husband just did? Disconnected that stupid AFR gauge!! He's rechecking the timing belt right now, so he's got it running, but once he's done and shuts it off, we'll do our 30 min start and see if having the gauge off changes anything. Wouldn't that be great!

 

Yeah, I know the different parts and how they work. My comment was trying to figure out exactly which of the two he was talking about.

 

I keep forgetting it's barely cocktail hour out your way. I guess I will stock around for the next 30 minutes or so.

 

Bama, was it my post referring to the bell shaped part? I was referring to that diaphram on the left in the last picture.e