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

Bama, if the injector services we're having now don't fix the problem, can I buy you a plane ticket to Portland so you can do all that stuff on my Taco please?

EDIT: this is another excerpt from that article I linked in my last post, anyone think this guy is onto something?

"You guys do realize that when you unplug the air temp sensor you're just putting the ECU into "Limp home mode" which means it goes into its most basic form of running/starting and doesn't listen to any sensors. Its just uses the base map built into the ECU.

This "limp home mode" will allow the car to start no matter what, if all of the mechanical engine things are in check. This is why it does not mean its the air temp sensor causing the problem, and I can absolutely guarantee that replacing the air temp sensor is not going to fix it. Its the first thing a million people have done. And it doesn't work. Plus if you want to see if it changes anything when the air temp sensor is cold, just take it out of its holder and spray some cold air on it. The truck still will not start.

I think the real issue is the coolant temperature sensor. Its getting heat soaked from hot coolant leaking towards it after the engine shuts off. This is a common thing that happens on every vehicle(except the hard start). I have not fixed my hot start issue yet, but I am thinking of moving my coolant temp sensor to a different location(right now its right beside the exhaust manifold). I'm thinking of moving it to the other side of the engine and seeing if this fixes the problem.

I'm going to get another sensor relocate it, leave the other one in place, and when the truck won't start I'm going to plug the other one in and plug it into the other side one and see if it starts. I truly believe this is the reason for the hard starts when the engine is hot.

I just want people to stop buying Air Temp sensors! It won't fix it, I promise!"

Edit #2: Just found that my local community college offers a class called "Fuel and Emissions Control Systems" - covers service of fuel storage and delivery systems: fuel injection, emission controls, and other electronic engine controls. Includes DSO use and exhaust gas analysis.

Seriously, if the damn injector services do not resolve this, good grief, not sure what to do beyond going to school to fix it myself! By the way, what is DSO?

 

Makes lots of sense. Running the truck in open loop is a quick way to kill the cat/converter. All that extra fuel overloads the cat and you get to buy a new cat to pass emissions.

You won't be able to tell a bit of difference how the truck drives open loop/vs closed loop, you will have a check engine light after a bit.

DSO=Digital storage oscillascope

 

Has your guy done any live data logging? There is got to be something that we are missing. If he can start logging some of the key parameters, we might be able to get some idea on which direction to take.

As of now, I can't offer a thing. I want to know the true answer to this dilemma. Seriously, I find myself thinking about this at the oddest times...and I'm getting tired of not knowing what's going on with your truck.

I said earlier that the modern fuel injected engine is very universal in design. Maybe check out some totally different manufacturers and models forums to see if this issue is reported on other makes. Honestly, I'm throwing darts now and I don't like it.

 

Mechanic just called, he said we'll have results from the Injector Doc tomorrow. He said when he pulled them, the one at #6 was labeled #4. Not sure what that means. He said none of the 6 looked new or like they'd been thoroughly rebuilt - it looked to him like they took 2 out of another motor and had them flowed and sort of rebuilt, but not all fresh and new and clean like the rebuilt ones he usually sees. I asked him if he'd like me to try to ask those guys where they had them cleaned/tested before, and/or ask them again which 2 came back "bad" - he said let's wait til we get results from his guy then go from there.

He's replacing the 2 hoses he found cracks in that were simply put back on by the engine guys, and he also cleaned a bunch of dirt and debris out from underneath where the plenum was. His words were "it makes me mad to see that they put this back together like this, why would someone do that when you've got it all taken apart?" This is not the first time he's expressed this sentiment as he discovers details left behind by their work. Told him, "it makes YOU mad, tell me about it!"

He said he saw fuel vapors coming out of #6, so he's really hoping that's what the results will show - that #6 is leaking and we can finally have a final diagnosis. But he said if that's not it, he's not going to charge us for the injector stuff! What an angel. He said he doesn't know what the hell to think if that's not it. Told him I'm thinking about taking a course on fuel issues at the community college if that happens, and we'll put our heads together! He got a kick outta that......

I told him my idiot theory of the day was the MAF - that engine guys told me they'd cleaned it, but at this point I question everything they've told me. He said it's working properly, he did check it. I told him I'd read a story online about someone with same issue who found their IAT sensor inside their MAF was caked with a millimeter of dirt, then after he cleaned it off, issue was resolved. He said he'd double check it, but was pretty confident we would have gotten a CEL if it was not working properly.

He loved the cheesecake! It was in one of those springform pans, the kind that looks like a round cake pan, and it has a little lever on the side that you push over to release the bottom of the pan from the sides. He said, "my wife knew how to work the pan" - I got a big kick out of thinking how brilliant this guy is, troubleshooting wiring issues, fuel issues, etc, and yet he needed assistance with my cheesecake pan. Too cute!

Sorry popcorn people, sounds like the agonizing wait continues til at least tomorrow.....

 

I'm getting tired of popcorn

 

Me too! We need a pizza emoticon on this damn site!

Wait, scratch that - we need a J & B emoticon!!!

 

I never said anything even remotely close to "a pump can have pressure and not enough flow". If you think I did then by all means bold that part.

Measuring fuel flow and determining if there is sufficient flow are different things. Measurements of flow volume over time at pressure are fine but are meaningless unless you have a specification to compare against. Show me a published "flow" rate for a Tacoma pump or current for that matter, hot or cold. Without one your limited to exactly what it says in paragraph 2 of that link, just as I said.

 

Ha! YOU find yourself thinking about this at the oddest times! Join the club! Good to know I'm not alone in my obsession though!

Tell me what exactly you mean by the part I bolded. I will gladly try to gather some info! Sounds easy enough to do.......are you talking things like ECT vs IAT vs TPS type stuff that SG II would tell us, or ??? I know he's had that crazy expensive computer scan tool hooked up to it for a variety of purposes, but have no clue what he's looked for, found, or not found with it. Great thing with him is I feel very comfortable throwing ideas out and asking questions, so tell me what you're wondering about and I'll ask him!

Also, in your last post, you said this:

"Makes lots of sense. Running the truck in open loop is a quick way to kill the cat/converter. All that extra fuel overloads the cat and you get to buy a new cat to pass emissions.

You won't be able to tell a bit of difference how the truck drives open loop/vs closed loop, you will have a check engine light after a bit."

What were you meaning made a lot of sense - the excerpt I posted about the dude with the ECT sensor placement theory? Clue me in K!

Holy crap guys, we are getting way too close to 1000. That's it, I'm going back and deleting some of my more idiotic posts.........

 

If he is using a the Toyota TechStream software on his laptop, he is capable to log the stuff you listed above. It will just be in the form of a graph. He should be able to see quickly if any of the sensors listed above make any drastic changes, just by looking at the graph. I can't remember off hand how many sensors he can log at one time, i think it depends on how powerful his laptop is. I think I can easaly do 4 on my netbook, but it is a bit slow.

 

Got it. So I should ask him if he's got any data (graphs, etc) that he could email me, then I could post them?

 

He should be able to do screan shots and email them anywhere.

 

I posted the Toyota spec for allowable injector leak and it was more than just "vapor". I was not there so I can't make a call on that or the degree that 1 slightly leaking injector would inhibit the engine from starting on the 5 good injectors.
On the MAF/IAT, they can be working just fine (no code) but supplying the ECM with inaccurate data, because they are dirty. The ECM has no idea how accurate the sensor readings are.

So here is a hypothetical scenario, we have a hot start issue. We also have a cumulative bunch inaccurate sensor data from the MAF, IAT, ECT and that issue in my PM. 3 of those values are temps, hmmmm? Just tossing it out there.

 

DP, I forgot about that - you're right, you posted about the injector leak thing - shit, now I'm worried that maybe this isn't going to be the issue.

Wait, dumb down the last part of what you are saying. Are you thinking, what if some, or even one of those sensors is dirty and therefore reporting inaccurate data to the ECM, so then it gets all confused and tells the truck to send an inappropriate amount of fuel during the hot start times?

Holy crap, if this winds up being a dirty MAF, I will scream very very loud. That's something we could have done ourselves - husband has done it before and has the cleaner out in our shed. We talked about it, then I forget why we didn't - I think we just chickened out, or had given up on our little Harbor Freight rainy driveway BS DIY crap at that point. Not to mention the majority of you guys told us to make sure that thing was clean. Not to mention the engine guys swore up and down they'd cleaned it. Good grief. I wish I had a mountain bike - I'd ride over to the new mechanic's house and pull the MAF myself RIGHT NOW.

 

I think (previous posts) it turned out that you have a slightly different MAF/IAT sensor than mine but I will restate that many folks pull the thing, look at it and clean the apparent sensor. This ends up being just the IAT as the MAF portion is sort of hidden.

 

So you're thinking maybe the engine dudes thought they thoroughly cleaned it all but perhaps actually didn't? What was your theory exactly in your last post? Thinking about calling our mechanic to discuss this more, and also ask about emailing us any data he might have recorded......

DP, also, what did you mean by this: "and that issue in my PM"

 

Kmon y'all....19 to go.

 

OK, not sure how helpful this stuff might be, but we did record a few numbers off Scan Gauge during good/bad starts when we had Taco home -

Good start (hood up)
ECT 180
IAT 48

Bad start (hood down, 1/2 hr mark)
ECT 185
IAT 90

Good start (early morning)
ECT 44
IAT 49

Good start (had let idle til ECT came up to 200 on last start, then shut off and restarted ~5 min later)
ECT 200
IAT 53

Bad start
ECT 179
IAT 78

Best we could ever tell was that the only consistent factor was that IAT always had to be above 60ish to produce bad start, and the higher it was, the longer the crank time. But the goofy thing is, that sensor's readings always seemed to correspond appropriately with its environment - the heat the engine gave off with the hood down, and the value rising appropriately in that situation over ~30 min. But what the hell do I know?

EDIT: Just saw your post below DP. Now I'm really wondering about this.........trying to decide if I should call our mechanic to throw this out there, or wait to see what his injector dude finds......so sick of trying to make decisions like this. Can't believe we're almost at 1000. This morning I saw where we were and thought, maybe everything will be resolved by 1000 and post #1000 will be me saying, IT'S FIXED!!!!! Not looking likely........

Oh good grief, just realized even if it is that those sensors are dirty, we wouldn't know it, because he's going to have to put the injectors back in to be able to start it after he cleans those sensors (assuming he hasn't already cleaned them), so we'd never get to find out FOR SURE which one it was - the recleaned injectors, or the damn sensors being dirty. Eye yey yey, if I don't get a SOLID answer to what the f'ing cause was, I will literally go insane.

 

Yes, actually more along the lines of "a little here, a little there and some more on the other one" all adding up to "enough" for an issue but for the most part yes, you got it.
The ECM isn't really confused, it just does it's thing based on the data it gets from the sensors, accurate or not.

 

Those #'s seem realistic but IAT would have to be compared to ambient, still it does not look to extreme. But then I don't know exactly at what point too extreme is.

 

Oops, sorry - ambient was between ~45 and 60 for all starts. Unfortunately we weren't consist about recording that, but I know for certain it was usually right around low 50s.