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

OK, looked at the TSB's. I am wondering where your current ground to the block is connected. The diagram clearly shows where the new one should be connected, but hard to tell where the old one was other than beneath the oil filter. At a minimum, that TSB shows you all the ground wires. Not too many, so simple to check.

As far as the fuel suction tube sub-assembly, that is not part of replacing the fuel pump, and as far as I can tell is a dealer part. It may come with a full tank replacement, but I am not sure. The TSB lists a check that can be done to see if that is the issue, though.

Both of these are possible causes, I would lean toward the second one until ruled out.

 

Thank you for taking the time to review those for me TenBeers, I really appreciate it and appreciate your input on them!! I'll review them again more closely myself in relation to your thoughts, thanks again!

 

I just checked, and the fuel tank assembly for a '98 and '02 -'04 is different, so that TSB may not even apply.

Has the Idle Air Control valve been checked?

 

You're right about that fuel tank assembly difference. Just went to dealer parts and showed my favorite parts guy those TSBs, and he noticed the difference too. So on our truck, the equivalent part to replace for the tube suction thingy in the TSB would be the "fuel pump bracket". Overall, this TSB is starting to seem like a long shot - there just seem to be too many "ifs" to it.

Yep, IAC is off the culprit list. Back in January, engine guys said they cleaned and tested ours, and it tested within spec. Then for lack of a better idea, they swapped it with a known good used one. No change - problem was exactly the same with both the old IAC as it is with the "new" used IAC. A malfunction with that sure seems like it would fit the problem we're having though. Lots and lots of forum threads out there of folks with a problem similar to ours, which turned out to be IAC valve issues. Who knows, maybe we've had 2 bad ones?

Also stopped by the mechanic to tell him the bummer news. He was disappointed for us. Such a great guy though. Every time I stop by there, he's in the middle of doing 50 things, and there are cars everywhere waiting for his attention. But he stops what he is doing and comes and talks to me, for however long it takes. So we went through my list of questions, and one of them was back to the AFR gauge. Both he and the angel mechanic (who's been working with him on it) felt like it was starting pretty normally Friday evening and Monday too. And the only variables that are different now are the AFR gauge and the Scan Gauge. Meaning, he had both disconnected Friday and Monday. Then he hooked the AFR back up before I picked it up yesterday, then we plugged Scan Gauge back in immediately after picking up yesterday. So based on that, plus that night it started pretty normally for us with AFR unplugged, today he disconnected it again and unplugged Scan Gauge to see if any difference. So I just drove ~20 miles or so on country roads to get it nice and hot, came home and set the timer - will start it again in ~10 min or so.

OK, everybody HOLD YOUR BREATH! Ha ha ha, there'd be lots of TW members passing out very soon........

 

I don't know much about those 3.4 engines but im wondering if the valve timing might be off just enough to be losing "some" compression at warm starts but not when cold? or something changes the valve timing when hot?

shit, after all that has been looked at and checked, its throw darts at the board time for me at this point.

I did see Jen as she passed by on her first test drive after getting the truck back

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

 

Holy shit, you were in Oregon? You totally busted me!

 

Still excessive cranking after AFR and Scan Gauge were disconnected. Sigh.

Two things mechanic mentioned this morning that I don't think I've shared on TW yet:

1) Spark timing was a bit delayed during excessive cranking.

2) Lots of hydrocarbons (raw fuel) coming out of tailpipe during (or maybe immediately following?) excessive cranking.

So that means the problem CANNOT be a result of too LITTLE fuel going in upon excessive crank starts, right? It's either too much, or an adequate amount of fuel going in at those times, right? Meaning, if it's adequate (not too much), then it's gotta be a spark or air problem, right?

So what makes spark timing delayed? Let me guess - there are only 4 billion possible explanations for that, right?

We still have our donor charcoal canister, thinking of trying that. Mechanic said he plugged a line to the canister (or something like that) to take it out of the picture and therefore feels it's not the problem. But hell, when the donor is sitting here, why not give it a shot, right?

Also, we never did replace the engine coolant temp sensor. We almost did, but chickened out due to it's proximity to the injector wires. Being that the sensor is only $18, I might ask our mechanic to change it.

 

I think you would be wise to change out that coolant sensor. It does play a big part in deciding if the engine computer thinks it needs to do a cold start or a warm start. At minimum, you can cross that off the list.

 

JC!! Jen change the CTS. It's like a $4.00 part and if that fixes it...

 

C'mon!, Steve, if you are gonna use JC to make a point, at least throw in a couple exclamation points.

I'm just kidding around, and drinking, so everything is funny to me. Waiting on my burgers to get done.

Please change out that sensor. I must have lost track, I think I suggest that on page 4.

 

OK, you have done what is reasonable and valid. Now, RUN UNTIL FAILURE and then find the bad part. Drive the truck until the wheels fall off. In the aviation world, it is RTF, run til failure, and repair. Somewhere there is a heat sensitive part,so go drive until you find the weak part. Also known as fly fix fly.

I have 30 years plus of engineering behind me, plus 35 years of mechanicing. Run that SOB until a part fails...then you should be good. Last Sunday, I took out the 68 Dodge Utiline for a spin, hauling a full load down the mountain to the storage locker, then took the 62 M37 Military Power Wagon for a spin, and that old truck did fine, after the battery box cover broke two fingers on my right hand on New Years.

Get a few shots of the best whiskey you have and run until failure. There is a weak component somewhere that no one can find.

Howard

 

That, is some good advice.

Hell, we all got cell phones to call a tow truck.

For all you know, it might fix itself.

 

You guys are the best!

Feeling pretty low today. Just forced myself to go drive it around some more, with no real plan of where I was going or what I was doing. I guess I felt like I should at least try it (starts) a few times before going back to mechanic and trying to figure out what to do next. Got more depressed as I was driving around, just thinking when will this end?!

Pulled in driveway, and nice neighbor that has connected us with all the nice mechanics was outside. Started bawling my head off to him in frustration. He gave me a super nice pep talk. Felt a little better.

Came inside, straight to TW (after lots of doggie kisses of course!). Saw all of your helpful advice/encouraging comments, and feeling even better now.

Thanks TW buddies! Gonna head back down there and insist on having that ECT sensor swapped ASAP!

 

This may turn out to be a good day, after all. Come on CTS!

 

Random fact I wanted to share with TW this morning:

Our mechanic told me yesterday that when he opened up the wiring for the AFR gauge, guess what type of connector he found they'd used?

Good call Koditten, good call.

P.S. Our mechanic replaced the connector with a good one. When he told me about finding that shitty connector, I filled him in on how "my forum guys" had speculated that they'd probably used one of those. We had a good laugh about it.

 

That would be a key part of the hot start system...the engine is flooding since it thinks it is too cold.

Howard

 

How many miles have you put on this truck since the rebuild?
I just had an episode with my 02 tundra racking my brain for a solid week before I figured it out.
I had a battery that was going bad finally take a dump.
I replaced the battery and the truck would hardly start, idled horribly (to the point of a flashing cel) and had misfire codes on 7 of the 8 cylinders and a p0171(lean)
My fuel trims were way off, it was dumping fuel, so idk what the lean code was about.
I initially thought it had jumped a tooth on the timing belt and did a compression test (298k and pretty much ran 215psi across the board , replaced plugs, removed both cats, etc.
Turns out most newer toyotas with drive by wire throttle bodies have an idle relean procedure on the pcm if the battery is discharged for more than 9 hours I think?. I had to drive it about 40 miles down the interstate then stop and cycle the key off and on 3 seperate times while doing this. Truck purrs like a kitten now.
Not sure about 3.4's- never owned one.. But maybe give it a try.

 

Jen
I would not hesitate for a minute to change out the ECT sensor.
At the same time I wouldn't get my hopes up due to the fact that you are getting normal coolant temp readings from Mr ScanGauge and the info he gets is the same as what the ECM sees.

Let it be a pleasant surprise should it work.

 

Thanks for the advice DP! We haven't done this yet but still plan to, definitely. When I talked to both mechanics about it earlier this week, they both said the diagnostic tools they use are not showing any signs of the ECT having issues, but we still think it's worth trying since it's cheap and I don't think it's a huge chore for a mechanic to change out - right? FSM says you gotta drain the coolant - anyone know if you really have to or not? Hoping to talk to mechanic this morning and see if he has time to do it today.

Can't remember if I told you guys the latest or not. On Wednesday, I took the truck back down to him and let him know after picking it up Tues, it started horrible that night. We realized the only variable that was different from when it was starting pretty well for them last Fri and Mon was that they had Mr. Scan Gauge and Mrs. AFR gauge disconnected. Then he hooked both back up just before I picked up Tues, then the horrible starts that night for us. So, Wed AM, he disconnected both and had me take it home again to see how it did. Wed PM, out of ~8-10 starts, maybe 50% of them were decent. Not 100% normal, but ~90-95% normal. Kinda like they were that night that we were certain it was the AFR gauge, because we had those 4 decent starts in a row with it's controller unplugged, then a horrible one when we plugged back in. But, the other 50% were shitty. Reported this to our mechanic yesterday morning, and he was glad to hear there was some improvement noted, and wanted us to plug Scan Gauge back in to see if it made things worse. But we haven't done that yet, because we are pretty stuck in our heads on having that ECT changed before changing any other variables. Anyway, I guess my point is that once again, we're getting some signs that the AFR could be contributing to the problem. I know, I know - just have it removed. But since we aren't getting a more definite indication that it's a problem, it's tough to ditch that thing, because I like seeing what it's reading when we are still questioning what the problem is. Meaning, if I see that thing display some seriously wacked out numbers, at least we have that info and it could be a helpful clue.

Anyway - that's the update for now! Hopefully our mechanic will have time to do ECT today. If not, surely he'd have time next week. Either way, we're hoping to have the truck home this weekend to monkey around with it a bit and see how it does. Gonna be looking for at home free DIY testing/checking advice on TW again soon, so get those ideas cookin' guys!! Happy Friday all!

 

Uh oh. Looks like we're attempting to change the ECT sensor ourselves this weekend. Our mechanic has finally reached the point of needing to charge us their normal prices. Which I am NOT complaining about at all - they've put enormous amounts of time/effort into it and are just now going to start charging us their normal labor time. So hubby's gonna give it another shot and see if he can handle it. I think part of his problem when he chickened out before was that he didn't have the right tool, so we're thinking the neighbor with all the super nice tools may be able to help with that part. Then hubby just has to conquer his fears about the sensor being located right next to some injector wires.

Anybody ever changed their ECT sensor out before? Tips/advice?

Other stuff we've talked about possibly trying:

Different starter relay (under hood one) - easy to do, and an aftermarket is only $26 - again, both mechanics said no indication that this is bad, but cheap/easy = why not?

Clean TB/IAC and replace gaskets with new - talked about doing this before but never got a chance - gaskets are cheap, and it's something we can do ourselves

Add another ground wire?

Charcoal canister - we still have our donor (thank you!). Mechanic plugged a line to ours (or something like that) to "take it out of the picture" so he's confident that's not the problem. But if we can DIY it, and it's just sitting here, seems worth trying anyway.

Other ideas anyone? Mostly I'd love to get some hand holding reassurance on swapping that ECT sensor. Really wanna do it, but we are just a wee bit paranoid about all things relating to injectors (gee, I wonder why?)