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

Shot that right down,,lol. Didn't dig deep enough. Thanks DP.

Just checking all avenues.

 

Thanks DP. How do you check it? Is that what we are checking when we do the jumper wire/timing light thing to see that the light shines within the tick marks between 8 and 12? Or is that checking some other timing thing when we do that?

EDIT: Just found this on the web about the 5vzfe and ignition timing:

ELECTRONIC SPARK ADVANCE SYSTEM
THE ELECTRONIC SPARK ADVANCE SYSTEM MONITORS THE ENGINE CONDITIONS USING THE SIGNALS (INPUT SIGNALS (1, 3, 4 TO 6, 8, 10, 1I)) INPUT TO THE ENGINE CONTROL MODULE FROM EACH SENSOR. BASED ON THIS DATA AND THE PROGRAM MEMORIZED IN THE ENGINE CONTROL MODULE, THE MOST APPROPRIATE IGNITION TIMING IS DECIDED AND CURRENT IS OUTPUT TO TERMINALS IGT1, IGT2 AND IGT3 OF THE ENGINE CONTROL MODULE. THIS OUTPUT CONTROLS THE IGNITER TO PRODUCE THE MOST APPROPRIATE IGNITION TIMING FOR THE DRIVING CONDITON

 

Yep. That is a technical explanation of the info I mentioned earlier. I just didn't want to get too technical on ya!

 

Gotcha, thanks Bama!

So does it seem possible this could be a faulty knock sensor? We did notice the timing was retarded that one time, which would indicate the knock sensor IS doing it's job, by retarding the timing, right? Apologies if we've already covered this - I'm still getting a basic grasp on all this timing stuff!

 

It is possible, yes. Probable, no. But yeah, I wouldn't rule it totally out. The reason I think it is not probable is that the ignition system ignores the knock sensor input until AFTER the engine has actually started.

 

Another thing to note is that you ran premium in the engine for a little while. During that period of time do you remember the engine doing anything funny? In theory the engine would of been able to advance the timing a little more without causing pinging with the premium gas because of it's higher octane number.... If it didn't knock with premium maybe that will give you a clue that the knock sensor could be involved?

I'm not sure if that's relevant or not. I don't know how far the ECU on your truck can adjust for premium gas considering it was designed to run on regular.

Another thing that comes to mind again is that when you ran the premium gas for a bit, the gas could of had a higher ethanol content than what you've been running in the past. That could explain why the injectors junked up quickly even though the last guys say they cleaned them. If they left all the old lines in the truck then running E15 or E20 could of caused an issue. Ethanol gas has a nasty way of freeing deposits up in the fuel system, though it usually takes a longer period of time than a few fillups for it to cause any sort of issues.

Anyways I'm rambling. Just a few thoughts that came to my head now that your talking about the knock sensor and the engine adjusting it's timing.

 

Jen and her truck, Frank. Forever.

 

Hey there! Nice to see folks stopping back by the thread!

I have some updates:

The bad news: still no clear diagnosis yet.

The good news: Stopped by there this morning, and he's got our old ECU pulled out! Didn't want to bother him so didn't get a chance to talk, but I went to put a few things in the cab for him, and saw that it is OUT. Hurray! He's going for it! I left a note in the cab for him saying (thanks to some VERY kind souls on TW) we should be receiving donor igniter AND MAF sensor later this week to try - yay!

The other good news: The reason I stopped by was so I could..........

PICK UP MY FREE LOANER CAR! Can't believe they do that for people! Granted, it's a craptastic little Escort sedan, complete with a nice big dent in the bumper and squealing brakes, but hey, it will get husband to and from work so I can keep our Civic to take the 4 legged kid to the park every day like I used to (soooooooooo much needed to help me stay sane with all this stress!), run errands, pick up cookie ingredients etc. So excited about that! Can't believe they do this for ZERO charge, wow! Such nice people. They have been so honest about everything, and so nice. I still believe firmly that this guy is going to figure it out, it just might not be tomorrow, or even next week. But he's got that determined attitude, and he's so thorough about looking at everything before ruling it out. And we need that bigtime. And having extra wheels in the meantime makes a HUGE difference.

Gotta go, headed to the park now!

 

Hmmm. You've got me thinking Sterdog. Will go back over gas receipt dates later in comparison to the date that we noted the retarded timing, and see what we can see, then review your post again. Seems worth giving some thought to anyway! Thanks.

 

Glad to hear it, crossing our fingers and paws it gets figured out finally!

 

Gotcha. You're right, if it ignores it til after the engine is started, makes it seem less likely that it could be the culprit. From what I can tell in the FSM, those knock sensors are a real PITA to get to, but next time I hear from our mechanic, maybe I'll just mention that if he ever winds up getting that deep into things, I don't think they've been checked so might be worth doing. Thanks Bama!

 

Thanks PeeRunner! Nice to see ya stop by! Have a good one buddy!

 

Lovemyacolots don't know if you have been reading this thread, but they had similar hard start problems and lean errors. replaced the MAF sensor, which if I followed the thread you haven't replaced. It's at least worth a read on what they replaced vs what you have.

http://www.tacomaworld.com/forum/1st-gen-tacomas/364310-chronicles-high-idle-post-tune-up-3.html

 

This is my thread which is referenced. I'm afraid I haven't read all eleventy-billion pages of yours, but I have loosely followed it. I pity your plight. I'm sub'd now, so if I can help in anyway please let me know.

 

Thank you guys! Reading now!! And MAF on the way thanks to a kind TW soul!!

 

I've read all the thread, but over the time it is difficult for me to remember everything they have done. I do know she suspected it was used/new, but they found before photos and suspected it was not.

Thanks to this thread, I purchased a Ultra Gauge, and one of the settings is MAF sensor. I daily drive a Corolla and have that MAF on and watch it, it goes all over the place, however my car has no issuers. For her Taco, I think as you thought, maybe t's dirty even with a good reading (i think KEaker has similar problem). I think she is getting a donor MAF, so I thought maybe your thread might help.

Also LMTL, my gauge shows what your does with after an hour soak time it will show "80 degrees" when the outside air is 35 (Seattle). I will watch that IAT while I drive and it goes down to what the outside air is after 30 seconds or so.

 

So far I just quickly scanned through your thread, sounds like you looked at a lot of the same stuff we have been! Anyway, from what I could tell, you were most recently saying the hot starts have mostly gone away. Is that right? Any update on that issue - is it fully resolved with replacing MAF, or still a little finicky? Our MAF has been cleaned twice by two different mechanics - wonder if we should get more aggressive with cleaning ours (since it sounded like you kind of did that, right?). Although we do have another on the way, thank goodness! Can't tell you guys how incredibly happy I'd be if we ever find the solution to this, good grief!! Thanks for joining the thread!!

 

jen, he swapped it out with the one on his 4runner and it made a world of difference in how it ran even though it looked clean and tested ok.

that said I didn't see him mention if it resolved his hard warm starts but I don't think he left in it that long to test all that, I think it was just a quick test ride to see if it made any difference in his stuttering issues, which it did.

 

Keaker pretty much summed it up. The donor fixed my hesitation issues. I was about to order a new one, but I figured I'd give it a last ditch agressive cleaning. This fixed my P0171 code and hesitation issues. It's only been a couple days since I cleaned it, but my hot start seems to be getting better.

This is somewhat nuanced...before, I would crank and after several seconds it would barely stutter to life and idle low/rough until I tapped the gas, afterwhich it would assume business as usual.

Post cleaning/as the computer adjusts, it actually fires before I can let off the key but still has a funny sputterish kind of idle. However, it now quickly corrects itself without me having to tap the gas. I'm sorry for my poor description, it's an odd event that I can't easily relate.

But like I said, it fires very quickly now, if somewhat strangely, and it seems to get better everyday. As I have more opportunities to test it, I'll try to update you. Hope this helped more than confused!

 

Where are you going to get your from? Dealer, or aftermarket, or ?

Thank you for telling me about your situation, I have to admit it's making me hopeful that perhaps it could be our issue too! Please keep posting updates about how your hot start issue is doing - whether it becomes 100% normal, or if it continues to be better but a little off, or what. If we wind up needing to spend a bunch on getting the correct MAF, it'd be great to have as much insight as possible before opening our wallets again........