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

Actually that is not always true. Toyota, as well as a few other manufacturers do not have the pump-prime. The Tacoma will not energize the pump until the engine begins to crank.



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CIRCUIT DESCRIPTION
In the diagram above, when the engine is cranked, current flows from terminal ST of the ignition switch to the starter relay coil and also current flows to terminal STA of ECM (STA signal).
When the STA signal and NE signal are input to the ECM, Tr is turned ON, current flows to coil of the circuit opening relay, the relay switches on, power is supplied to the fuel pump and the fuel pump operates. While the NE signal is generated (engine running), the ECM keeps Tr ON (circuit opening relay ON) and the fuel pump also keeps operating.

 

It means when you turn the key to the run position, you should hear the pump run for a few seconds.

 

Mine does. I turn the key to on and you can easily hear the pump prime.

Edit: I went out and checked, and sure enough, no hum from the pump when I turned the key. I don't know what I was hearing, if anything. So I apologize for my misinformation. It was not my intent to step on BamaToy's toes with that statement. I would recommend his advice over mine any day of the week.

 

No worries Brett!

 

Dirty Pool, can you email this to me, or post the link to it? Just called mechanic and asked if they would do this for us, as we're paranoid to disconnect TB and do ourselves, with new engine - would feel better letting them do it. Can't get the image of it saved in a format I can send to them. Thanks!

 

http://ww2.justanswer.com/uploads/skyvisions/2008-04-16_204916_95_t100_isc.pdf

Or is this a longer explanation of the same thing?

Emailed both to him, figured out a way to save your image correctly. He said they did a fuel pressure leakdown test, and the PSI drop was within specs. He's going to review the emailed links and call me to let me know whether this was done, and if not, I'll take it up there and they should be able to do this for us. Pending that, we may just replace IAC valve regardless, cuz we gotta move on at some point here, but it'd be nice if this test would absolutely tell us replacing IAC valve will fix problem, so hoping it will tell us. Will consider fuel pump still also, but maybe see how the IAC test and possibly replacing it goes 1st, then if still issues, try fuel pump ourselves. Thanks guys!

 

Chilton/Haynes strikes again. Once again, I don't make this stuff up.
I have never seen it in print but I believe this "feature" is to prevent the fuel pump from continuously pumping in a wreck. Say you crashed, the engine is not running, the fuel system is cracked open somewhere and the key is still in the run position. This feature will stop the pump instead of spraying fuel all over the smoldering heap.

There was a thread just a few days ago where the fellow did a pump r+r based solely on "Can't here the pump with the key on" and "double checked that when the fuel line was off". He lucked out and the pump was in fact bad.

Going back thru that IAC, both the electrical test and a re-clean (to be sure) is cheap, then you will know.
As far as pump prices, keep in mind much of what RockAuto sells consists of "bought up" part inventories. Wholesale from Toyota for just the pump is $275.
The 2 RockAuto links you posted for the pump kit/strainer and gasket are correct.

 

Thank you so much DP!

The attached files are from a FSM which I believe is correct info for our truck.

The "comp" file is an illustration of the fuel pump and all its associated parts - I'm concerned that the Rock Auto pump/strainer kit don't look like they include the fuel sender gauge and lead wire. Shouldn't those be replaced as well? From talking to mechanic, it sounds like his Denso pump/strainer kit wouldn't include those either, and his is 2x the price.......

The "ovi" file is a step by step diagnostic process on checking fuel pump. Step 4 explains something that to me, sounds like it would require dropping the tank to actually get to the pump to test it. Is that correct? Also, everyone who's said there really is no 100% full proof method of verifying the pump is working properly, does this sound like something that would verify it? If it requires dropping the tank, I suppose at that point just replace the damn thing anyway, even if tests fine, but still, I'm curious as to whether this would be a 100% guarantee of finding out whether pump is failing or not.

Thinking of emailing these files to mechanic as well, to ask whether ALL the pieces in the "comp" file would be included if he did pump for us, and also to ask whether they did step 4 on "ovi" file (99% sure they didn't, but just to be 100% sure).

Thank you so much for continuing to help us - we felt very discouraged last night, over the fear of this being an ongoing money pit we've gotten ourselves into, but we have to keep trying and moving forward, so I really really really appreciate everyone's continued help/support.

 

Yes that's the whole enchilada.

Like I said before these pumps start failing around 175K. When they quit you are walking. I would find room in the budget for the pump even if IAC work fixes the running issues, just as good PM.

 

^ yep

 

Thank you DP. I see what you're saying about fuel pump regardless, and believe it would be the smartest way to go. Just called a Toyota dealer to ask if their Denso pump/strainer kit for $380 includes:

Fuel sender gauge - no, its $170
Lead Wire - no, its $22
Fuel Pump Bracket - no, its $143

Good grief. Parts guy emailed me photos that include part numbers, and a quick search on Rock Auto for all 3 additional pieces revealed nada. Googled # for sender gauge, and so far not seeing much.

Do these additional parts need to be replaced? A few pages back, I posted links about a guy who's wire that goes inside the tank to the pump was totally charred, and some plastic clip/connector was melted - he assumed those charred wires were his real problem (he was having same hard warm start issues we're having, and tried everything under the sun) as opposed to an actual failing pump being the culprit, but obviously replaced pump as well at that point.

So that's why I'm curious what you guys think about whether those additional 3 parts I listed above would likely need to be replaced or not? If so, and we wind up being forced to get them straight from Toyota to ensure correct brand/quality parts, good grief, an already pricey fuel pump replacement just got a whole lot more expensive!

 

Toyota can be really wordy. In simple terms they are saying test the pump by hot wiring it direct. This bypasses the ECM, circuit opening relay, starter and crank shaft position sensor, all normally required for the pump to run. Additionally it provides a few resistance values of the pump motor that might provide some clues to pump operation.

The RockAuto kit contains exactly what is shown on their site. A few of the little grommets are for other applications and not needed. It is all you need, many folks skip the big oval gasket. When I think about skipping a little part like that, I ask myself "how has your luck been running?". The kit does have a significantly improved filter/screen from the original.

Here's the kit from the outside.


Another fellow mentioned "inspecting the inside of the tank". This is very important and alone a good reason to drop the tank. Then you can take it inside (with good ventilation) for a good inspection and cleaning if necessary. Use a mirror to see the upper areas inside.
On a pessimistic note, if there is evidence of water (patches of rust) you may have found the root of the injector problems.
So with that here's a smiley, enjoy. Check the date.

 

I know I am just some guy on the net and there are plenty of others but once again I don't make this stuff up. If it's conjecture I will state it as so. I know what's in the kit because I have bought and installed them, 3 times.
That fellows post with the fried wire should be considered a freak occurrence. Forget the other 3 parts.

 

No, I'm absolutely not implying you're just some guy making stuff up - it's very obvious to me that you know exactly what you're talking about, and that's why I'm so grateful to receive your continued input on all of these things. I'm sorry if it's annoying that I keep hammering different versions of the same questions - it's not my intention, just trying to be sure I look at as many potential additional costs up front before spending another dime, as right now I'm feeling like I didn't do that before the engine decision. How could I have though - we had no clue that all of these other potential parts we're looking at replacing now might have been faulty then?!??!

Emailed mechanic the helpful how to on testing IAC - taking Taco up there now for them to perform these tests. Told him how now we're concerned that if our pump needs to be replaced, what if we find that tank is rusted inside, and that others (you guys) have said rust in tank could be cause of injector failure. He agreed, but said he saw no signs of rust in our fuel filter or injectors or rail. He said he has no reason to believe we have rust in our tank, but a new tank would be $600 if we did need to replace it. Good god, I actually asked him to please shoot me now.

 

DP - I'm sorry if I offended you somehow, I am so grateful for your input - can't stress that enough!!! Honestly, please don't think I'm questioning what you say/think, I'm just totally confused and stressed about this whole thing and desperately want you and everyone else's continued input!!!!!!! Please don't ditch us, we are seriously freaking out about all the extra costs and are even contemplating cutting our losses at this point and selling Taco. Gonna drive up to mechanic for IAC test now, praying to god we get some sort of positive way to move forward after that.

 

Back again.
No prob, no apology needed, not feeling your implying anything at all, I just like saying it. In fact your dedication, bordering on fanatic, to learning not just the "what" but the "why" and the "what if" that is a refreshing challenge to many of us. Hang in there your in the home stretch.

I was going to mention how the filter can trap water in it's belly and subsequently rust. Your guy not seeing any is good news.

 

I have to agree entirely, this has been a great refresher course for me.

 

LOL, next class will be rusted up ADD and locker actuators. NO NO NO, I didn't say that! As you were Lovemytacolots, you didn't hear anything.

 

Aww, thanks guys! I needed to hear all of that! Not that last part though DP Have no clue what you were referring to there, and let's keep it that way for now

Just got back. They tested the IAC valve, and it tested fine. Naturally, they couldn't duplicate the hard start, so then I was back to looking like crazy electrode lady Said they found some dirt in a line to the charcoal canister that they blew out, but otherwise, still scratching our heads. He's still 100% convinced our fuel pump is fine - we talked in GREAT detail about the testing process they did, and he is really starting to convince me that the only reason to replace it would be PM, but otherwise it truly is fine. Basically told me to take it back home over the weekend and see if the dirt in the line thing made a difference - but it was obvious from the looks on their faces that they didn't think it would, nor did I. Said no charge for the testing/charcoal canister line thing, just bring more cinnamon rolls. At least that part was awesome.

But.

I could hear them starting it at different intervals, and I knew they weren't waiting long enough in between to duplicate it. I didn't want to point that out, cuz it's awkward for a "self taught mechanic" and a female at that to tell guys that swap engines all day how to do their jobs.

So.

I purposely hung out in the Taco in the parking lot a good long while (coincidentally, ~30 minutes from when I'd last heard them start it, for some weird reason). Called husband w/the update, and he started yelling at me asking why I didn't have them put new IAC valve in, to which I replied, if we were going to do that in the first place, then why in the ********** did we have them do the ******** test?!??!??! He agreed. Started it, and it totally did the hard start thing. Of course, the two senior mechanics were inside out of earshot. But, a junior mechanic was right in front of me working on a truck, and he stopped what he was doing and looked up at me, as if to say, THAT DIDN'T SOUND RIGHT! I jumped out of Taco and was like, YOU HEARD THAT, RIGHT? He said, yep. Ran inside, asked 2 senior guys if they'd heard, they hadn't, but then came out w/me, and I pointed at the junior guy and said, HE HEARD IT, HE HEARD IT!!! Junior guy said it sounded like starter silinoid (sp?) - not knowing what the hell that is, but being that it sounded expensive, I about starting crying at that point. Told senior mechanic husband was pissed that I didn't have them replace IAC valve, and he and I had been arguing over doing that in spite of ours testing normally.

Senior mechanic took charge. He said he'd put a used Denso IAC valve in, then we could drive it over the weekend and see if it made a difference. I jumped for joy at this idea.

And.

IT IDLED MUCH MORE NORMALLY ON THE WAY HOME!!!!!!! AND, I HEARD THEM START IT 1/2 HOUR AFTER THEY PUT NEW ONE IN, AND IT SOUNDED NORMAL!!!!!!!!!!!!!!!! PLEASE PLEASE PLEASE PLEASE LET THIS BE THE ANSWER PLEASE!!!!!!!!!

Will go back Monday regardless, to either have further diagnostics if this isn't the solution, or pay them for a new IAC valve. You guys think we should roll with the used one they put in if no more warm hard starts this weekend for $80, or have them swap it w/brand new one for $200? I guess that's just something I have to decide, but if anyone has a strong opinion on that I'd love to hear it.

Pray for us that this is it. I realize I probably sound like an idiot - there are way worse problems in the world than this - but this has been one of the hardest things I've gone through thus far in my life, so to me, it's worth praying over, and I'm not even a praying person!

Happy Friday you guys, thank you for sticking with me!!! Love my Taco World Buddies!!!!!!!!!!

 

FUCK!!!!!!!!! Just started it, 30 min after arriving home. Horrible crank time. Seems like fuel pump is the only stone unturned at this point, right?

They said they cleaned MAF/air temp control sensor, obviously it's not the IAC valve, they said they checked the engine coolant temp sensor, checked all vacuum lines/vent lines. They tested our coil packs very early on in the process, so I asked today if it'd be worth retesting those, but both senior mechanics immediately said there's no way those could be the culprit based on the symptoms we're having. I brought up leaky injector again, and we talked about how we'd see black smoke from tail pipe if it was that, PLUS all injectors were cleaned/tested and 2 faulty ones were replaced.

Guys, is there ANYTHING else that could possibly be the culprit at this point, besides the fuel pump?

Is there any chance that this IAC valve being used could mean it's somehow f'ed up, and could therefore produce the EXACT same symptoms (shitty warm starts, great cold/hot starts) as our last IAC valve???? Meaning, would there be any point in replacing IAC valve w/brand new, or is it definitely absolutely time to rule that one out?

Also, there's no chance that junior mechanic could be right about starter solenoid, is there? If the answer to this is the dreaded, it's possible, ballpark of cost on that????