2017 5.7 FFV Stalling (new)

Hi All,
New as a member, but no stranger to the posts - y'all have been posting and discussing great stuff that is very helpful, kudos and thank you for that.
After reading possibly every last post about various stalling issues, I do believe that I have a new one (there was one post that sounded similar, but never concluded).

My 2017 SR5 4x4 CM FFV (just under 80kmls, had it for a year, never used E85 but guilty of cheap 87 grade) with the large tank started cutting out; I don't mean stutter or delayed starts - it cranks and fires perfectly every time, idles however long you want without hiccups, no problems ever shifting into gear or reverse.
But on cold (45F or less) mornings (98% of the time), after I coast down my pretty steep driveway (almost 20%) and get onto the road, the engine just cuts out from one second to the next. No check engine light, no stutter, just out. Dash stays lit as normal, torque disengages, so I coast to the side and re-start (either rolling in neutral or standing in park). Engine starts fine, within 30-200 feet (lately on the shorter side) it'll do the exact same thing on level ground... and that repeats again and again and again. Never stalled going UP my 18% steep driveway.

Codes I've been getting fairly consistently were
C1241 ABS voltage
B158F Navi voltage
engine:
P0339 Crankshaft pos sensor
P1603 engine stall
P1604 startability
P1605 knock control CPU (only got that once)

I found the youtube video by Advanced Level Auto tracing a similar matter down to the fuel pump connector, though he was getting an additional indication for it (which I didn't), which was P0230 (fuel pump primary circuit). Anyway, unplugged it, made the contacts tighter, re-plugged. Then I changed air filter, plugs. Oil is good.
Eventually I had Toyota look at it, they swapped the battery and put a new crankshaft pos sensor in, gave it a clean bill of health.

Next day problem keeps happening.
P0339 still came up here and there (leading me to believe that this is likely not a problem with the actual sensor).
So I pulled the PMP FFV relay, thinking it may have to do with the fuel driver module messing up a non-idle pressure voltage, assuming I was bypassing it.
Toyota took another week long look at it, drove it for 50mls, said everything was fine; matter of fact they indicated that pulling the relay may have reset the driver module. They put the relay back in when they took it in, and as I'm driving off the lot, the engine stalls twice (lot exit about -15% angle).

Recently I've been getting less and less codes when the stalling happens, now it's only
C1241
B158F
P1604
Thinking these are all consequences, but not root causes of the stalling.

All that said - there are (predominantly warm) days when the truck runs 100% perfect.
But when it stalls, it does so within the first half mile and then every consecutive stone throw (never at idle, and never up a steep hill).

Engine bay clean as a whistle, all wiring is clean and tight, hoses are soft and flexible like the truck rolled out of the factory yesterday.

I just cleaned the throttle body (which was dirty as heck), the MAF (which was clean).
Next I'm taking a fuel sample to make sure that I don't have brown soup on the bottom (could explain the downhill condition triggering), and I have a new fuel pump driver module coming (because I just don't trust it).
Hope the combination of clean MAF, throttle body, clean fuel and a new driver module will fix it, will keep y'all updated.

By the way, per Toyota Corp, neither the fuel pump recall nor T-SB-0166-19 apply to my truck (despite it hitting all the qualifiers in the TSB).

Posting this (hoping I'll figure it out) mostly to add to the library, but obviously I'd highly welcome any advice if this sounds familiar.

 

Starting here may be helpful.
https://www.tundras.com/threads/inf...ol-density-issues-owners.100347/#post-3481415

 

Yeah, not having an extended crank issue at all though.... attaching some idle data. Wondering if any of these fluctuations are meaningful to anyone (or normal).
From the outside, while all that's going on, there's no perceived stumble, hiccups, interruptions while all of that is going on.

 

Battery would have been my first guess based on the assortment of random codes and the cold temperatures. Broken or corroded ground wire would be another thought. Fuel pump issue is maybe third for me, but a definite possibility.

 

Have you looked into bypassing the fuel pump control module to eliminate that as a possible source of your problem? There are some threads here discussing that issue.

 

Thanks!
@KNABORES Battery was swapped by Toyota a few weeks ago. Fuel pump was my original go-to, but that would throw flags like extended cranks and/or degrading power (everything runs fine until it stops completely).
Loose / bad ground wire is technically possible, but considering how clean all wiring is and how intermittent the stalling is, I'm drifting away from that idea.
Electrical fluctuation is a concern for sure (no idea how much of that could be normal), especially with the nav and ABS codes I'm getting. Good input!

@AZBoatHauler saw & thought about it, and did (somewhat) bypass by pulling the PMP FFV relay (not the fuse). Worked on the way to the dealership (could have just been a good day, that's the problem with the damn intermittency), but not the last time I used that trick. Either way, I'm getting a new fuel pump driver module in the mail this week and will swap it out to be sure. Good input!

I'm also wondering if my voltage regulator in the alternator might have an issue?? That would be my next approach if all else fails.

My current working theory is bad fuel/water on the bottom of the tank (that would explain the issue popping up after my driveway) combined with a previously dirty throttle body, possibly in conjunction with a bad connection in the driver module that causes voltage fluctuations is the mortal combination.
I'm feeling that the stalling may happen right at the time when the gearbox is wanting to shift to second gear.
Shifting/tranny problems by themselves would throw codes, but I'd think that the throttle body valve closes between shifts (right? like letting off throttle between shifts on a manual), which between dirty fuel and poor air flow / too much fuel in cold temps in combination could cause the stalls.

 

Dirty fuel is plausible. There’s a ground strap on the transmission that someone found broken on theirs recently giving them a myriad of issues related to shifting a 4x4 system issues.

 

@KNABORES ground strap on the tranny - that's a new one - I'll def look for that one and report back!

I just also found something interesting in my own data.... the last graph above (yellow and blue lines on top) seem to show a collapse of my rpm at about 24 seconds. It looks less intense than it is since this is a logarithmic graph. The rpm actually dropped to 151 rpm for a split second (intervals at 0.6 sec).

 

Did Toyota check your ALC% while they had it?

 

The alcohol density issue only impacts cold starts. Never heard of a stalling issue and the miscalculation only floods the truck when cold.

 

Frankly I don't think they checked much of anything...
When I use the BlueDriver tool, alc % is fairly stable at 11% except when it drops to 0 or jumps to 20% at times (example of drop below).
That said, I'm starting to not trust much of what I'm reading on the OBD anymore - look at these idle data, I was right there and I can tell you 1,000% that the idle RPM never went up to almost 8,000 rpm
Enlarged, the short term fuel bank 2 has some pretty big drops (green) - but again, I'm starting to wonder how reliable the reader is.

 

@AZBoatHauler I'm understanding from other posts that there's actually no alcohol sensor in the Tundras, it's merely a calculation-based value.
Speaking of other posts, has anyone ever actually found a fuel filter outside the pump assembly on 2.5s?

 

Everything you post symptoms and diagnostic wise is erratic operation and data. I would be chasing down an electrical issue first.

 

That doesn’t make any sense to me but I don’t think it matters for this discussion.

What would the computer use to base the ethanol value?

 

https://www.tundratalk.net/threads/flex-fuel-alcohol-sensor.760496/page-2

 

So it’s using the O2 sensor to try and determine the % of ethanol in the fuel… I’d call that a sensor.

Makes me wonder if fresh O2 sensors would resolve the creeping ethanol calculation issue…

 

Just put the PMP FFV relay back in, took a fuse to my lightbars out.
Pretty clean except now I'm having split-second winters (see engine coolant of -8F when it's 72 outside).
This is getting borderline comedic. Going to hibernate til I have had a chance to look at what's in the tank.

 

https://www.tundras.com/threads/res...ge-level-with-bidirectional-scan-tool.123799/

Post#1
Reset your alcohol fuel % to 0.

It may help

 

11% is the right amount. Normal fuel has between 10-15% ALC

 

Tend to agree - 11% (even if slightly off) should be close enough to the crap they sell you at the station (not their fault).
Also wouldn't address the whole intermittency of stalling, or the craziness that appears to be going on in the electrical system.

Purely posting data from idling, I don't get how at one point the temp drops, a minute later the voltage drops, then the air density spikes, a minute later the trim drops, RPMs read sky high (when they're not), evap pressure goes nuts... trying to find two things happening at the same time consistently from different angles, seems there's no rhyme or reason to anything. In the meantime, engine is purring like a kitten.
Following the latest electric change (pulled LEDs fuse and re-installed the ECM relay), at least the ECU voltage seems to have stabilized.

 

LEDs, especially lower end ones, tend to cause quite a bit of electrical interference. I haven’t heard of your particular problems before, but don’t know how yours are wired in. Did the problem start coincide with the install of the LED lights?

 

Good point. After spending $$$ on Diode Dynamics and Baja on cars previously, I went cheap(er) and installed a TSC Travellerx as follows: Amber glow via relay triggered by DLs, white beam via relay triggered by factory brights. Months later I installed some Osram bar and used the wiring from the factory fog lights (disconnected factory foggers, wired in the Osram).
Both LEDs have been installed for months until this stuff started happening. The only one that's even getting power without brights or fogs activated is the amber glow of the TSC light, from which I just pulled the fuse (as mentioned above).
Technically, the relays are still hooked up, but nothing is getting any juice now. I could just unhook both relays to be 101% certain.

 

Update: Swapped Fuel Pump Driver Module for an OEM, managed to get some fuel from the tank, though I think it's from the top, not the bottom. Fuel is crystal clear (meaning no water or debris).
OBD reader upon start very, very stable - but about 2 minutes in, I started getting erratic values from all kinds of sensors again.
Engine seems to run even smoother than before.
Not sure what to make of the OBD value drops (never two sensors at a time).
Technically ready for a test drive, only that it's warm now, not exactly the conditions it used to stall - so we won't know until it gets cold again...

 

Failure/stall at 2nd to 3rd gear upshift, twice.
Feels like downshifting is getting clunky now overall.

Also found this: https://www.tundratalk.net/threads/2007-dc-5-7l-engine-stall.97347/

 

Toyota installing a new fuel pump today and performing an injector cleaning. To be continued...

 

how's the new fuel pump working out??

 

They didn't finish it Friday, hopefully I'll get it back today...

 

Well, they didn't touch it Monday either - to make a long story short, I solved the problem by selling it to the dealership and getting a different vehicle altogether.
For some reason, T purchased it for full market value, I tend to assume they either know how to fix it and didn't tell me, or they'll flip it at auction and take a minor profit.
Other than not fixing the problem, the dealership treated me very well.
Either way, I need a vehicle that runs reliably, so I bought a different brand (not going bi-turbo Tundra), and paid through the nose for a 6 year, 100k mls service contract.
This truck has been down on and off since late October, it's March today and I lost patience dealing with it.
These things are great trucks when they work, which most of them do - guess it wasn't meant for me to continue driving a Tundra.
Really sad on one hand, since I had plans to swap the lift, change wheels, add LED headlights, swap the grille.... but it wasn't meant to be.
Guess this closes the thread unresolved/resolved.
Big thank you to @KNABORES and @AZBoatHauler for your input and follow-up!!

 

One way to solve it, what did you jump into?

 

Glad you got some kind of resolution, bummer you couldn’t keep your truck. My BIL unknowingly bought a 2016 FFV Tundra and had some running issues that did include the longer crank to start. We went down the FFV rabbit hole and had some success but the problem didn’t go away. Ended up being a non-OEM MAF sensor that was causing all the problems. Swapped for a Hitachi and all is well.