Aftermarket fuel pump install w pics (flex)

After battling with the dealership over flex cold start issues and 81% alcohol density reading. I was able to get them to agree to do the TSB. I'm out of warranty, so they told me the price and I walked right out knowing they would replace the pump assembly with a new pump assembly that contains the same model delphi pump. I decided I would do the pump replacement myself through other means and have them reflash the ECU.

-Followed @Sumo91 's godsend of a post on the his install (https://www.tundras.com/threads/urd-fuel-pump-kit-install-w-pics.73822/#post-2284985) and ordered URD's pump/filter upgrade with the Deatschwerks 255 LPH pump (https://urdusa.com/urd-2007-tundra-fuel-pumpfilter-upgrade-kit/)


Once I lowered the tank and found there were three fuel lines running to it instead of 2 like nonflex, this was discovered by almost ripping the last one out of it's place because I didnt' know it existed or why, as there's VERY little information available on the flex fuel pump assembly and it's differences from non flex models. So I reconnected and put the tank back in place to search the interwebs and pirated repair manuals for any information that I could use to make sure I had all the parts needed to not be left up a creek without a truck. Here's a bunch of pics of the info/install I've prettied up and notated for you and hope it supplements @Sumo91 's post and instructions from URD enough to make anyone feel comfortable completing the repair without giving the dealership 1500 for the same damn defective part.

Happy to answer any questions to the best of my memory. Love and thanks for all the help y'all give

 

Great job man! Glad my write up could help you out. You added alot of great info! I used the new sock and just bent it up slightly, it's worked so far, and I've damn near run it empty more than once. But the factory sock is the best choice by far as far as fitment. I don't think it matters which one you use since it's just a pre filter for the pump to keep large chunks from killing the pump.

 

awesome job man. Thanks for detailed pics! I have been trying to find a 38 gallon tank and was planning to do all at same time.

I have a false alcohol reading also. Mines reads close to 90%. LEt me know how yours does after reflash. Wasn't sure if that was a long term fix or if it was a sensor in the tank that goes bad

 

@Jeffro22
From what I understand, the ecu calculates alcohol density of fuel when filling up and how fuel responds to inputs (fuel pump on) compared to other sensors in the exhaust and tells your engine to then run like it's fuel is this % alcohol. Of course if it's wrong, engine runs like dogshit. My decision to focus on the fuel pump as causation was based on the latest TSB (now like 2 years old) now requiring a fuel pump replacement along with the ecu flash and density learning reset.

Can't say with certainty if it will work for everyone, but I haven't seen anyone on here or tundrasolutions that has done all 3 things from the TSB and still had an issue.
I had the ecu reflash prior, but the dealership was very difficult to work with. And I know they didn't relearn alcohol density, so part of me doubts if they even reflashed as they claim. I'll need to ask autozone for their OBD scanner to check what ECU version is installed (vehicle specific version listed in TSB) to verify if it was completed.

I will say immediately after the install, my reading dropped from 85% (where it has been forever) down to 72%, then 53% a few days later and haven't checked since, assuming it continued to correct downwards.

I'll check those this week and let you know, but I'd absolutely do the pumpswap anyways. It's not nearly as difficult as it seems. And if you're upgrading to 38, thought about the larger (46gal) transferflow tank? Wish I had the foresight to have that or 38gal upgrade tank on hand

 

Great write up!!! Just did mine today easy half day job with these instructions.

 

This should be a sticky I'm thinking.....

 

Would like to know how you alcohol density is over the next month or 2. Hopefully this fixed the issue

 

@fytedapowr Thanks for putting this together. I referenced it this weekend. After replacing the stock Delphi with the DW200, it feels like a brand new truck.

 

Op- any update on alcohol density?

 

@68vert glad I could help a few folks out there! Have you scanned your alc density since?

@Jeffro22 I checked with autozones scanner to see if they were able to read my ECU version and they were not, so I dont know still if it's actually been reflashed. And haven't been monitoring alc density often (since it's been driving vastly better) but this morning it was showing 48.5%, so still quite wrong. It's dropped a lot initially, then slowed its curve to tenths of a percent decrease. But its consistent, never reading higher. So there's that

 

I dont think my scanner has the ability to check the alcohol density

 

Following up;
Today was the first cold (50s) morning since new pump. Since most people anecdotally had issues on particularly cold mornings, I wanted to check to see of the alc density would spike.

Great news, no rough start, no weird idling, and alcohol density is closer than ever to accurate

 

The website says these pumps aren't flex fuel compatible is thay true?

 

Some are, some are not. The one I mentioned for sure is.

Follow up: Alc density at 8.9% now. Ecu still not updated yet, but planning on it as I still have 1st gear engagement issues in the cold. All else is great

 

Just had the ECU update 30CK0700 (for a 2012) and the trim and ethanol reset. Filled with E10, ethanol % showed 6% for about 2 minutes, then dropped to 0. I think the latest ECU update looks for a threshold, probably 15% or so, and if it's less than that, forces it to 0. My ethanol was over 60% and major cold start issues prior to the ECU update and resets.

Was told I needed the fuel pump, with a $3500 price tag here in Canada. Just did the ECU update and reset trim and ethanol ($200), and so far so good.

I am using a Veepeak OBDCheck BLE+ Bluetooth 4.0 ($50) with iphone, and the Car Scanner ELM OBD pro app ($10). This tells you the ECU update version, and allows you to monitor everything. Best money I ever spent. Even works to turn off the seatbelt nanny chime.

 

Got mine installed and now I have a random power draw it's been a fun couple days let me tell you I went with the aeromotive 340 and I don't think it's meant for flex fuel I can literally watch my battery drain while running if not on a charger.

 

I have the aeromotive 340 on my flex fuel truck with no issues, I don't run e85 though

 

Did you use the included pigtail to work it in or directly crimp the pump to the top of your fuel pump wires? I find it super hard to belive it draws enough juice to kill my truck in a matter of 10 minutes and the only way the truck will stay running is with a battery tender connected. I've dropped the tank twice checked power to the pump and can keep the truck running as long as I want if the tender is hooked up just trying to figure out if I did something wrong wiring wise.

 

I don't remember there being a pigtail, I believe I just crimped the 2 wires together. Have you tried disconnecting the fuel pump after your battery is charged and seeing if the draw goes away? Seems like the quickest way to rule it out

 

. In my 5th from the bottom photo, you can see how I crimped the wires (red to red, black to white). I can't imagine the difference in draw from different pumps would make any noticeable impact.

Any other changes at the same time? Fuses all check out? Sounds like a job for a multimeter and tracing back from pump to the battery.

 

Thank you for this awesome writeup! I have a 2010 Flex Fuel Sequoia with a faulty fuel level sensor. It will never read past 3/4 full.
Lately I've been noticing sub normal MPGs with a strong gas smell when I floor it and on cold starts. Bought a BT OBD2 dongle and downloaded the Torque app to see what my ETOH content was. I saw 20%+ this morning when I left for work and it dropped down to like 14.9% when I got to work. When I left work, I saw it drop down to 8.6% and it's holding their now. Mind you, my fuel gauge is still showing empty. My low fuel light trips on at about 185 miles into the tank.

Does the ECM use the fuel level sensor to decide when to relearn?

Side note, I read about filling up the gas tank and banging it to try and "unstick" the float/level sensor/sender just earlier and will give it a try. Will bring my sledge hammer along to assist.

 

I've heard your ecu relearns something every couple times you refill the tank, but I couldn't say what it resets or whether there's any accuracy to the claim in general.

It does sound like your float level sensor is either stuck, or stuck against a wall inside the tank. Its the thing with the two blue wires running to it hanging off the outside of the fuel pump assembly. I'd imagine you could solve a majority of your issue with the sensor by disassembling and reassembling carefully to see if it needs replacing or if it just needs to sit in the tank in a different position.

 

Any update? I still haven’t made the swap but want to Do soon. I am having Cold weather start issues and really high alcohol density reading

 

All good still, but another poster started a thread with an admittedly superior and easier solution (assuming your pump is functioning fine). I'll be doing his flex-mod as it bypasses the high-low pressure switch altogether that responds to the ECU's false alc density readings.

I think his mod is absolute genius and fixes some flaws in my thought process. I still think mine is valuable in that a lot of those denso pumps are failing, so you may as well replace with something aftermarket and bypass the donut filter with a serviceable one. But without doing his mod, any increased fuel pressure would be negated by the switch and still relies on the ECU to read well (which I still haven't had a problem with since replacing the pump). Knowing his mod allows the increased pressure from an aftermarket pump and allows the ECU to send whatever readings it wants into a switch that controls nothing is a simpler fail safe for a problem plenty of people have had.

TLDR; do his mod to simply bypass the ECU problem, do mine+his for increased performance and servicability.

https://www.tundras.com/threads/5-7...system-diy-project.101526/page-2#post-2729154

Shoutout @4firemandan !!

 

@fytedapowr

Brotha this is an excellent write up too! It's perfect for someone wanting to upgrade their fuel pump. URD had the old pump upgrade detailed but we had no guide for the new ones. So this is perfect for that! Very detailed.

As you and I both found out the hard way, finding info out there on the FFV fuel system is like hacking into the national archives.

I'm curious, did swapping to a different pump solve your false high ethanol readings?

My experience has been that the tune is what causes this more than anything.

Toyota calculates eth percentage based on Short Term Fuel Trims after a fill up.

High STFT (ie: the O2 sensor reading lean) will cause falsely high ethanol calculations.
It gets a little more complex than that.. There's LTFT as well. So you can't just intentionally run rich to keep ethanol down. I get into that in the HPTuners forum if anyone cares to read up on it I'll post a link.

Anyway, the fuel system upgrade/bypass/mod, or even the VSC relay grounding fixes the low pressure mode for us SC guys, but I would expect to see the same ethanol percentage creep if the tunes off.

How's your truck running now? Any other upgrades yet?

 

@4firemandan

Thanks man! Flexfuel info really is hard to track down, that's why I've got such an affinity to your solution. I'm sure you had to do the same digging I did to find anything helpful.

I don't think I've done anything to this tundra (did on previous 2) in the engine besides the typical K&n air filter and fuel pump upgrade (plenty of suspension mods). The new fuel pump didn't immediately solve the reading, but over time the alc density readings lowered to a more accurate number and stayed there. I've tried different gas stations to see if that has any effect, none observed. I'm thinking my previous denso pump had the impeller problems observed in the fuel pump recalls from a couple years back, so replacing it more or less solved the underlying issue, but I'm still at the mercy of that low/hi pressure switch and the subsequent restricted psi in the lines.

There's a lot I still want to do to the truck (whipple SC, 8112's, DD exhaust, new leafs, sumo springs etc), but first is going to be your low pressure mod.

 

You can get an alcohol reader off eBay/Amazon for like 25 bucks that will tell you exactly what the content is at the station you're filling up.

I usually carry around a Gatorade or water bottle and throw about 8oz of fuel in that. Then test when I get home. (When I was tuning to get an accurate count..I don't really do it anymore)

I actually have a home made tester (60cc syringe) there's a few YouTube videos on doing it yourself too.

This is all of course for the guys that run e85 and different ethanol mixtures but it works the other way too.

I was able to see one station at just under 5% and another at over 10.

 

@fytedapowr
Any reason you went with that specific pump from their options? I'm planning on doing the swap.

 

Not really, it was bigger than stock and probably still oversized for the stock pressure restrictions of the fuel system. Def would advise following @4firemandan instructions to bypass the pressure switch right above the tank/cannister to get better flow

 

Hi @fytedapowr really interesting write up my 2018 has always had the starting problems toyota tells me am not in for ecm update so about 6 months ago i fitted new oem fuel pump worked for a while .truck is reading 83% alcohol .MY question is if i was to block crimp the fuel line coming from the switching valve returning to 43.5 psi regulator in the tank that would mean am getting the higher pressure valve working at the end of the fuel rail. or even wire the switching valve relay into either closed or open. do you think this would help my starting issues. thanks shaun