2000 4Runner needing injectors for 3rd time

[Marcozi]

As the title states, I'm headed towards my third set of injectors in the past year. Last May I threw a code for P0172 (bank too rich). I bought the 4Runner in 2018 with 201k miles on it, and the private seller had put a full set of new injectors in it. When I pulled them out last May, they looked like a cheap set, probably from a box store or Rock Auto; something India made. I can't blame them I guess since they were selling $5k vehicle, and a garage did the work so it was probably out of their control. It now has 251,xxx miles on it.

I use genuine TOYOTA parts from Ourisman Toyota in Richmond VA. In the past couple of years I have replaced:
- TPS
- IAC valve
- all new Denso coils
- Sumitomo plug wire set
- New NGK Plugs
- Cleaned the MAF sensor
- Magniflow cat-back exhaust
- new fuel pump, pick-up tube, sock filter, and sending unit
-the fuel filter back around 2019

Last May when I did the injectors I replaced the valve cover gaskets, PCV valve, fuel pressure regulator, O2 sensors, and the engine looked excellent inside given the mileage. It still doesn't burn oil and there are no signs of coolant issues. I used Motor West Performance injectors for the replacement. The repair went well, it ran great, my MPG went up a bit, and the code went away.

5 months later in October I got a P0172, again, and MWP sent me a new set with new intake plenum/manifold gaskets, and fuel rail banjo bolt seals. Again, the code went away and it ran great. I'm getting quite good at getting the injectors replaced quickly. I'm very careful inserting the new injectors using the provided lubricant, to not cut the o-rings, and also careful to not be sloppy with getting the lubricant where it doesn't belong.

The other day my Runner stumbled a bit at high idle after starting, and it surged a few times on me. I now had a good idea what was happening as this happened the other times as well. Yesterday my LTFT was is at -32.xx% and it actually died on my at my house, but it started right up. The LTFT was in this range the other times as well. If it does through a CEL it has only been for the P0172. Every time after the repair, my STFT and LTFT go back into the -10% to +10% range, and I monitor it for about 2 weeks until I feel confident its fixed. In that time it runs fine, and get 17.5-19.25 MPG.

Am I just having bad luck with "remanufactured" injectors? I know MWP has a good reputation, but I can't come to any other conclusion other than I keep getting injectors from them, and at least one fails after a few months. I know it may not be likely given their reputation, but it's also not impossible, and this is getting OLD. I read on the IH8 Mud forums that Denso fuel injectors are not truely rebuildable because they are a sealed unit. They can be cleaned, screens replaced, replace o-rings, and tested, but they can't replace the solenoids, coils, pintle, return springs, or valves. If this is true, this is a great point and piece of knowledge.

page 2, post #24
https://forum.ih8mud.com/threads/refurbished-fuel-injectors.1225257/page-2


The reason I believe that its a bad fuel injector, and at this point not another issue, is that new injectors always fix it with no lingering problems. I would think that if its related to the ECM, bad wiring, or bad Toyota fuel system replacement parts, the issue would persist immediately, even after new injectors. All the other data from the IAT sensor, MAF sensor, TPS sensor, Coolant Temp sensor, and 02 sensors are correct and with in a healthy range.

I would like some thoughts on this. MWP has a Million Mile/Lifetime warranty on their injectors for the 5VZFE, but I'm very tempted to just get a new set of genuine Toyota Denso injectors from Oursiman Toyota at $166/each, and hopefully be done with this. Yota Shop has Aisin injectors that are claimed to be new OEM (I know Aisin makes good stuff) for a much cheaper $89.37/each, but I'm wondering if I need to stop cheaping out on this, bite the bullet, and just go new Toyota injectors. If this happened again after doing so, I would be confident that there is another issue. I just don't know what that might be if a new set of injectors always solves the issue.

For fun and general interest, I've attached a few photos of what the heads look like once the covers removed; I was happy with what I saw. I'm liking Valvoline in our Yotas, and I'm currently running the Restore & Protect.

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Try this company. https://www.rcfuelinjection.com/

 

[Goodkat]

Try this company. https://www.rcfuelinjection.com/

Thanks for the reply and suggestion, but i just ordered a whole new set and the necessary gaskets this morning.

 

[Goodkat]

Those brown injectors are known problem-children. A good rust free 4Runner of this era is bringing a kings ransom, at least they are where I live. Easy for me to say but I'd bite the pillow and buy new Toyota injectors and be done with it, this particular vehicle is worth it.

Those brown ones were the replacements the seller had installed. I tried looking up the name, it was something like "Aaraan". It's not good when a lot of sketchy Temu type ads and sites pop up for the brand name.

Bite the pillow indeed. $1,146.00 after tax and shipping for everything I need. Hopefully WMP gives me something of refund, or a new set to sell.

 

[Ranger83]

It's a 2000 4Runner. And high mileage. How much do you want to spend? Get injectors from Trav.

Have you checked the frame for rust issues? My brother had to junk his 2004 4Runner as the mechanic would not put it on a lift due to extensive rusting. I think there were class action law suits due to the Dana frame.

The recall was for Tacomas. The 4Runner frame was made in Japan.

They still rust. Ours (2001 with 151,000) was rusted on the inside of the frame next to the fuel tank. Costly repair. Many of the used trucks I looked at had frame repairs.

We use OEM for a lot of stuff (like lower ball joints) but haven’t had to replace the injectors yet.

 

[02SE]

Why would a company come up with and sell a frame repair kit designed for several models of the 4Runner if there was not a problem?

Look at autorust.com.

Because they saw a market for owners of neglected 4Runners.

I owned a 3rd gen 4Runner for 22+ years. It was operated every winter on Salt encrusted roads, and spent time every year on the Bonneville Salt Flats. When I sold it, it was rust free. How? I washed the Salt off (including the undercarriage) regularly.

The day I sold it doing an in-and-out through a dealership.

I recall a neighbor who bought a Mercury Mountaineer (Ford Explorer) at the same time I bought my 4Runner. After 10 years, his Mountaineer was a rusty hulk, it's frame and body were ready for the scrap yard. In fact it was scraped. It had also had many major mechanical repairs. My 4Runner in over double the years of service, had only needed a $20.00 hydraulic hose, and an hour of my time to replace.

A 4Runner is very reliable mechanically, but if Salt isn't cleaned off while operating in a highly corrosive environment, eventually that neglect can lead to frame issues, as it can for every other brand. But those other brands aren't typically as reliable, so they get scraped sooner. I saw it regularly when I worked in a repair shop that worked on all brands.

 

[D60]

Here's a '96 with 526k miles on my lift right now. I dunno if this proves much because things don't rust much in SW Colo (even when it's snowing the air is dry)

 

[Goodkat]

Here's a '96 with 526k miles on my lift right now. I dunno if this proves much because things don't rust much in SW Colo (even when it's snowing the air is dry)View attachment 268653View attachment 268654

I bought mine from a guy in Wisconsin, who inherited it from his mother who was a realtor in Colorado. I found a business card from Durango the first time I detailed it.

I'm from Michigan where they use plenty of salt all winter, and winter is long. Every Fall I would coat the underside of our vehicles with Fluid Film. A couple of times a month I would spray our cars off on warm days, and then spray WD40 in the wheel-wells and kick panels. This process worked pretty well and kept new rust to a minimum.

Being in Virginia now, the winters aren't nearly as bad and neither is the salt usage. I have some mild surface rust that I want to touch up over the summer. Hopefully, I won't be replacing fuel injectors this summer...

 

[D60]

I bought mine from a guy in Wisconsin, who inherited it from his mother who was a realtor in Colorado. I found a business card from Durango the first time I detailed it.

I'm from Michigan where they use plenty of salt all winter, and winter is long. Every Fall I would coat the underside of our vehicles with Fluid Film. A couple of times a month I would spray our cars off on warm days, and then spray WD40 in the wheel-wells and kick panels. This process worked pretty well and kept new rust to a minimum.

Being in Virginia now, the winters aren't nearly as bad and neither is the salt usage. I have some mild surface rust that I want to touch up over the summer. Hopefully, I won't be replacing fuel injectors this summer...

Interesting, I wonder if you got the scary airbox warning this one did? Warning! YoUR cAr haS ComPOoTerS!!

 

[Goodkat]

Interesting, I wonder if you got the scary airbox warning this one did? Warning! YoUR cAr haS ComPOoTerS!!View attachment 268668

Nope! Didn't have that, or the dreaded K&N sticker. Yours looks solid still, and congrats on the half million mileage; impressive! The Gen 3 4Runner is the first vehicle that I ever considered buying used at 200k miles. It's also the vehicle that got me i to liking Toyotas almost twenty years ago. High mileage is different for these than most other vehicles.

 

[notharry]

Im another for not using much reman anymore. I have had good luck with Advance auto starters, but their calipers rebuild units stick. I had one blow out the seal and leak everywhere while pushing the piston back when I suspected it was binding. They look beautiful. I suspect poor quality rubber parts swelling up. I get that they don't make a ton of money on rebuilding things. But why bother if it's not done right? It must be that 1/2 of the people that buy these parts just give up and eat the decision. Like with these calipers that were in 10 months. I just wanted to buy new at that point because the chances are I will be doing them again in... Follow me here. Take a guess. You guess correctly! 10 months. Is that cost effective for me a DYI guy? Or worse, You the guy trying to feed their children. Nope. Someone needs to say no. Say no to reman electric injectors. Even if they can get them apart, how good are the new seals and rebuild parts? Mechanical ones sure because as said they can get them apart. Area diesel does a great job in this realm.

 

[The motor guy]

And somehow all 8 factory injectors on my two old trucks are still perfect, one with 269k and the other 341k. But those old injectors which i think are delphi or bosch must be better than the new ones. I don't think the new ones would last that long anymore. Quality of everything has gone down for the most part.

It'd have to be bad luck if everything else is measuring ok. I doubt the computer is misreporting numbers.

I've never heard of needing injectors replaced on a gas engine.

 

[zzyzzx]

I'm wondering about the wiring to the injectors, especially the last few inches as you get close to the connector that plugs into the injector.

 

[The motor guy]

I've never heard of needing injectors replaced on a gas engine.

I mean unless it's a boat that's sat for a year, but not a car that gets driven all the time

 

[notharry]

Why do injectors fail? Electrical issues and mechanical issues.
Electrical issues. Opens and shorts. Why. Over current. undercurrent. Mosture. Heat. Have any of these?
Mechanical issues. Sticking. Stuck, Clogged, leaking
Poor fuel quality, Sitting lengths of time. Poor maintenance. Fuel line deteriation. Moisture. Internal seals
Does your vehicle have a replaceable fuel filter change it a regular intervals. Run fuel system cleaner once in a while in your fuel. Techron is a good one. You dont need to run premium fuel unless required my the MFG. Get your fuel from a reputable busy station. I only replaced fuel injectors in 3 in all my DIY years. 2 were GM "spider" types on the GM 4.3 Vortec as the seals blew out and the other was a subaru and I was guessing. It ran the same. I maintain 4 vehicles for myself and family. One time a injector connector was corroded and 2 mechanics replaced everything else but the connector! I did it myself with a junk yard one.
Yes things wear out eventually.