Refurbished Fuel Injectors?

[MJK]

I've used RC Engineering for OEM injector refurbishment before. The car was 10-12 years old and RC reported 4/6 as good and 2/6 as fair before their corrections. It sounds like FIS does something similar at half the price, which is a smoking deal. I'd do that any day before getting new injectors of unknown quality.

In our stock application, it seems to me that most of the benefit of new or cleaned injectors is simply in ensuring that all are atomizing fuel as designed regardless of how many holes they have. I have no idea how common injector fouling is or isn't on these trucks. Does anyone else? Maybe a pre-clean / post clean report or something at XXX,XXX miles?

I've heard of DIY bench testers built with a pressurized fuel/cleaner source and one of these, which I find interesting. I doubt it makes sense to build one for one time personal use compared to an FIS service, but it would be interesting to see if something like the photo below is commonplace or extreme worst case. And, how much of an impact correcting that does for your MPG, power, cat temperature, etc.

 

[ClassyJalopy]

I will be soon looking to make a decision about getting my injectors serviced or replaced just as a matter of course.

The going price for a quality injector service job ranges from $25 to $30 each. The company should provide new screens, o-rings, pintle caps, and provide a flow testing report.

I need to decide in the next few months if I will get my existing injectors serviced or to buy new ones. I need to do more research in this area for a 2UZ.

Are you convinced your injectors are bad because the truck is running rich? There could be other problems at play.

You guys are amazing! Thanks for sharing your experience with the duds and the insights on how to identify good quality ones.
I understand the aftermarket knock offs are absolute garbage but what about quality refurbished Denso injectors? Wouldn't it be the same as getting my own injectors serviced?

 

[JunkCrzr89]

I understand the aftermarket knock offs are absolute garbage but what about quality refurbished Denso injectors? Wouldn't it be the same as getting my own injectors serviced?

Maybe, maybe not. Depends on the quality and steps of refurbishment that were used to produce a “refurbished” Denso injector.

 

[OwnerCS]

You guys are amazing! Thanks for sharing your experience with the duds and the insights on how to identify good quality ones.
I understand the aftermarket knock offs are absolute garbage but what about quality refurbished Denso injectors? Wouldn't it be the same as getting my own injectors serviced?

This is just an observation and suspicion. There are thousands of refurbished Denso injectors on market. Possibly more remanufactured than initially manufactured. It just looks suspicious. In another car club, we found the remanufactured injectors on eBay were actually new China injectors being sold as remanufactured OEM.

If I cannot get my old injectors serviced, then I will buy new Intermotor injectors from Rock Auto that are reboxed OEM directly from Denso/Aisan with all of the correct quality lot numbers..

There are a number of injector service companies that are misleading consumers.

There is there is no way to remanufacture a Denso injector. It is a sealed unit. The moving parts cannot be replaced.

Injectors can be cleaned, have new screens installed, new o-rings, and tested. That's it.

To anybody that says they are remanufacturing Denso injectors, ask them how they are replacing the injector solenoids, coils, pintle return springs, and valves.

 

[ClassyJalopy]

I am getting a set of known-good set of fuel injectors from a fellow 100 series owner. They will go straight to a injector service shop and hopefully I will end up with minty fresh serviced injectors without an extended down time.

 

[suprarx7nut]

We have data showing the difference for retrofitting 12 vs 4 hole in the VVT 2UZ is very, very small, if it exists at all. Data shows that it does not exist or that the difference is smaller than the level of noise in other variables.

We know the difference between genuine and fake injectors is potentially catastrophic and we know it can be very difficult to ensure your injectors are genuine if not bought directly from Denso, Toyota or Lexus, even if they're flow tested.

My input is to ONLY use genuine OEM injectors sold directly by Denso, Toyota or Lexus. If you don't want to pay for brand new genuine injectors (12 hole or 4 hole), have your existing genuine injectors cleaned by a professional shop.

Cheap aftermarket injectors (<$400) are not a gamble worth taking, IMO.

 

[ClassyJalopy]

Fuel Injector Specialist in Wheaton, CO is the shop I am planning to send my set to for service. I think that shop is also recommended by @2001LC

Home

Company Name - Wheat Ridge, CO. Company Message

www.fuelinjectorspecialists.com

 

[JunkCrzr89]

Fuel Injector Specialist in Wheaton, CO is the shop I am planning to send my set to for service. I think that shop is also recommended by @2001LC

Home

Company Name - Wheat Ridge, CO. Company Message

www.fuelinjectorspecialists.com

Chuck is great. You won’t be disappointed and his prices are unbeatable!

 

[suprarx7nut]

Fuel Injector Specialist in Wheaton, CO is the shop I am planning to send my set to for service. I think that shop is also recommended by @2001LC

Home

Company Name - Wheat Ridge, CO. Company Message

www.fuelinjectorspecialists.com

Chuck is great. You won’t be disappointed and his prices are unbeatable!

That's who I used as well. Pricing is great, service is great. He'll even send pictures of the spray patterns. My spray volumes were good, but spray pattern was funny on one prior to cleaning.

 

[KFunk740]

I bought all 8 rebuilt injectors (Autoline) from RockAuto for $26 each + $10 core; so I wouldn't have to have any downtime while sending for rebuild. My plan was to just keep my original Densos and send them off for rebuild from a reputable company in my own time while.

But the RockAuto ones have worked fine, no issues at all. I've gotten over 16MPG with mostly highway in my '99. I think I'll just hang onto the original injectors and leave them on the shelf forever.

 

[MJK]

Bumping this up, as some recent experience with an old Honda of mine put @ClassyJalopy 's original post back in my mind.

Start with P01710 = truck thinks it is running too lean. So, presumably it tries to correct by adding fuel.

If that determination was in error, it seems like that might cause some of the other symptoms described. Have you checked the O2 sensors and/or Fuel trims?

Or, perhaps temperature related? Stuck thermostat = actually running too cool. Faulty/dirty IAT sensor = think the air is cooler denser than it really is?

When you pulled the old plugs, how did they look?

 

[ClassyJalopy]

Bumping this up, as some recent experience with an old Honda of mine put @ClassyJalopy 's original post back in my mind.

Start with P01710 = truck thinks it is running too lean. So, presumably it tries to correct by adding fuel.

If that determination was in error, it seems like that might cause some of the other symptoms described. Have you checked the O2 sensors and/or Fuel trims?

Or, perhaps temperature related? Stuck thermostat = actually running too cool. Faulty/dirty IAT sensor = think the air is cooler denser than it really is?

When you pulled the old plugs, how did they look?

I have yet to check the fuel trims with TechStream. Thermostat has about 25k miles on it so I don't think it is the issue. The spark plugs came out looking pretty decent no white or black or oily electrodes.
Now, I haven't messed with the IAT, is that intake air temp sensor? where is it located?

 

[ramangain]

No idea. Science says 12 holes is ineffective, and may actually result in even worse emissions. Most studies indicate 4-8 holes are optimal for emissions, with little to no (negligible) improvement beyond 8 holes. From Lee et al. (2010; International Journal of Automotive Technology, 11: 783-791), “The results show that increasing the number of holes significantly influences evaporation, atomization, and combustion. However, when the number of holes exceeds a certain threshold (>8 holes), there is an adverse effect on combustion and emissions due to a lack of the air entrainment required for the achievement of a stoichiometric mixture.”

NICE cite!!!

The publishing scientist in me just jumped for joy

 

[ramangain]

Bumping this up, as some recent experience with an old Honda of mine put @ClassyJalopy 's original post back in my mind.

Start with P01710 = truck thinks it is running too lean. So, presumably it tries to correct by adding fuel.

If that determination was in error, it seems like that might cause some of the other symptoms described. Have you checked the O2 sensors and/or Fuel trims?

Or, perhaps temperature related? Stuck thermostat = actually running too cool. Faulty/dirty IAT sensor = think the air is cooler denser than it really is?

When you pulled the old plugs, how did they look?

*cough* Acura *cough*

 

[MJK]

I have yet to check the fuel trims with TechStream. Thermostat has about 25k miles on it so I don't think it is the issue. The spark plugs came out looking pretty decent no white or black or oily electrodes.
Now, I haven't messed with the IAT, is that intake air temp sensor? where is it located?

My IAT (intake air temp) comment related to my rich running "Honda". Apologies for not making that more clear. I'm 20 years into ownership of that, vs 6 months for the 100. So, take any advice from me on this topic with a kilo of salt. I think the MAF/MAP serves this function on the 100.

The point I was trying to make, poorly, was that perhaps the issues (heat, MPG, Code) could be a symptom of a larger problem to the truck's ability to properly control A/F ratio. If for some reason the truck was overfuelling, it seems like that might explain a lot. Just by gut feel, the injectors wouldn't be the first place I looked.

Other things in my (non-100 specific) experience that might commonly cause this include:
MAF/MAP sensor - NGK/NTK is $100
Primary O2 sensors - Denso are $40 ea
Truck running too cold, or thinking it was. Temp sensor/thermostats are $30 ea.
Exhaust leaks upstream of the cat - ?
Air intake leaks, or PCV?

If the plugs don't indicate rich running, this while theory could be red herring. But I would still check the fuel trims.

Hopefully someone who knows these trucks better than me will chime in and we can all learn something.

 

[JunkCrzr89]

My IAT (intake air temp) comment related to my rich running "Honda". Apologies for not making that more clear. I'm 20 years into ownership of that, vs 6 months for the 100. So, take any advice from me on this topic with a kilo of salt. I think the MAF/MAP serves this function on the 100.

The point I was trying to make, poorly, was that perhaps the issues (heat, MPG, Code) could be a symptom of a larger problem to the truck's ability to properly control A/F ratio. If for some reason the truck was overfuelling, it seems like that might explain a lot. Just by gut feel, the injectors wouldn't be the first place I looked.

Other things in my (non-100 specific) experience that might commonly cause this include:
MAF/MAP sensor - NGK/NTK is $100
Primary O2 sensors - Denso are $40 ea
Truck running too cold, or thinking it was. Temp sensor/thermostats are $30 ea.
Exhaust leaks upstream of the cat - ?
Air intake leaks, or PCV?

If the plugs don't indicate rich running, this while theory could be red herring. But I would still check the fuel trims.

Hopefully someone who knows these trucks better than me will chime in and we can all learn something.

I generally agree with @MJK post above. Specific to @ClassyJalopy intermittent P0171, I’m curious if you’ve implemented Toyota’s diagnostic troubleshooting procedures http://4runnerclub.com/i/4r_files/f...7toyrm/07toypdf/07rmsour/4runnerr/0060028.pdf ? Based on your OP, it sounds like you’ve probably ruled out about 5-6 of the 12 things that could cause P0171. How old is your fuel pump? From my experience with 100 and other Toyota 4x4s, intermittent P0171 is often (but not always) an early warning sign of a failing fuel pump.

 

[MJK]

^^^ Interesting read. Thanks for posting.

It seems by definition anything that causes a +35% fuel trim on Bank 1 throws a P0171. Bank 2 would be a P0174.

My theory was that the A/F was reading artificially lean, and therefore adjusting trim to be too rich and causing some of the other symptoms. This still sounds like a reasonable hypothesis, but it is curious that only Bank 1 throws the code.

If the A/F ratio was correctly reading bank 1 as too lean, and correcting back to normal A/F it sounds like you'd get the same code. Fuel pressure issue maybe, but again I can't think of why it would only be Bank 1.

It would be very interesting to pull trims for both banks. If trim for Bank 2 is substantially different than Bank 1, I would think that rules out both fuel pump and MAP/MAF sensor. If they are both boosted a bunch, an exhaust leak/cracked manifold or single O2 sensor failure seems unlikely.

 

[2001LC]

I bought all 8 rebuilt injectors (Autoline) from RockAuto for $26 each + $10 core; so I wouldn't have to have any downtime while sending for rebuild. My plan was to just keep my original Densos and send them off for rebuild from a reputable company in my own time while.

But the RockAuto ones have worked fine, no issues at all. I've gotten over 16MPG with mostly highway in my '99. I think I'll just hang onto the original injectors and leave them on the shelf forever.

Tip: Storage of fuel injector.

Denso coats with "some oil" that prevents needle from rusting. Those can sit in the box forever, and work fine every time. Once cleaned or used (gasoline washed), needle may rust.

Storage of fuel injector:
New Denso in the box. No special requirement.
Non Denso new in the box. Have rebuilt (cleaned and tested) before use.
Used fuel injectors or rebuilt. Store in fine oil. I pack in jar filled with M1 ATF.

 

[ClassyJalopy]

I generally agree with @MJK post above. Specific to @ClassyJalopy intermittent P0171, I’m curious if you’ve implemented Toyota’s diagnostic troubleshooting procedures http://4runnerclub.com/i/4r_files/f...7toyrm/07toypdf/07rmsour/4runnerr/0060028.pdf ? Based on your OP, it sounds like you’ve probably ruled out about 5-6 of the 12 things that could cause P0171. How old is your fuel pump? From my experience with 100 and other Toyota 4x4s, intermittent P0171 is often (but not always) an early warning sign of a failing fuel pump.

Thanks for sharing this. I will take a look.
My fuel pump has roughly 50K miles on it.

 

[ClassyJalopy]

So about a month later I still haven't looked at the fuel trims and went on a 2000+ miles trip with p0171 still triggering the CEL !
I am far from home and finding my truck some times misfiring at low RPM when under load

I am heavily laden with 5 passengers and their stuff, so going uphill at highway speeds and starting off from a red light pronounces the misfire even more.

With no easy access to techstream what are my options for diagnosing this? I do have ELM327 wireless scanner with me. So I can read codes but that's abt it