MIsfire on Cylinders 2, 4, 6 after replacing injectors 1, 3, 5 adn fuel filter

All of the OEM injectors are gone. I am going to just drive it around and watch it closely. Like I said, despite the codes, it seems to run fine, though again, the idle is a bit bumpy and low sometimes.

 

The 3.4L is single bank fuel control (one upstream AFR sensor), all of the injector pulse widths are controlled together unlike engines like the 4.0L that have dual bank control (2 upstream AFR sensors) that can control each bank of injectors independently.

So if you have injectors on one bank that have a different flow rate than the ones on the other bank and the PCM is trying to maintain the proper air/fuel ratio by lengthening or shortening injector pulse width your going to have misfires on one bank because it's only seeing the total air/fuel ratio of the whole engine and going by that.

Granted the only way to test this is by doing an injector balance test using a fuel pressure gauge and a tool that pulses the injectors but it just seems like too much of a coincidence that you had a single cylinder misfire, you put Amazon injectors in, and now you have a 3 cylinder misfire.

I recently dealt with this on a Ford 5.4, the guy had just bought it and it had misfires on one bank. Saw that bank had 4 new injectors in it, did an injector balance test on it and they were flowing way different then the other bank that had original injectors. Put 4 new SMP injectors from the parts store in it and it ran great.
Looked up the number that was stamped in the questionable injectors and yea they were amazon/ebay specials

Misfire counters aren't always 100% accurate especially when you have a multiple cylinder misfire.

 

They changed injector for the 3.4 about mid-make.
And I think they did flow different too.

I am pretty sure I seen it here on TW.
I’ll see if I can find it.

 

@Dm93

Here it is
https://www.tacomaworld.com/threads...98-vs-1999-3-4l-engines.606511/#post-20468760

 

I mean if you have injectors with x flow rate in one bank and ones with a different flow rate in the other bank on an engine that as far as the PCM is concerned only has one bank your gona have misfires, won't be a hard miss but it's not gona run right.

I could be totally wrong but have absolutely zero confidence in cheap parts from Amazon/ebay (including the "OEM" stuff that is somehow half the price of actual OEM), I've had to fix so many problems caused by that stuff I just tell people don't buy vehicle parts from amazon/ebay. Sure there's some legit stuff on there but there's far more crap on there and it's hard to know if what your buying is legit or a cheap knockoff, it's bad enough with parts store parts anymore to get anything that's worth a crap.

Umm yea 6 injectors for $65....seems legit

$66 JDMON Compatible with Fuel injectors Toyota 4Runner Tacoma Tundra 3.4L V6 1999-2004 Replace 2320962040 2172933 2 Hole Pack of 6

https://www.amazon.com/JDMON-Compatible-injectors-1999-2004-2320962040/dp/B087CY783N/

 

Looks like a good way to spend $65 and do the job twice.

 

OK, so will the PCM be able to reconcile this with time? I bought a complete set of 6 injectors, and since the other side was OK, and there was no reason to pull the intake, and did not give it any thought.

Should replace the driver side, the one with the reported misfires, with the other 3 new ones I got? I don't really want to, but if that is in fact the issue I will.

 

It’s never a good idea to replace one injector. Ideally you’d like to replace them all.
It’s even worse of an idea to use cheap aftermarket injectors.

I would have replaced all 6 when you did them. I mean, why not?

 

While I agree 100%, my wallet disagreed. I did not just replace one, though, I replaced all three on the passenger side. I know better than to use cheap parts, but money being what it is right now. It is what it is.

So since I have the other three cheapy injectors, should I just use them them on the driver side?

 

I mean if they aren't correct no.
Would changing all of them make it run better, possibly depending on how close to the factory injectors they are but don't be surprised if the fuel trims aren't happy.

 

I mean I wish parts were cheaper too but quality parts just aren't, even alot of the not so quality stuff isn't cheap anymore.

 

1 or 3, it doesn't matter.
It's all or none unless the injectors are "relatively new"

Can you replace 1, 2, 3......?
Sure. But you are usually just buying time until the others fail, or you create a problem. Like in your case.

 

Did you disconnect the battery in the midst of turning off the CEL? I do nowadays if it's something the computer has been working around for some time.

 

I did disconnect the battery, was thinking about doing it again to reset everything. Worth a try I guess.

 

Excellent, excellent information… did not know this about the injectors… bank fire. This makes sense now.

 

Not exactly, bank fire would be multiport injection (injectors all fire at the same time).
The 3.4L is sequential injection (the injectors are fired one at a time).

I was saying they are all 6 pulsed for the same number of milliseconds when they fire where an engine that has individual bank fuel control can adjust the pulse width of each bank of the engine individually based on O2 sensor feedback if that makes sense.

 

Coming back for a follow up here. As I already knew, and it was mentioned a few times, do not buy cheap injectors! I ended up buying new OEM injectors and basically got my money back on the cheap ones from turning in the cheap ones for the core. There was not one good review on Amazon about thee injectors, so definitely lesson learned.

While I was doing the job I thoroughly cleaned the Throttle body and IACV. Now I am having some difficulty getting the idle to reset completely reset so there is some fluctuation in the idle. (I had disconnected the battery while doing the work to reset any codes that I knew it had to see if they would come back. I tried all of the tricks on youtube with turning the ignition on, off, then on again after warming it up, and sitting in gear for 5-10 minutes and that is supposed to "reset" the idle. This did not work for me and I have tried it many times. I did see one that said turn the ignition on, press the gas pedal and hold three times, then start and that seems to have mostly resolved it, though while driving at low speed I can still feel it surging a bit.

Do I just need to drive it and get some miles on it?

 

Have you checked for vacuum leaks? That can cause an idle surge.

 

I did. The air intake tube was way more cracked than I realized. Even though while spraying brake cleaner around the area while running and getting no change, it was cracked pretty far back.

I ordered a new one and it should be here tomorrow so we will see if that resolves it.