Bad injector?

My 99 Tacoma 3.4l has been misfiring really randomly. Finally got a check engine light for a code P0304 which is cylinder 4 misfire. Figured it was the coil since plugs and wires have been replaced. Went to the dealer for the part and they recommend a diagnostics check for free, why not. They switched the plugs, coils, and wires and did not fix the misfire. So they think it’s a bad injector, but it’s gonna cost 500$ for them to switch injectors just to see if it’s faulty, if so another couple hundred for them to actually replace it if it’s just one... my question is if the injector is bad would it not be acting up constantly, not randomly. Because if it was clogged then it would always misfire, correct? Must be electrical, just don’t want to waste a bunch of money at the dealer.

 

Damn $500 do you have tools to swap it yourself? I would try it myself if i had to. $500 is alot of mula

 

Yes do you know what all I have to take off to get to them

 

Very common, you have to remove the two intake halves to get to the injectors. It's not too bad but consider new orings for all injectors as when you remove one, you remove 3 at a time.

 

Should I replace all 6 while I’m in there? And where should I get them because the dealer wants 120$ a piece I believe.

 

Id swap the injector first, that way you know its not a dead cylinder or wiring etc.

 

Gotcha I’ll pick it up tomorrow and do that

 

Here's the guide I followed when replacing my injectors. Also, I got all Carquest injectors and they were $42/each +$9 core charge/each. So it cost about $300 to replace all 6 injectors myself. Good luck

 

If you end up needing injectors, I've heard decent reviews from motor West performance for injector cleaning or their replacements.

 

If you do replace the injectors make sure you get them from someplace legit. They're are a lot of Chinese fakes floating around posing as OEM/Denso, especially online. Cheap injectors are not worth the headache they'll cause

 

Yeah like the ones on eBay that are 60$ for all 6. Definitely not denso

 

Yeah lol

 

Yes. Recommend you do them all at the same time. You want them to flow at the same rate, and also not to do the work twice when the rest start failing. Motorwest Performance flow matches their injectors.

 

I suggest just sending your fuel injectors off to be serviced. Injectors really aren't rebuildable, the remans are just used injectors that have been ultrasonically cleaned, flow tested and fitted with new o-rings/filter baskets/pintle caps - same as would be done if you send yours to be serviced, except sending yours in is typically much cheaper. Motor West seems to be popular and they charge $20 per injector.

 

Definetley going to have to do that. Only bad part is how long that is going to take, I'll give them a call today.

 

verify its the injector first as mentioned. Swap the bad one with a good one, reset the code, and see if the code follows. There's other things that could cause the missfire, and u want to know if it is them instead. I went thru the same

 

If its still misfiring in the same spot even with the newly swapped injector you can do a compression test on the motor i think the compression should be 127-170 psi

 

There are SO many fake injectors out there.

Send them to motor west in California and they will rebuild them (6) for 125 and turn around time is 4 days.

They come with new O rings too

 

I've been debating on this or a set of their upgraded denso injectors. $100 though.

 

Well when toyota put everything back together the misfire dissapeared! So for now I am crossing my fingers that it does not come back.