Injector Difference 1998 vs. 1999 3.4L Engines

This afternoon I pulled the injectors out of the replacement engine. I purchased a kit to refurbish injectors for the 1999 model. Based on the kit contents I felt comfortable with the 1999 model style injector.

When I pulled the 1998 model injectors, here's what I found in the picture below.

Are the lower intake manifold, injector rail, and other fuel delivery parts different between a 1998 and 1999 model?

These look like the injectors that you will find on a 21-year-old engine. They need professional servicing.




Here's a picture of a 1999 model injector.

 

They made two different injectors for the Tacoma.

The early style which went up to 1999 I think.

The latter style 1999- 2004 up is a much better injector and has a larger flow then the early injectors.

I’m not 100 percent when the newer style was switched to.

Some of the newer injectors style needed an adapter for the wiring harness and some seem to plug and
play with a little Manipulation.

You definitely want the newer injectors if possible

 

I agree. I don't see any mention of rail or intake differences so far. But I have found a mention of where the 1999-2005 (Phase II)
injectors have a better spray pattern. I guess I can order one of the Phase II injectors and measure it to see if it has the same physical size.

I would like to keep the rails and intake manifold with the 1998 model engine.

 

Im pretty sure they are all the same just injector are different, yes better spray pattern and they flow more fuel

 

Looks like I'm going to be into is for $55 each if I want to get some Intermotor FJ585s. The only China injectors I would have are roughly $17 each and it takes a month to get them. Then I would need to send them to FL for flow testing before I would bother with installing them.

 

Picked up some new FJ585 knock offs from Amazon for $78 on closeout for a set of six. I'll send them to Florida and get them tested for $7 each. If they survive the test, that will put me in under $20 each. I can still refurbish my old ones and just keep them around.

I've used this company in FL for other projects. Reasonable pricing and service.

http://www.proflowtech.com/

 

DENSO has a certain type harness plug in I believe so make sure they are compatible

 

For sure. I will be staying with my 1999 model harness and plugs.

 

Some videos on how to clean and refurbish injectors.

https://www.youtube.com/watch?v=4l0Fk4xI2y0

https://www.youtube.com/watch?v=vyVHW87mzlo

https://www.youtube.com/watch?v=V2sD5UsOnJs

https://www.youtube.com/watch?v=LQ44_QyoXiM

 

It's been a while but I put a 2002 motor in my 96. I called URD and talked to Gadget and he said all 3.4l injectors are the same; They switched manufacturers at some point which is why the later ones have a different part number.

I've ran the 2002 injectors for over 20k miles without issue. They plugged into the engine harness for my 96.

 

Good news @Wulf . Thanks for the update.

 

Same as @Wulf I put a 2000 engine in my 98 and the connectors were the same.

 

Yes I have spoke to Gadget in the past about this and he told me the same; all 3.4L 5VZ injectors are the same, 240cc.

https://www.customtacos.com/forum/1...uestion-3-4-5vz-fe-tacoma-4runner-tundra.html

 

Did the EGR change between 1998 and 1999 models?

I don't see an EGR on the 1998 4Runner and the part is not listed for that engine. When I look up an EGR for a 1999 Tacoma, it lists it for 1995-1998 models.

If this Tacoma doesn't have an EGR tube to get clogged up, I'm happy.

 

Barely any 5vz engines Tacomas have egr and they tend to be pre 98.

 

Thank you. Good news. I've cleaned enough clogged EGR tubes for a lifetime.

 

I don’t know if you can still find the thread, but on toyotanation they posted a minitruckin article about using Bosch injectors on n/a and boosted and the spray pattern was very atomized and gave gains that were worth it. You would need pigtail adapters to run em, just a thought.

 

Good to know. The FJ585 style injectors that I ordered from Amazon will arrive tomorrow. I'm going to check them out closely and send them off to FL for testing. If they don't work out, then I will look into this.

 

There is a difference regardless what Gadget says in flow rate on the early 3.4 fuel injectors, it’s not much, I do remember reading the different numbers somewhere from 230 for the 1996-98 or something to 240-250.
Because it’s a small change probably is referred to as the same but when superchargered it made a little difference.

This guy actually did a flow rate on the two types and the early style shown 230 flow and the newer style 248.

I definitely noticed a difference with the supercharger with less pinging with the newer injectors before
I went to the methonal.

So they did change the flow rate just a little for some reason and the droplet size is probably better with the newer injectors, better spray pattern.
DENSO was also making a lot of upgrades right in these years (1996-2002) to their Fuel injectors too

 

That last visual explains it all!

I looked at the videos about cleaning injectors - all very good info. Unfortunately, for me, one of my injectors had too high a value of resistance (24 ohms, should be around 14-15 ohms).