Injector seal confusion

[E.Murray]

We bought a 2007 with a blown engine that the PO had partially disassembled. Will be re-assembling this weekend and came across a question on the injectors. I did some research on here a while back and found that the Toyota seals seem to be the jewel for these. So I ordered them.

Then I went and looked at the injectors (got them in a big box o' parts. They were still in the fuel rail). I see two seals on there. There's one thin (and broken) one at the top, then a fat blue o-ring. That's it. Neither of them look like the Toyota part. I looked on Edge and they show three seals, but nothing tells me where they go. So I went to the dealership to get a schematic. He shows a total of 5 seals. Four in the top and one on the bottom. And he wanted almost $300 for new ones. My guess is that this Toyota one goes on the bottom. Is that right? Also, am I really missing that many seals? And do I have to get them from the dealership?

I've searched on here, but people just talk about the "injector seal" like it's one part. How many are there and do I need to buy all new ones?

[stockms3]

Originally Posted by E.Murray We bought a 2007 with a blown engine that the PO had partially disassembled. Will be re-assembling this weekend and came across a question on the injectors. I did some research on here a while back and found that the Toyota seals seem to be the jewel for these. So I ordered them. Then I went and looked at the injectors (got them in a big box o' parts. They were still in the fuel rail). I see two seals on there. There's one thin (and broken) one at the top, then a fat blue o-ring. That's it. Neither of them look like the Toyota part. I looked on Edge and they show three seals, but nothing tells me where they go. So I went to the dealership to get a schematic. He shows a total of 5 seals. Four in the top and one on the bottom. And he wanted almost $300 for new ones. My guess is that this Toyota one goes on the bottom. Is that right? Also, am I really missing that many seals? And do I have to get them from the dealership? I've searched on here, but people just talk about the "injector seal" like it's one part. How many are there and do I need to buy all new ones?

When we talk about injector seals we talk about seals directly between the head and the injector. Toyota seals look different than the Tokay(corksport now?) seals because it is a different design. Some reported leaks with toyota seals, but I run em just fine for now. No need to replace any other seals unless they are cracked or something.

[E.Murray]

Thanks. Good to have confirmed.
So how many should there be at the top of the injector? I only see 2 but the Mazda schematic shows 4.

[Djohns]

Toyota seals are a cheap temporary fix in my opinion. I’d opt for CS for long run purposes.

[aackthpt]

If it's on the parts diagram, there are that many.
https://www.jimellismazdaparts.com/i...ze/4B17421.jpg
though from the names one is an 'o' ring, and three are called "grommet".

I added all 4 of all 4 to my cart from
https://www.jimellismazdaparts.com/s...category=24722
and it came to $238.23 including the exorbitant sum of $29.95 for shipping.

Edge Autosport appeared at my quick glance to have 3 of these, but I'm not sure they're any cheaper. I'm surprised they don't have a kit of all of them.

The reason most of the discussion surrounds the injector-to-head seal is it's the one that makes you lose pwar. If the stuff sealing it to the rail goes, gas leaks out and the car goes up in flames, then they're no longer worried about power OR injector seals.

[darkmx-6]

Precisionline Fuel Injectors

Sold me a kit for much cheaper than the dealer when I got my injectors cleaned.

While they are out I would suggest having them serviced, you won't regret it. I didn't put enough lube on o-rings and accidentally cut them when putting the fuel rail on. Ended up using my stock o-rings with his cut washers because the stock cut washers fell apart.

Just give them a light coating of engine oil like you would do for an oil filter.

[sharksinspace]

You have the seal itself, the oring, and a few grommets. when i did CS seals in March, the cheapest place i found to buy the orings and grommets was tascaparts.com. they're damn pricey no matter who you get them from.

[GroceryGtr]

toyota seals are not a shortcut, they work just fine. Keep in mind they were designed for a diesel engine, so I can assure you pressures aren't the issue. 90% its the install/prep that causes the failure. The mating block surface needs to be in good condition, if you had to pry the old ones out of the block you'll need to smooth the surface first. CSs are a little more forgiving with damaged mating surfaces due to the increased surface area of the design. So look in the holes and if the surfaces towards the bottom and at the flat base are in good shape toyotas are fine, if there are tool marks and/or scrapes from removing the stuck ones then you'd be better served with the CSs if you arent confident you can smooth them back out. I run toyotas in my built engine and am perfectly happy as are many others. Either way you need to make sure you clean those suckers out squeaky clean at a minimum. Corrosion, dirt, etc will all prevent a good tight seal.

On the seals you have the bottom one(toyota seal) that seals the injector to the block. Then you have a combo of 3 on the top of the injector that goes in the rail. Total of 4 pieces.
The order is(top to bottom):
1. a thin white plastic membrane/washer
2. a blue oring
3. a split hard plastic washer/spacer(black)
4. Actual injector seal - Toyota or CS replacement

You need the split washer and the oring, the plastic membrane only serves to prevent the blue oring from getting stuck in the fuel rail. If I can find my spare set I'll try to snap a pic of reference.

As others have pointed out its probably a good idea to send them out for cleaning/balancing while the engine is apart. The precision guy out of Canada does a good job for a good price and as long as you ask ahead of time will replace the upper blue orings as well for another ~$5. You can also buy the oring kit from him for pretty cheap. Hopefully you have the black split spacers as those are a huge pita to find/replace.

[sharksinspace]

Originally Posted by GroceryGtr On the seals you have the bottom one(toyota seal) that seals the injector to the block. Then you have a combo of 3 on the top of the injector that goes in the rail. Total of 4 pieces. The order is(top to bottom): 1. a thin white plastic membrane/washer 2. a blue oring 3. a split hard plastic washer/spacer(black) 4. Actual injector seal - Toyota or CS replacement.

Five pieces, diagram below.

Grommet
Oring
Grommet
Grommet
Seal

None of the pieces are hard to find, they're just expensive when you're redoing the entire set on all four injectors. Also not a bad idea to replace the oring and grommets where the fuel hardline plugs into the rail, as long as you're already in that far.

[GroceryGtr]

Good catch, I completely forgot thats 2 pieces under the oring. Found a really good pick below showing everything, saves me from having to dig out mine tonight.