Injector o-rings are not included in Toyota's valve grind gasket sets (must be purchased separately). If the injectors are not leaking and the vehicle ran good before the head gasket failure, then you have the option of leaving the fuel rail, injectors, and lower manifold together as an assembly (no requirement to disassemble these parts while doing a head gasket).

If however you suspect an injector problem or simply want to be thorough then you may want to disassemble and check things out. Recently I purchased the GB #8-024A injector o-ring kits off of RockAuto.com for $2.08 each (each kit does 1 injector). The kit does not include the big o-ring (Toyota part #90301-23004) that goes between the injector basket & the manifold, but it does have the other 3 parts mentioned.

One curious thing worth mentioning is Toyota's "complete" engine gasket kit (part #04111-73038) does include the big injector basket o-rings, but none of the smaller ones (those can be purchased in the GB kits from RockAuto).

I know in the earlier post I said "avoid removing injectors"........but a little more experience with high mileage vans with ageing injectors has changed my opinion. As of my last job involving injectors I now strongly recommend removing your injectors and having them cleaned/tested by a professional. When it comes to the Portland Oregon area I can't say enough good things about Dr Injector in Gladstone. For $20 each he will clean & test your injectors. He has an amazing collection of specialized equipment specifically for this purpose. The $20 includes initial testing with documented results, cleaning, and retesting. The testing includes spray pattern inspection, flow rates, and internal/external leak tests. When he's done he will install new plastic liners on the tip of the injectors and install new o-rings on them (all included in the $20 fee). You will also get a print-out of your injectors' performance . FYI, if you bring in one of your injector baskets, he'll match up the size and give you the o-rings for those as well .

Sometimes I'm too busy to drive down there so I'll just put the injectors in a box and mail them to him. When he's done he'll give me a call to get my credit card info & he'll ship them back. His name is Wayne and his contact info is: Doctor Injector 610 E 1st St, Gladstone OR 97027. Cell# 503-513-5070 Shop# 503-786-0700. Tell him Tim from Tim's RV sent you!

Here's a flier that gives more info on his service:



Here's a couple other related threads:

https://www.toyotavantech.com/forum/...sure-regulator

https://www.toyotavantech.com/forum/...el-Injector(s)