Injectors are prone to go bad after 5, 10, 15 years in use, depending on the injectors. This bad can be a bad injector that is malfunctioning or an injector with bad performance due to wear and tear over time.
While most of us cannot fix a faulty injector simply because it needs more than injector assembly and disassembly. An injector with bad performance can be fixed and serviced by using a service kit. And here is a quick guide on How to Install an Injector Rebuild Service Kit.
Injector Service Kit
An injector service kit is a widely available package of items that need to be replaced on an injector over time. This includes O-ring, pintle caps, upper rail spacer, micro-filter, plastic caps, grommet seal, etc. All of which can vary depending on the type of injector you have.
You can buy an injector kit at a local hardware store or buy it online. A typical injector kit can cost you anywhere between $10-$100 depending on the quantity.
For our guide, we are servicing injectors of a 1987 Toyota MR2 AGE 16V Gas engine. It consists of 4-injectors that we will be replacing today.
Installing Injector Rebuild Service Kit:
Step 1: We start by the top doing the easy part and replacing the oil ring and upper rail spacer. Start by pinching the oil ring on the side and you can push the other side out. Since it’s rubber, it is easy to remove.
The rail spacer on the other hand is even easier which just slides right out.
Step 2: Once both the oil ring and spacer are removed. Start by placing the new upper rail spacer. Just slide it in, and it should be at its place. Then put the new oil ring, you might have to stretch on one side to fit the other. But again it’s rubber so it should be easy.
Step 3: Now we move on to remove the pintle cap. The pintle cap works as a protector to protect the fragile pintle end of the fuel injector. Older pintle caps are easier to remove and can be done by pulling them out.
With simple raw strength, you can pull the pintle cap out while rotating it sidewards. That way it should be easy. Again be mindful of the pintle tip as it is fragile.
Step 4: Unlike the old pintle cap, the new pintle cap would not go all the way in. As it is rigid. So you first start by installing the new pintle cap. Just slide it in from the top while gently pushing it downwards.
Once it is all the way in, now we will need to heat the pintle cap, so we can lose it and stretch it out to reach the bottom and properly fit. Using a hot air blow gun, we heat the cap and pull it downwards. Then again heat it and pull it downwards.
The process is repeated until it reaches the bottom. Be mindful of the heat as it might get too hot and melt.
When you are done with it, the pintle tip should be out of the cap and visible.
Step 5: After the pintle cap, we install the lower grommet (insulator or dampers). The grommet has a particular way to install, The side with the lower end goes towards the bottom while the wider stays upwards.
Similar to all other parts, you push the grommet unless it slides in its place.
Step 6: With the lower grommet installed we are only left with the micro-filter, which is located inside the injector. So we need to get handy with its removal.
Note: The micro-filter has harmful contaminants in it so be sure to use gloves for protection.
You first start by finding a screw that fits inside the micro-filter and securing it into a vise as in the image. Then go ahead and screw the injector/filter into the screw. Enough so that the screw holds the injector firmly. Then all you need is a simple pull.
That should be enough to pull out the injector micro-filter.
Step 7: Finally we go ahead and install the new micro-filter. A simple push should do the job. In the end, using a hammer, gently tap on the filter to secure it inside the injector.
And there you have it. Your old injector is now serviced and ready to perform as new. Repeat the same with other injectors and you would be good to go.