So i was looking into getting new injectors to help with gas mileage on my 99 XJ 4.0 (204,000m), so i went out and looked at my injectors. My injectors seem a little too "clean" to be the original set. And all the injectors i seen in the JY usually have a gray tip. But the injectors installed on my rig have a blue tip. I know a lot of people here have swapped injectors, so i was wondering if the blue tipped injectors are anything special? If not, whats my best option for an injector upgrade for the 99's. NON-coil pack. I still have the distributor setup.

Thanks guys!

 

What is the last three digits of the injectors?

 

Do i have to remove them to see the numbers?

 

No you can rotate them. Are they fat bodies or thin?

 

Take a picture of em. Oh and upgrading your injectors is not going to help with your mileage I hate to break it to you. They wont really make a difference at all. You'll even lose gas mileage for the first few tanks of gas as your computer "re-learns" after the swap.

People who report seeing gains in mileage after an injector swap more than likely just had dirty old injectors. So my advice would be if the only reason you want to swap injectors is for a gain in mileage, then just run some Seafoam or Lucas fuel treatment and that's the best it'll get.

But to answer your question, injectors that came from the factory are black/grey so if you see blue on em, they're more than likely aftermarket.

 

x2. Or they were aftermarket replacemnts for stock.

 

They are thin bodied with blue tips going into the head.. The PO replaced the head and all the associated seals. Im thinking he probably replaced the injectors too. I know replacing them wouldn't improve my mileage unless there is funk in the current injectors. And if they were original im sure they would be pretty gummed up. I'm curious at this point what kind of spray pattern they have if they've been replaced...