I know it has been said on here before that even stock cars have boost leaks. I didn't think much of it until I picked up the parts to build my own boost leak tester and applied less than 10 psi.

Low and behold 3 out of 4 injector insulators were pi$$ing air. Cylinder 2 was the worst offender.

It was a weekend after 1pm when I tested and Mitsu was closed and I couldn't wait to get my daily driver fixed.

I took my injector insulators to NAPA. After searching in 4 different books they couldn't find a listing for any mitsubishi but then they went the extra mile and broke out the calipers to take comparison measurements. Since his books didn't list the measurements the counter guy went box by box until he found a match. He didn't have just the insulators in stock but he did have the entire injector seal kit with o-ring and insulator.

For those that have not done a boost leak test you need to. My mileage has increased, car runs smoother, and power is quite improved all from fixing these factory delivered leaks.

See attached pictures of leaking insulator, boost leak tester, and NAPA box with part number that fits our cars. I picked up the 2 inch x 1/2 inch PVC and brass reduction fitting from Lowes. I finished making the boost leak tester with a 2" to 3" Spectre silcone connector from Autozone. This one worked world better than the Fernco ghetto rubber boost leak tester I previously used on my old '95 GS-T. Some of you are likely saying, "the inlet on our turbos are 2.5 inch so how did a 2" to 3" adapter fit?" I took a chance and as you can see in the photo attached that a standard worm drive hose clamp reshaped it down to 2.5" without any problem. I tested it to 35 PSI after replacing the inslators and it held without any leaks. Hopefully this helps someone else. Couldn't figure out how to imbed the images so attachments will have to suffice for now. Enjoy and boost leak test your EVO if you have not yet!

Rich

 

how many miles does the car have??

 

Car had been acting this way for some time but I tested it at 10K.

 

sounds like good advice. Might have to use it if I buy an evo before the end of the year

 

I know it has been a while since this thread was last replied to, but...Has anyone else used this NAPA part (NAPA Part #:2-12069)? If so, how long has it lasted?

 

Check the throttle body seals

 

I was also curious about the NAPA Part #:2-12069 reference above. It would be much easier to just grab these then have to order them from STM or somewhere and wait for them to come in a week.

What is the difference between the insulator and the o-ring?

Thanks for the info

-Ethan

 

Nice bit of info! NAPA has a lot of parts that thought was hard to find.

 

I bought 4 of these kits this weekend from NAPA installed them and they worked beautifully! Total came to about $19 for all 4. All I changed was the lower seal. For the first time in 4 years im boost leak FREE!!

anyway theres are a great alternative to the mitsu ones and seem to be of good quality.

-Ethan

 

Back in the DSM days I used to put a spacer washer over the injector head to put more pressure on that seal. That works in a pinch (whe your a poor college student).

Good find on the injector seal.