6.0 injector tool

As a mechanic I’m always having to trouble shoot hot starts on these 6.0’s and I’ve been working on a project to make all of our lives a little easier. I designed this tool to help you

1. Check for leaking injector seals

2. See if you’re having a hot start issues from significantly worn spool valves.

Spool valves are often overlooked in the chase to find a hot start issues. Even finding a way to pressurize it and see where it’s leaking can be difficult since the oil rail covers up the majority of the injector. Many people replace the O rings and oil rail nipples when in fact they actually have bad spool valves or a failing seal on top of the injector.

Top seal: Some may not know that the top seal of Heui injectors is in face servicable. I recommend servicing all the injector seals any time the injectors are over looked. Alliant Power and Mahle make seal kits that include the top seal.

Mahle part number: GS33711

Alliant Power: AP0002

Spool valves: The spool valve is a part often over looked and hard to diagnose. the spool valves are made with enough clearance to freely float in oil so it can move freely side to side within the injector body. More often than not the spool valve can leak while hooked up to shop air out of the exhaust ports (two holes on top of the injector). This is where a judgement call has to be made. The air leaking out should not be more than a low volume flow that you should be able to cover up the exhaust port and stop the flow. What I look for while testing injectors is for all the injectors to be close to the same flow if any across the board. when you have a bad spool valve you should have a pretty significant about of flow coming from the spool valve exhaust.

Spool valve leakage. In the picture to the left there is a HEUI injector tool connected to a OTC leak down tester. I've used this to gauge what percentage of blow buy I should be getting from a good injector. What I've found is new injectors are going to pass through very little. at a 100PSi you're looking less than 1% of drop compared to a 20-40% of drop on a failing injector.