CM2250 Fuel issue

[Jose9640]

Looks like I have a huge leak somewhere just not sure where to start. When doing a fuel injector performance test they all pass. Did I a leak down test and pressure dropped from 29k to about 500 in 20-30 seconds. Truck shakes and stumbles on a cold start up. Clears up after about 15 seconds and runs just fine after that. Once truck warms up it runs great and no smoke. Where should I start? Injectors?

[Rawze]

start by following the procedures on quickserv.

* First test the high pressure relief valve.

* After you verify it is not the culprit, (usually it is), then you need to start testing injectors with a pressure tester...
http://rawze.com/forums/showthread.php?t...56#pid2556

Otherwise you will be wasting $1,200+ on each injector you mis-diagnose or replace blindly, and may not even find the issue.

[Jose9640]

(01-03-2020 )Rawze Wrote:  start by following the procedures on quickserv.

* First test the high pressure relief valve.

* After you verify it is not the culprit, (usually it is), then you need to start testing injectors with a pressure tester...
http://rawze.com/forums/showthread.php?t...56#pid2556

Otherwise you will be wasting $1,200+ on each injector you mis-diagnose or replace blindly, and may not even find the issue.

Just wanna verify I understood the quickserve procedure correctly. To test the high pressure relieve valve I would install the tester at the relief valve, idle truck and build 29kish psi using insite test. Once pressure reaches 29k it should leak more than 10 drops in 60 seconds. Correct? If did this right, looks like my relief valve is bad. Once it reaches 29k it’s still spraying out quite a bit.

[Jose9640]

(01-03-2020 )Rawze Wrote:  start by following the procedures on quickserv.

* First test the high pressure relief valve.

* After you verify it is not the culprit, (usually it is), then you need to start testing injectors with a pressure tester...
http://rawze.com/forums/showthread.php?t...56#pid2556

Otherwise you will be wasting $1,200+ on each injector you mis-diagnose or replace blindly, and may not even find the issue.

Just wanna verify I understood the quickserve procedure correctly. To test the high pressure relieve valve I would install the tester at the relief valve, idle truck and build 29kish psi using insite test. Once pressure reaches 29k it should leak more than 10 drops in 60 seconds. Correct? If did this right, looks like my relief valve is bad. Once it reaches 29k it’s still spraying out quite a bit.

[tree98]

Here's a dumb question..... if diesel fuel ignites at 234 psi, why doesn't an injector pop tester explode while your using it?

[snailexpress]

(01-03-2020 )tree98 Wrote:  Here's a dumb question..... if diesel fuel ignites at 234 psi, why doesn't an injector pop tester explode while your using it?

You misunderstood whole process. Fuel ignites because air suddenly compressed to 234 psi hot enough to ignite atomized fuel.

[tree98]

Well like I said, it's a dumb question.

[Lonestar10]

Anything flammable has an "auto-ignition" temperature diesel is around 540 degrees it will ignite without any flame or spark. So when you create 234psi of air in milliseconds the air increases in temperature rapidly. If you have a pyro before turbo and watch it going down hill with engine brake on no fuel air coming out of cylinders would still be around 6-700 degrees