Leaky injector cm2350

[joed2323]

Tried doing the fuel system leak test thru insite and the fuel rail pressure drops on its ass from 29200 clear below 20000 in about 10-30secs easy.

I assumed it was a faulty fuel rail pressure relief valve on the rail, so I swapped it and still drops like a rock.

So, how do I pin point which injector is dumping fuel?

I did the cyl cutout test and that didnt help.

Id rather not take the truck to kw and give them my money, do they sell a kit to isolate the injectors?

The older cm871s are fairly easy to check which injector is bad but this is a cm2350

[Mr Hagg]

I have a old injector pop tester (rawze made article about it here http://rawze.com/forums/showthread.php?t...56#pid2556 ) that I made a line to go to one injector at a time. Then I pump it up to like 4000 psi and the good injectors will hold. However the ones giving problems will bleed off.

After letting truck set say like 10 minutes how much pressure will it have? Normally bad injectors I see will drop to around 300 psi even down to 10 psi... If it stays around 10000 psi then you may have another issue like in the fuel pump it self letting fuel bleed off.

The way we check the pressure relief valve is simple. Take a 7/8 wrench and loosen up the banjo fitting on the end of the fuel rail. About 2 rounds out. Start the engine see if it leaks fuel. If nothing then run rail pressure up. Most of the time about 12k mark it will start to stream.. There should be NOTHING leaking this is only if the rail pressure gets to high that it will work as a safety valve and relief pressure on the rail so that it doesn't damage anything.

[joed2323]

(11-18-2016 )Mr Hagg Wrote:  I have a old injector pop tester that I made a line to go to one injector at a time. Then I pump it up to like 4000 psi and the good injectors will hold. However the ones giving problems will bleed off.

After letting truck set say like 10 minutes how much pressure will it have? Normally bad injectors I see will drop to around 300 psi even down to 10 psi... If it stays around 10000 psi then you may have another issue like in the fuel pump it self letting fuel bleed off.

The way we check the pressure relief valve is simple. Take a 7/8 wrench and loosen up the banjo fitting on the end of the fuel rail. About 2 rounds out. Start the engine see if it leaks fuel. If nothing then run rail pressure up. Most of the time about 12k mark it will start to stream.. There should be NOTHING leaking this is only if the rail pressure gets to high that it will work as a safety valve and relief pressure on the rail so that it doesn't damage anything.

Im wondering if I can some how make my own metal line and fitting like you did and attach it to a pressure guage with a fitting to supply air to? You have any pics of what you made?

Its well below the 10000 mark after 10mins

[Mr Hagg]

Does it go below 2000? You will need a pump to be able to supply atleast 4500 PSI

[Rawze]

(11-18-2016 )joed2323 Wrote:  Im wondering if I can some how make my own metal line and fitting like you did and attach it to a pressure guage with a fitting to supply air to? You have any pics of what you made?

Its well below the 10000 mark after 10mins

Compressed air doesn't do squat unless it is completely toast and hydra-locking your engine with fuel.

You need a hydraulic pump pushing fuel to it at about 4,000 psi, then watching it for bleed-down to find it. Also it is VERY DANGEROUS AND YOU CAN GET SERIOUSLY SERIOUSLY INJURED, MAIMED, OR KILLED working in the high pressure rail yourself. -- Not worth the risk. Take it to Mr. hag and let him find it for you.

29,000+ PSI of fuel pressure is enough to slice your hand, arm, or face open like a knife at even the slightest unseen leak. It is enough pressure to slice a finger off just by waving your hand past it!. Not kidding..

[joed2323]

Yes the fuel rail psi drops fast

From 29080 psi to well under 89 psi in under 5 mins

[Aleeex]

If for some reason it's the pump let me know. I have one kicking around

[joed2323]

If I have one injector leaking this bad, what if I removed all 6 injectors and look into the cyl through the injector hole, wouldnt the injector thats pissing fuel be the cyl with diesel fuel sitting above the piston???

This may not be the correct way to pinpoint which is my faulty injector but I would think this the easiest way without proper troubleshooting tools

[Mr Hagg]

when you pull the injector out there will be return fuel in the head that will flow into the hole....