CM2250, fuel leak mystery, please help!!

[JMBT]

Ok guys, so I just pulled all my injectors and fuel supply tubes to replace my valve guide seals! I put everything back together and road tested, and the truck ran perfect, better then I ever remember, even when it was new!! I attribute this to super cleaning all the injector tips of the accumulated carbon. I did 3 leak tests and all only lost 220-300 psi in 60sec.
Ok so I took a load from KY to CA. Truck ran great the whole way and had no fuel leaks. However, when I was fueling up last night in Barstow, I noticed there was a puddle of Fuel sitting under the 5th injector supply tube where it goes into the head. I mean a lot of fuel! I cleaned it up and drove another couple hundred miles to my customer. When I got there the same Fuel puddle! The truck is still running superbly and I have done 14 leakdown tests since the job, with the same results. Even a cylinder cutout running on only cylinder 5, and it runs great.
My questions: if there is that much fuel leaking why wouldn’t it show itself on the leakdown or cutout tests??
Also why wouldn’t the truck stumble when running or have crappy performance??

I removed the fuel supply line and injector tube in the Lowe’s parking lot today and everything looks great. I cleaned everything re lubed the o ring and put everything back together at the proper torque specs. Still leaks....performance is still great... and leakdown still 200-300. I am at a los
I have ordered a new fuel connector, retainer, o ring, and supply tube and they will be in Monday morning but I still have no reason why it is leaking??? Any help or ideas will be appreciated. Thanks

[snailexpress]

(01-26-2018 )JMBT Wrote:  Ok guys, so I just pulled all my injectors and fuel supply tubes to replace my valve guide seals! I put everything back together and road tested, and the truck ran perfect, better then I ever remember, even when it was new!! I attribute this to super cleaning all the injector tips of the accumulated carbon. I did 3 leak tests and all only lost 220-300 psi in 60sec.
Ok so I took a load from KY to CA. Truck ran great the whole way and had no fuel leaks. However, when I was fueling up last night in Barstow, I noticed there was a puddle of Fuel sitting under the 5th injector supply tube where it goes into the head. I mean a lot of fuel! I cleaned it up and drove another couple hundred miles to my customer. When I got there the same Fuel puddle! The truck is still running superbly and I have done 14 leakdown tests since the job, with the same results. Even a cylinder cutout running on only cylinder 5, and it runs great.
My questions: if there is that much fuel leaking why wouldn’t it show itself on the leakdown or cutout tests??
Also why wouldn’t the truck stumble when running or have crappy performance??

I removed the fuel supply line and injector tube in the Lowe’s parking lot today and everything looks great. I cleaned everything re lubed the o ring and put everything back together at the proper torque specs. Still leaks....performance is still great... and leakdown still 200-300. I am at a los
I have ordered a new fuel connector, retainer, o ring, and supply tube and they will be in Monday morning but I still have no reason why it is leaking??? Any help or ideas will be appreciated. Thanks

Do you have wetness around ECM plugs and top of the starter?

[snailexpress]

Something like this?
http://rawze.com/forums/attachment.php?aid=3145

[JMBT]

Snail: no not yet. I have not let it drip down there. If I didn’t keep wiping it up it would make those areas wet. Why what are you thinking??

[Signature620]

Could be a poor seal between the steel fuel line and the high pressure connector.

[snailexpress]

(01-27-2018 )JMBT Wrote:  Snail: no not yet. I have not let it drip down there. If I didn’t keep wiping it up it would make those areas wet. Why what are you thinking??

You call it right. Mystery.
I have it leaking from time of my post http://rawze.com/forums/showthread.php?tid=2203. Everything was inspected in Jerry shop. Suspected line to 7th injector welded out. Still leaking.
I don't have any job done on fuel system except new pressure relief valve.

[snailexpress]

(01-27-2018 )JMBT Wrote:  Snail: no not yet. I have not let it drip down there. If I didn’t keep wiping it up it would make those areas wet. Why what are you thinking??

Spray it with brake cleaner and take picture where it starts. In my case all fuel connections are dry. Wrapped fuel lines with paper towel it's dry. Still have wet wires.

[JMBT]

Snail: have you checked the ECM cooling plate, behind the ECM? Maybe?

Signature620: I have ordered both those parts even though the old ones looks fine. I will be replacing them Monday. I hope that gets it.

Still can’t figure how it could be leaking there yet performing so well?? Also only losing 200-300 psi on leakdown test??

[jimeneztrans84]

Maybe a small crack somewhere? Keep up posted if new parts fix the leak.