LLY: Help me spot this leak

[Robby Avery]

I dont have any of Kennedys tools.....they are kind of pricey. But I do want one.

I dont have a tech 2 but I have an autel maxsys scanner and I have a v2. could i use the V2?

If the scanner you have will allow the actual fpr vs the commanded fpr you can check and see if the graph shows a smooth lines chances are your fpr is ok or as gm says within normal operating specs if you depress the throttle pedal and the graph moves and the actual and commanded are corolated smoothly more than likely you fpr is fine if the graph looks like a sharks mouth shark tooth pattern at idle you more than likely have a faulty fpr and even though the truck runs and drives fine when wot is commanded the rail pressure might not reach peak pressure also you could have a issue with you fpr valve not building pressure or prematurely releasing due to a weak spring no p0093 low rail pressure codes I pressume? No shim kit installed?

 

[cstephens93]

If the scanner you have will allow the actual fpr vs the commanded fpr you can check and see if the graph shows a smooth lines chances are your fpr is ok or as gm says within normal operating specs if you depress the throttle pedal and the graph moves and the actual and commanded are corolated smoothly more than likely you fpr is fine if the graph looks like a sharks mouth shark tooth pattern at idle you more than likely have a faulty fpr and even though the truck runs and drives fine when wot is commanded the rail pressure might not reach peak pressure also you could have a issue with you fpr valve not building pressure or prematurely releasing due to a weak spring no p0093 low rail pressure codes I pressume? No shim kit installed?

Right no fuel related codes thrown ever. And yeah I installed the ppe shim kit a month or so ago when I did my head gaskets and studs

 

[cstephens93]

How many times with low rail pressure does it take for the code to be reported?

 

[DieselBulldog10]

I am having the same issue with my truck. I've rebuilt mine 3 times as well. Interested to hear what a good fix may be other than removing it.

 

[cstephens93]

I am having the same issue with my truck. I've rebuilt mine 3 times as well. Interested to hear what a good fix may be other than removing it.

I'm actually just going to replace my filter head as it seems mine may be cracked since ive rebuilt it before as well. Just one more thing to spend money on.

 

[cstephens93]

If the scanner you have will allow the actual fpr vs the commanded fpr you can check and see if the graph shows a smooth lines chances are your fpr is ok or as gm says within normal operating specs if you depress the throttle pedal and the graph moves and the actual and commanded are corolated smoothly more than likely you fpr is fine if the graph looks like a sharks mouth shark tooth pattern at idle you more than likely have a faulty fpr and even though the truck runs and drives fine when wot is commanded the rail pressure might not reach peak pressure also you could have a issue with you fpr valve not building pressure or prematurely releasing due to a weak spring no p0093 low rail pressure codes I pressume? No shim kit installed?

So i used a scanner today to control fuel rail pressure and the furthest I was able to get it was 160mpa. The scanner wouldnt let me go any higher than this. I'll attach a picture. My truck was able to match the desired rail pressure, obviously the truck sounded like it had almost a lope tune on it haha.

I was on my DSP position 1 tune, which is just a heavy tow. Should I be able to go higher than 23kpsi? Or is that the most that can be commanded.

160mpa is converted to 23206.032 psi

 

[NC-smokinlmm]

Probally a cracked filter head...

 

[cstephens93]

Probally a cracked filter head...

Yeah I have another filter head on the way now

 

[Robby Avery]

So i used a scanner today to control fuel rail pressure and the furthest I was able to get it was 160mpa. The scanner wouldnt let me go any higher than this. I'll attach a picture. My truck was able to match the desired rail pressure, obviously the truck sounded like it had almost a lope tune on it haha.

I was on my DSP position 1 tune, which is just a heavy tow. Should I be able to go higher than 23kpsi? Or is that the most that can be commanded.

160mpa is converted to 23206.032 psi

Looking at your picture I need to see fuel pressure regulator command vs fuel pressure regulator actual in a graph from to determine if the fuel pressure regulator is you limiting factor if I'm not mistaking lly hare still at the peak of 23k rail pressure due to the fact that 26k wasn't seen till LBZ cp3 were introduced were talking stock cp3's not modded ones the housing is usually what cracks think about it the housing is hanging suspended with some of the vibrations of the Diesel engine ending there causing it over time to just crack let us know how it does

 

[cstephens93]

Well I managed to buy a factory filter head from a guy named Doug on the forums. He shipped it from Cali and I received it in Florida about two days later.

I spent like 4 hours replacing it because those darn fuel lines were a pita to get off.

After installing it and a few hard runs and about a week of driving with it, no leaks whatsoever. So it looked like it was my filter head cracked somewhere

 

[c20elephant]

Next time new primer assembly with a filter is about $120.00 through Amazon

Genuine GM 12642624 Fuel Filter

 

[cstephens93]

Next time new primer assembly with a filter is about $120.00 through Amazon

Genuine GM 12642624 Fuel Filter

Yeah the primer assembly is what I meant. My bad.

Replaced the whole thing

 

[295PRO]

In rebuilt my housing bout a hour ago cost me like fourth bucks. Nothing to it.

 

[cstephens93]

In rebuilt my housing bout a hour ago cost me like fourth bucks. Nothing to it.

I ended up replacing my entire filter housing for like 80 bucks. No leaks anymore

 

[Slowmax]

Yeah I figured Im just going to try and rebuild it once again and hope this solves the issue

Just had this happen in that exact location on my truck. Rebuilt the filter housing with Merchant's kit and the fuel leak went away.

 

[cstephens93]

Just had this happen in that exact location on my truck. Rebuilt the filter housing with Merchant's kit and the fuel leak went away.

Yeah, I rebuilt mine once and it didnt stop the leak. So like I said, after being annoying long enough, I made this thread and someone messaged me with a filter assembly for sale, so I bought it and installed it and no leaks anymore