fuel pressure issues

[RogerH]

I have a 06 ms6. I'm running autotech internals. I'm also running a 5 gallon mix of e85. My prv went bad last week and I was getting huge drops in pressure under boost. I replaced the prv and the problem went away. Last night under full throttle in 3rd gear I noticed fuel pressure was dipping into the 1300psi range then going back up to 1650+ psi. The dips are happening in the 3-4k rpm range. Is it possible my internals coukd be bad? They have about 20k miles. Also could it be the spill valve? I thought when the spill valve failed you just got in tank pump pressure around 60psi. What about the x ring in the pump? Has anyone had it fail? I've done some searching and I can't figure it out. I'll post a log this evening. Thanks for the help.

Fwiw I checked the new prv and it holds pressure when the car is off. So I'm sure the new prv is good.

[Etipp98]

Take the pump apart, clean the spill valve, clean/relube the internals and change out the x-ring. McMaster-Carr

[RogerH]

Ok I'll do that. Any idea on fuel filter life on our cars?

[06Speed6]

Fuel filter is a part of the in tank fuel pump assembly and is designed to last the life of the car.

[Sid3wayS]

Originally Posted by Etipp98 Take the pump apart, clean the spill valve, clean/relube the internals and change out the x-ring. McMaster-Carr

Is that the outside o ring?

[Etipp98]

Originally Posted by Sid3wayS Is that the outside o ring?

Internal one that the piston slides on.

[Tokay444]

if someone in the states could get me a pack of those orings, i'd greatly appreciate it and pay for shipping.

[Etipp98]

Originally Posted by Tokay444 if someone in the states could get me a pack of those orings, i'd greatly appreciate it and pay for shipping.

I bought a pack of 100 how many you want?

[Tokay444]

i would have taken the whole hundred as well at that price, but i'm sure 5 or 6 would suffice.

[shnouz]

Originally Posted by RogerH I have a 06 ms6. I'm running autotech internals. I'm also running a 5 gallon mix of e85. My prv went bad last week and I was getting huge drops in pressure under boost. I replaced the prv and the problem went away. Last night under full throttle in 3rd gear I noticed fuel pressure was dipping into the 1300psi range then going back up to 1650+ psi. The dips are happening in the 3-4k rpm range. Is it possible my internals coukd be bad? They have about 20k miles. Also could it be the spill valve? I thought when the spill valve failed you just got in tank pump pressure around 60psi. What about the x ring in the pump? Has anyone had it fail? I've done some searching and I can't figure it out. I'll post a log this evening. Thanks for the help. Fwiw I checked the new prv and it holds pressure when the car is off. So I'm sure the new prv is good.

My 6 was doing this exact thing a few days after installing my KMD internals. Turns out the guy who did the install for me didn't use a torque wrench and over tightened the top cap. The piston would eventually smack the top of the pump causing pressure to drop to around 1200psi. Try a re install w a torque wrench and definitely clean the spill valve.

[RogerH]

The cam lobe wore a groove in it where the autotech internals were riding and the keepers fell out and tore the lobe up. Shit happens. This weekend I'm replacing the intake cam and installing a cpe pump. Autotech was awesime. They replaced the internals for me. The above is just a guess. I don't know how it happened, I just pulled the pump and the spring was loose, and the keepers were gone and the cam had a groove worn down the center. A deep groove. I seem to be the only one to have this issue as far as I can tell. Maybe my stock cam was defective. My car has 140k miles, and my internals had about 25k miles on them.

[hnda etr]

Originally Posted by RogerH The cam lobe wore a groove in it where the autotech internals were riding and the keepers fell out and tore the lobe up. Shit happens. This weekend I'm replacing the intake cam and installing a cpe pump. Autotech was awesime. They replaced the internals for me. The above is just a guess. I don't know how it happened, I just pulled the pump and the spring was loose, and the keepers were gone and the cam had a groove worn down the center. A deep groove. I seem to be the only one to have this issue as far as I can tell. Maybe my stock cam was defective. My car has 140k miles, and my internals had about 25k miles on them.

Ummm.. where is the cam follower bucket?

[RogerH]

It came loose some how and got torn up inside the housing. I found it in pieces.