First autococker build with velocity issues

[Bigstorm87]

So I've got a cocker build that I'm having issues with as the title says. It's my first, so go easy on me. What I have on her now:
Inception bolt and pin
All Shocktech lower tube kit
Gen 2 CP HPR
Inception ram
Bomb 2 three way
Shocktech LPR
Inception RIP frame
Three way is done according to Inception specs

So starting out, I have the HPR zeroed, and the IVG backed out to flush. Slowly I add pressure to the HPR until the gun cycles fully. Then I start screwing in the IVG, firing a few blanks, and then chrono. I cannot get the fps over 120-130. If I continue to turn up the HPR, the gun will fire, but the block locks to the rear. Pushing the timing rod forward lets the block come back forward. My thought is that the LPR is over pressured, and/or there is an issue with the timing rod or trigger frame not letting the 3 way finish the cycle. I'm stumped guys. Pleeeease help my out 😮💨😮💨

[Sottyman]

Can you isolate this for us? Turn the LPR ALLLLL the way down to zero (essentially turning it off). Will the gun get up to velocity (280-300 fps) with increased HPR pressure, but you'll have to manually cycle the gun?

I'm thinking you're right, there's something LPR/3 way related, but just asking for starters!

[Trbo323]

You definitely have 2 separate issues

1) velocity
2) 3 way/LPR

Get it shooting and cycling again, then at rest (with the block/bolt forward) pull the back block back by hand. It should be difficult but not impossible to pull back.

If you get your LPR set there. Then try to get the velocity up, if the back block goes back after increasing the HPR then you likely have a LPR issue as it should hold the same pressure you had it set to.

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[defiantguy99]

Ivg two turns in from flush is a good starting point. Turning off your pneus is also good advice, just need to manually pull back the block to recock and reload paint. You should be able to set your HPR without pressure tester if you have access to chrono, sounds like you do. Turn pressure up till your fps starts to drop then back it off till you are at max fps again. Other than that make sure you have good paint to bore match, and might need stiffer hammer spring and or lighter valve spring.

[superman]

IVG 2 turns in, reg set to 300 psi and you should be shooting 300fpsish.

[Buff_phroggie]

I had a gx5 doing something simmilar a few months back. I just kept playing with timing until i learned what it liked. I think it had something to do with the hammer lug, i noticed it was also exceptionally humid when it happened

[Bigstorm87]

I tried everything y'all. I have a gauge and it cycles at a measley 80psi. After that the block locks back when fired. Turning off the lpr and slowly increasing the pressure did nothing. It's a brand new shocktech! I can't imagine it being faulty or anything. Any more ideas to try?

[superman]

missed the locking to the rear part. is your lpr over pressurizing? If you air it up and let it sit does it blow a hose?

[Bigstorm87]

So the sequence is this: gun fires, cocks back, and stays there. At 80psi in the hpr, it cycles, any higher, it locks. If I zero the lpr and increase slowly at 80 psi in the hpr, the pneus pressurize like normal. From there I try to increase the output of the hrp and fire, bolt locks back. Forced to manually push the timing rod back manually to finish the cycle. It's as if the air bypasses the lpr altogether.

[superman]

Which would make since if your lpr is over pressurizing.
your hpr should be in the 240-300 psi range. The lpr should be in the 60-100psi range. If the lpr only receives 80 psi from the hpr it will appear to function normally.

[Bigstorm87]

Do you suppose the reg was bad from the beginning? Like does that happen?

[superman]

I would say it does not happen regularly, even further to say rarely.

[Trbo323]

So the 3 way is not resetting on its own? If that's the case the o rings are likely dead, have too much friction or there's just not enough lube in the 3 way

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[Bigstorm87]

Might I add that trying to turn the knob on the lpr is very, very difficult. Like it's under a lot of pressure. And the 3 way is brand new as well. Lubed with a light coating of dow 33

[CatFarmers]

I was working with a similar issue using a Bomb 2...turned out my stroke was too short not allowing air to vent fully. A quick adjust to timing fixed it right up.

[Magmoormaster]

So just to clarify, if you turn the LPR off (turn the knob counterclockwise to decrease pressure), and you then increase the HPR, the pneumatics still get pressure?

Also yes it is supposed to be pretty hard to turn the knob when pressurized. You don't want your settings to change if you bump it.

[Bigstorm87]

Alright so I tested my theory that it's the lpr. I took off my brand new shocktech reg and put on an old ANS jackhammer reg. Set the hpr to 300. A little tuning and it started cycling. First shot was 273 on the chrono!

[superman]

The shocktech lpr needs a new shrader valve. The ones Shocktech uses are apparently a bit higher end than a standard car tire valve.

[Bigstorm87]

Thank you. I'll see if I get get one ordered.