Steyr LP10E Misfire while cocking? Conundrum... RESOLVED!!!

[Chris__Colorado]

I've had this Steyr for several years with no issues.
Recently, when cocking the pistol, the electronic trigger fires.
No air is discharged.
It can take several tries to cock.
This is an intermittent problem...but is happening now at all live fire shooting sessons (2-3 times a week). It only started about a month ago.
Tried 2 different sets of fresh batteries, and checked the connection between the electronics in the grip and gun and the connector looks fine (no electrical/continuity testing done).
Annually, I'd say about 6500 pellets are fired along with 12-15000 dry fires (about 100-150 live fire a week, with double the number of dry fires weekly)
The gun has not been serviced in 3+ years.
I understand it is probably due--but I don't see how worn out seals could cause this type of problem. No airleaks of any kind.
However, I can't see how cocking would cause the trigger to "click" / fire.
No adjustments (trigger/grip/etc.) have been done to the gun other than the occasional click or 3 on the sights.
The gun works fine once it stays cocked--and by cocked, I mean the electronic trigger hasn't fired/clicked.

Anyone have any ideas?

Thanks
Chris

************CONUNDRUM RESOLVED! THANK YOU ALL!*********

A special THANK YOU to "therider" and "argus"
Your insight was right on target.
I ordered the parts in question from our forum host, Pilkguns, along with a "service kit" of parts.
***See attached image of parts lists ***
The red/pink are the repair parts. They were the culprit as near as I can tell--probably just worn out. All parts I reference are according to the parts Figure # in the mechanical drawings.

I'm glad I got screw #78, as the original got chewed up when I removed it. Figure parts #78 (screw) and #81 (spring) aren't really necessary, but since I was doing going to do a full service, I'm glad I got them replaced.

The green parts are what arrived as part of the "service kit" I asked for. Jennifer at Pilkguns was great to work with. It made the order really easy. When the parts arrived (each in their own plastic bag), I wrote down the mechanical drawing Figure # on each bag. This made it much easier to identify which parts go where. As a result, part 29.8 confused me a bit, as it isn't shown in the LP10E mechanical drawings, but IS shown in the LP10 drawings. It is inside the pressure regulator. I'm glad I had both sets of mechanical drawings from the Steyr website. Be very careful disassembling the pressure regulator as it is full of belleville spring washers--I used Figure #27(Grip Bar 40080200010) and slipped it into the bellville spring washer stack to keep the orientation and stacking order intact for later assembly. If you mess these up, just pack them up and send it all to PILKGUNS as regulators require special equipment to set up. I was especially extra careful to keep everything oriented the same way and in the same order.

Note the parts in the Yellow EXTRA section (my second parts order to our host-PILKGUNS). Despite my precautions, one of the Figure #68 springs disappeared when I took apart the recoil absorber. Neither I nor my eagle-eyed assistant saw this magic occur. So, I ordered 4 to replace all of those springs. Figure 29.11 and 30 are extra screws for the pressure regulator, as one of mine was buggered up from some previous work (of unknown origin-I bought the gone used), so I got a replacement and a spare. The other yellow parts are just some spare O-rings; the ones most exposed and likely to fail, but easily replaced.

Overall, the entire process took about 5 hours because I went very deliberately, and include the time reassembling the gun with the missing Figure #68 spring. I figure someone practiced could do it in under two hours (especially if they have parts on hand and aren't afraid to loose some). When I did install the Figure #68 springs (just remove rear sight and grip), I learned that you must install the rear sight screw back into the frame to reset the recoil absorber so you can properly adjust the recoil absorber spring per the video instructions.

Bottom line: Everything works great now! I appreciate all the Steyr companies drawings and videos, and most importantly, the help from the this forum. My son is very happy to have his gun back.

I think that sending the gun to PILKGUNS is probably best, and probably much quicker too, but I had fun doing this with my son - who was the official videographer, photographer, and eagle-eyed consultant during our initial disassembly-assembly. It was a great way to spend a Sunday afternoon.

THANK YOU!
Chris
PS I also ordered some tools via Amazon to support this project!
1. Rennsteig Parallel Pin Punches with Sleeve (Pin Remover Tools) - 8 Piece Set
2. Mayhew Pro 25015 2mm Pilot Punch
3. Fixxxer Hollow End Stainless Steel Starter Punch Set by Fixxxer LLC
4. Bondhus 20899 Balldriver GoldGuard Finish L-Wrench Double Pack, 38099 (1.5-10mm) and 37937 (.050-3/8-Inch) (all I used were all the keys between 1mm and 3mm)

[argus]

Certainly a strange problem I've not seen before.
Steyr have some very good service videos http://www.steyr-sport.com/index.php/en ... ice-movies

Have you tried just removing and reseating the trigger assembly to ensure it is located correctly and giving everything a good clean.https://www.youtube.com/watch?v=jvIa2bea0iQ#t=11

While you have the trigger assembly out check that the screw that holds the little pcb with the microswitch attached is tight and the microswitch itself is not coming away from the board.
https://picasaweb.google.com/1100585107 ... 6056758322
https://picasaweb.google.com/1100585107 ... 3744632290

Are you sure it is the electronic trigger firing or could it be a mechanical issue of the catch detent (80) not reliably engaging and locking the striker (19) in the cocked position. While the trigger assembly is out and with the air cylinder removed can you reliably cock the pistol and simulate firing it by pressing on the catch detent (80) with the tip of a pen (in the photo you can see where the shaft of the solenoid hits the catch detent to fire the pistol)
https://picasaweb.google.com/1100585107 ... 2884119986

[Chris__Colorado]

Argus,

Thanks for giving me some things to start looking at.
I've watched the videos and looked at your pictures.
I'll be buying the appropriate tools (punches) before I start anything and will let you know what I find.
Thanks again.
Chris

[argus]

My pleasure Chris,
Photos are from another members excellent blog so all credit to Igor http://toz35.blogspot.com.au.
I'm not suggesting any major removal of pins or springs at this stage, all you should need is some metric Allen keys and small flat blade screwdrivers to isolate the problem to either the electronic trigger or the catch detent/striker asssembly. Obviously any doubts or if you are not comfortable pulling things apart our host is the go to guy to get your pistol working again. Make sure air cylinder is off and no pressure in the system before you start.

[therider]

Check this old post of mine. I had similar problems....needs to be repaired .
http://www.targettalk.org/viewtopic.php ... e+problems

[argus]

Finally I got it back!
they have changed the "Schlagstückes" (hitting parts) and the "Fangrast" (part n.80)
Also they have reset the trigger and the VO (which i guess is the velocity).
But, very annoyingly, they have scratched both my compressed air bottles! One of them very severely!

The catch detent "Fangrast" (80) and striker "Schlagstückes" (19) are the parts I suspected may be involved from Chris' description.
Could be wear or damage so these parts are no longer engaging and would require replacement.
Also worth checking spring (81) which applies pressure to the catch detent, is in place and screw (78) which loads the spring has not loosened .

[argus]

Well done Chris, glad to hear you have your son's LP10E up and running again!!
I think the only thing I'd do differently is not disassemble the regulator because as you say, it can require special tools / adjustments etc. I thought removing the four #30 screws allows the regulator to be removed as an assembly. Perhaps replacing the #29.1 screws (usually they are marked with red locative) one at a time would avoid disassembling the regulator and the possibility of causing issues if they were the damaged screws you wanted to replace. Also not sure of the what the impact of under or over torquing these two screws may be.
May be worth considering a check of pellet velocity if you have a chronograph after disassembling the the regulator and tweaking it back to Steyr recommendations if it has drifted (Steyr service videos are your friend).

[Chris__Colorado]

Well done Chris, glad to hear you have your son's LP10E up and running again!!
I think the only thing I'd do differently is not disassemble the regulator because as you say, it can require special tools / adjustments etc. I thought removing the four #30 screws allows the regulator to be removed as an assembly. Perhaps replacing the #29.1 screws (usually they are marked with red locative) one at a time would avoid disassembling the regulator and the possibility of causing issues if they were the damaged screws you wanted to replace. Also not sure of the what the impact of under or over torquing these two screws may be.
May be worth considering a check of pellet velocity if you have a chronograph after disassembling the the regulator and tweaking it back to Steyr recommendations if it has drifted (Steyr service videos are your friend).

:-)
Argus, you are right on!
I would definitely preferred not to mess with the regulator, but, the service kit included a single o-ring that I could only find inside the regulator--and not being one to shy away from a challenge...I went for it--very,very deliberately. It wasn't too bad as I knew what to expect and took it apart very slowly to keep all the pieces intact, in sequence, and in the proper orientation (maintaining my own (and no one else's) scuba equipment 30+ years gave me a little bit of regulator background).
As for checking the velocity--we knew the Steyr LP10E felt and sounded hot....but 590+ feet per second (180+ meters per second) was a big surprise! 3 shots to confirm it was real and then back to work. It's back down to a much more appropriate 520 fps +/- 6 fps (10 shot string) now. I'm sure someone, somewhere has done to math to correlate velocity variation with potential point variation---but I'm happy with that result (given the statistically small sample to determine the observed velocity range).

I guess I should point out that what I thought was the trigger firing in the original post was really the striker being released after being cocked. Those parts must have been worn out enough not to allow them to work.

All in all, a great experience. You can really see and appreciate the the Steyr design and how it works when you do your own service--a true engineering marvel.

Now, I just need to post my experience with my daughter's gun (FWB Model 2) that also decided to fail within a week of the Stery and how I repaired that pistol. March was not a good month for our airgun pistols--but now, all are up and running. I still get a kick out of the fact that my daughter shoots a pistol from 1983 with a "current" and "legal ISSF" cylinder that only a few years younger (1985) than the gun-but is pressure tested marked 2012 by FWB. FWB support for legacy products is amazing!

VR,
Chris__Colorado