Fueling & Injection - New FIC injectors popping out of rail

So I just installed a new set of FIC injectors. I can't get them to stay in the rail. This is the same setup that has been in the car for years minus the injector swap.

The rails are the speed inc rails with the block style mounts (not the cheap brackets) and it's on a stock ls6 manifold. Using the o-rings that FIC supplied after I told them the setup. Nothing complex. The old injectors never had a problem.

When the pump primes and it builds pressure, you can actually see the injectors get pushed down into the manifold and eventually they leak. I thought I just didn't get them seated the first time so I pulled it apart and reseated all the injectors and it held for about 10 miles and then started spewing fuel again.

I've never seen injectors move up or down between the rail/manifold. I'm hesitant to mill the mounts down since it worked fine with the last injectors.

Thoughts?

Mine did that with the SpeedInc (PP) rails. Swapped to FAST rails and it's never happened. I'm really not a fan of those rails. Running FIC 42's.

I've never had a problem with SpeedInc rails (the expensive ones, not the cheapo ones) on many different cars or this one until now so I think new rails will be my last option.

These are the 1000cc injectors built with the bosch ev14. Any chance it could just be a bad or wrong set of o-rings? They seemed tight in the rail when I put them in. I've just never seen a set move up and down under pressure.

I've never had a problem with SpeedInc rails (the expensive ones, not the cheapo ones) on many different cars or this one until now so I think new rails will be my last option.

These are the 1000cc injectors built with the bosch ev14. Any chance it could just be a bad or wrong set of o-rings? They seemed tight in the rail when I put them in. I've just never seen a set move up and down under pressure.

What manifold base are you using? And what color o rings are on the bottom of the injector?

If they're popping out, your rail is too high. The O-ring is to seal the injector, not to hold it in the rail. Adjust your mounts.

So I just installed a new set of FIC injectors. I can't get them to stay in the rail. This is the same setup that has been in the car for years minus the injector swap.

The rails are the speed inc rails with the block style mounts (not the cheap brackets) and it's on a stock ls6 manifold. Using the o-rings that FIC supplied after I told them the setup. Nothing complex. The old injectors never had a problem.

When the pump primes and it builds pressure, you can actually see the injectors get pushed down into the manifold and eventually they leak. I thought I just didn't get them seated the first time so I pulled it apart and reseated all the injectors and it held for about 10 miles and then started spewing fuel again.

I've never seen injectors move up or down between the rail/manifold. I'm hesitant to mill the mounts down since it worked fine with the last injectors.

Thoughts?Better yet call me on my cell, I'm around all night 770842 0882

Thanks, I just left you a voicemail, but thought I'd post here also.

It's a stock ls6 manifold. Green on bottom and blue on top.

If they're popping out, your rail is too high. The O-ring is to seal the injector, not to hold it in the rail. Adjust your mounts.

The only "adjustment" would be to mill the mount. I'd like to know the explanation before I go that route.

Are these injectors shorter than stock and if so, how much?

Just an update to the thread, I talked with FIC. Very helpful. He explained that the ev14 actually extends into the manifold a bit further than stock injectors (or stock variants). That's where I'm getting my gap at the rail and why I didn't experience it with the other injectors.

So, I'm going to measure and mill those block mounts down ~3-5mm it sounds like to fix it. I feel better knowing the reason.