If you remove your fuel injectors, you MUST replace the o-rings

[PhoenixGTS]

For archival purposes, I have had my injectors out twice now to paint my intake manifold (first color was just not right) and both times, virtually every o-ring on the injectors failed when I tried to re-use them (I tried the second time since the rings where only a few months old and I thought I installed them improperly the first time). A whole new set is about $50 so don't scrimp. In a pinch, Autozone has a miscellaneous package of fuel o-rings which includes the two sizes you would need for one injector if you only have to take one out for diagnostic purposes or similar.

oring o ring

 

[acrdakota]

*** are you using any type of non-petroleum based lube on them when installing the injectors? I have done many many intake manifold swaps on various vehicles and have never had to replace all the O-rings. On occasion one will be torn and have to be replaced but it's not a common occurance.

 

[SNKEBIT]

*** are you using any type of non-petroleum based lube on them when installing the injectors? I have done many many intake manifold swaps on various vehicles and have never had to replace all the O-rings. On occasion one will be torn and have to be replaced but it's not a common occurance.

what he said. I do injector swaps all the time and never have a problem. Use some lube, and they slip right in.....

 

[PhoenixGTS]

*** are you using any type of non-petroleum based lube on them when installing the injectors? I have done many many intake manifold swaps on various vehicles and have never had to replace all the O-rings. On occasion one will be torn and have to be replaced but it's not a common occurance.

Just a bit of engine oil as directed by the service manual (which says replace them every time). Apparently what happens is once in service, then removed, they swell. My theory is the larger size causes them trouble on reinstall (the brand new ones feel very different on install and go in much more easily). On this last go around all 20 o-rings were damaged when I took them back out to repair a leaky injector (leaked enough fuel out to fill a couple of the galleys created by the webbing on the top of the block).

You guys are swapping injectors on Vipers? Or on other vehicles?

 

[RobHook]

Engine oil? It's very odd that the manual would recommend that as it's usually a no-no to use any type of oil on a seal that may be (even partially) natural rubber. I imagine these o-rings may be a special compound but I'd still use silicone. I've removed mine a couple times (not all of them) and have never had a problem. This is using Gunk (or Mercedes-Benz) Silicone Spray as a lubricant.