Are lower O ring failures a common occurrence

[Drake57]

when they are in service for some time, or are most if not all lower O ring problems due to improper or careless installation, or defective/wrong parts?

VH45 fuel rail design seems unique in it's penchant of lower O ring problems leading to hydro lock - apparent undesirable feature of side feed injectors. I've read with interest the hydro lock threads - I'm beginning to dread turning the key.

If a 90-94 Q idles and runs smoothly, is that assurance enough of proper lower O performance? Is a fuel pressure bleed down check appropriate or indicative?

Lastly, are there any simple steps to be sure of proper lower O installation, other than using Infi parts, and being careful? I've seen mention of sending in the fuel rail for rebuild, but does that help insure proper lower O installation?

Thanks, Drake

[maxnix]

I believe the lower O rings are Viton. In any case, using OEM specified O rings usually does not result in a problem.

Removing the fuel rails intact and replacing the O rings in the now separate fuel rail is easier.

Deatschwerks is a good option, reassures the owner of the flow rate (extra data for NICO club members at the base rate), and no known O ring failures.
Modified by maxnix at 3:38 PM 4/11/2008

[AZhitman]

The o-rings don't necessarily "fail". They ARE, however, easy to nick / damage on installation, even with a liberal application of petroleum jelly.

I've had a ton of practice on them and STILL seem to get it wrong on occasion.

Necessitates a replacement o-ring in all instances.

[Q45denver]

Best way is to pressure check fuel rail prior to bolting onto manifold.

[elwesso]

more often than not we see them with improper installation. However we have seen some failures, more commonly in places with crappy gas (AZ and CA)