KA24DE Injector O Ring Problem

[milto0n]

I'm having quite a bit of difficulty with these o rings on my buddies KA.

Abridged version: Keep tearing injector o rings. Possible causes?

More detailed version: It started a couple of weeks back when cylinder 2 (towards the nose of car) wouldn't fire. Pulled each spark plug and each injector cable to verify. Each cylinder was getting spark. The exhaust reeked of gas. Pulled that injector, replaced it with a spare injector and put on brand new o rings. In replacing o rings, we lightly coated it with new oil. Ran fine... for a day after that. For the next week or so, each injector was going bad (at random) so we pulled each injector and replaced with brand new injectors with new o rings of course. Ran fine for another day before the symptoms returned (car running pig rich, skipping random cylinders, tearing o rings) We pulled the fuel fail and replaced the fuel pressure regulator, replaced the o rings this time lubricating them with vaseline and inspecting the inside of the fail (looked fine to me, no barbs or irregularities.) As of now, the car is still doing the same thing, tearing up LOWER o rings and running rich. Just as an added bonus, we've done an oil change as the oil reeked of gas. We have removed the spark plugs in an effort to allow the gas to evaporate seeing is the engine has been flooding. One last piece of info, when installing the injectors, we alternated in screwing it down, half turns at a time and exercised much caution in installing everything as to not tear more o rings.

Help would be greatly appreciated. Please, and thanks.

[compactfean]

Where are you getting your o-rings from? If they aren't fuel o rings, than the fuel will deteriorate an oil o-ring and leak. Other than that, engine oil and twist side to side with slight pressure has got them in no problem for me for years.

[moso]

the plastic that holds the oring in place can become slightly sloped after years of use. try swapping the offending injector out. I had this problem for weeks after rebuilding my motor. in the end i used assembly lube to oil the orings and then pressed them into the rail with my thumb. it was almost too easy.

[milto0n]

Brand new injectors from autozone (with warranty, and I have taken 2 of the back just because) and brand new o rings from the nissan stealership. Could it be anything to do with engine internals? After the rings are swapped, the car runs great again and has lots of power. Then one cylinder will go bad and sure enough, it is the o ring.

[compactfean]

I don't know how any internal part could affect the o-ring. Maybe something wrong with the rail? Like moso said, you should be able to wiggle then left to right, and pop them right in with your thumb and be done with it.

[Rargetni]

im having the same exact f*** problem! excuse my language. its been buggin me for a while as well. My spark plugs were getting fouled due to the lower o rings going out. switched to some other decent injectors and did the same. Bought BRAND new injectors and still manage to f*** up my rings fouling out my new set of plugs again. let me know if you get somewhere, or ill do the same if i do

[milto0n]

I'll let you know brother, I'm going to get to work on it this weekend...

Would switching to top feed injectors help me in any way? I have a set of 270cc top feed injectors and I wouldn't mind buying the rail since the car is going KA-T in the future anyways.

[moso]

yes that would keep you from having to deal with your current fuel rail/injector combo issue. however, you will need more than just the rail. you also going to need a good fuel pressure regulator. the combo will probably run you somewhere in the 150-300 range depending on which manufacturer you buy from. I seriously suggest staying away from cheap knock-off eghay brand fpr's.