I had this same issue with number 7 for a while. I finally pulled it to inspect it and found the cushion ring (top square-ish O-ring) was rolled the last time I installed the injector. Replacing all the O-rings on that injector and making sure I didn't roll any this time put an end to that problem.

One other possibility is over-torque on the bolt, and it's now stretched and has too much give. A fresh bolt and making sure of your torque wrench readings may be the call. I recently bought a digital torque adapter [LINK] to be certain I don't over/under torque. With 3 of my 4 torque wrenches, I found this to be very enlightening. I've had other people with their $500 torque wrenches in there - followed shortly by a loose injector. I think starting with a fresh lower bolt, O-rings, an accurate setting on the wrench, and a hot-torque is your best chance for dealing with an impish prairie dog. If that fails, blue Lok-Tite has treated me pretty well - with an occasion miss here or there.

 

tugly thanks for your help. I tried all new bolts & orings washers &cleaning threads & dry hole & light oil on threads different wrenchs. Works on all but one. A fellow above asked about how to fix this. helicoil? Advise and help left. nossliw? gaugepro? Can yall help? Somebody here have the answer? even tugly could benefit. he tries to help everybody.

Reckon if you dont have the problem it ain't one til you do. Im gonna see if another forum has the know how.

 

If you really think the bolt is loosening, you could drill the bolt head for safety wire.

 

thnk you. I know it is loose I can turn it nearly no force. 7 other 1s dont do this. Doin cups in another one all were tight. did injectors in it a year ago. No other things wire i sit

 

anybody else??

 

Not quite sure what you're asking? I would do as Tugly said. I did the same but minus the locktite.

 

In that case, I'd probably go ahead and safety wire it. The torque spec is engineered for the application, and it specifically says to lubricate the threads with engine oil. To use thread locker effectively, all the oil needs to be cleaned from the threads, both the bolt and cylinder head. Unless you were to use an ungodly amount of thread locker, there won't be enough lubrication on the threads to achieve the engineered clamping force, IMO.

 

in my early message I put I had used oil. I do not want to use loctirte unless I have to.

Is a safety wire gonna work if threads are worn?

What does anybody think of helicoil idea?

 

Safety wire is a sure thing. It requires some drilling and thought, though. Make sure you wrap the wire in the correct direction.