MikeT 88IROC350

Well i just got vent a little about this fuel leak i am trying to fix. Havent really posted much about it....just normal TPI maint stuff. Pulled all the top TPI and fuel rail/injectors. Had a visible leak near #5 inj. Figured it was one of them O-rings in the rail system. No big deal. Figured i would service the injectors while they were out. Sent them to FIC. Maybe had a bad Oring on those as well, (ethanol fuel?) so got them back, and new rail seal kit, and been putting it all back together. Not so fast, made 2 crucial mistakes.
1st, got it MOSTLY all back together, before just trying a pressure check, see if i had any leaks......bad move! all i had left to do was put the MAF and intake duct back on, and it was done! so before i did that, hooked bat back up and hit the key. Only took about 10sec to see the leak again...in the same area where i had it in the first place!! all my work right down the tubes!! WTF, at least a few other words came out!
But now for the good news, i found the leak pretty easy...it was coming from the end of the rail, where the 9th injector would attach. I just have a plug there, since it was pulled long time ago.
So now for my 2nd mistake, never thought to pull that seal plug out, the WHOLE time i had the rail on my workbench, just sitting there waiting for injectors and whatnot!! all i had to do was wrench it off, and voila, bad O-ring! so that was my problem the whole time...no other seals even looked that bad.....check out my pics.......i show the plug and defective o-ring, next to the original fitting for the 9th injector....
so what to do, use the original o-ring, or try to get a new one from someone?

Fred SS

iTrader: (3)

Buy yourself a Viton O-ring assortment kit. Available at auto parts stores, Ebay, even Harbor Freight has o-ring kits. When I did my TPI conversion, I deleted the cold start injector. So I bought a Cold Start delete kit from a well know company. The plug that screws into the end of rail looked fine except the o-ring was way too big. No way that o-ring was going to fit into the rail. If I tried, it would have been destroyed and cause a leak. So I got a Viton O-ring kit from an auto parts store and found a suitable o-ring in the kit that fit fine. Been there for at least 3 years, no problems (knock on wood, please).

MikeT 88IROC350

Thats a great idea!! Actually, i saw this response earlier today at work, but did not respond till now. Went to Chevy dealer after work, found a p/n for the Oring, but no stock, wasnt discontinued, but said it would be $28 to order, and no guarantee. So went to my local AAuto, and got a generic Oring kit. Not sure it is Viton, but says "SAE" on pak. Sales guy helped me pick one out that should work. Nice and fat ring, snug fit. Also found one at work in tool room, was thinner and fit a little loose in the groove. Not sure if that one was fuel rated.

So tonight put in the new AA fat ring, on my plug. Not sure i like the fit in the rail, since it squeezed down and didnt really go fully into the rail. Check out the picture, maybe see around the edges the black ring. No leaks tho, had good pressure, and it held good after key off. I can get to this plug again if i have to without much pain.
My 9th injector was disabled in March of 2001, then completely pulled in Feb of 2002. I started doing my own PROMs in 2001. Not sure where i got the plug kit either. But i do know that i have had the fuel rail off, and injectors out for service since. The service i just did, was the 3rd time.
Also, FIC did not have the Oring for that cold start injector. Said i should put the injector back in!! no way!

Fred SS

iTrader: (3)

That o-ring is a little too big, may hold for awhile, but I would suggest finding a better fitting o-ring. When your messing with fuel, best to be safe than sorry.

MikeT 88IROC350

Not what i wanted to hear, but you are probably right. I really didnt like how it went into the rail. I didnt drive the car yet, and it is still very low on fuel. Maybe look for another ring, and see if i can change it.

paulo57509

Someone on here was trying to figure out what size o-ring that is.

When you find the correct size you might want to post it up. It should be referenced by a dash number (ex: -103).

MikeT 88IROC350

Tonight went to a local NAPA store, to see what they had for o-rings. He had an assortment, and found a smaller, thinner ring, that fit tight on the plug. He just gave it to me! So tonight i just checked to see if i could get to the back plug without taking anything apart, and i can. I will change it out soon, and see if it fits better.

MikeT 88IROC350

So this is what i did. 2 O-rings!! gotta be better than one! i just didnt like how the outer one in the groove worked. Seems like it would not seal down inside the rail. So used 2 rings that were tight on the plug. And i did not lock it down super tight. Hopefully holds for a long time.

Fred SS

iTrader: (3)

You don't need much for the o-ring to seal properly. For a static seal that size, you would need about .010 inch radial compression minimum.

MikeT 88IROC350

Understand that.....but it leaked before. The oring failed bigtime. Likely due to the ethanol fuel eating it up. So i just figure 2 rings are better than one. I have 48psi on that rail. Drove car today, filled it up with E0-91 oct. What a great feeling to drive it again!