LT1 Injectors, tiny leak
Thread Starter
Drifting
Joined: Aug 2009
Posts: 1,971
Likes: 243
LT1 Injectors, tiny leak
I'm in the middle of a headgasket replacement project on my 94.
I left the fuel rail connected to the lines and just swung it up and rested it on the windshield (protected by a fender mat). At one point I keyed the ignition on so that I could turn the steering wheel. This of course primed the fuel pump. A few minutes later I happened to look at my injectors which the nozzles were pointing up due to its orientation on the windshield. 5 of the 8 had a small (and I mean few drops) pool of fuel. This is a clear sign that under pressure some fuel is leaking through the injector, though the amount is tiny.
Cause for concern or normal/acceptable?
I can tell you that I do not believe there is a rich condition caused by this. The combustion chambers/valves/spark plugs were all relatively clean - no caked up carbon anywhere. Its always idled smoothly as well.
I left the fuel rail connected to the lines and just swung it up and rested it on the windshield (protected by a fender mat). At one point I keyed the ignition on so that I could turn the steering wheel. This of course primed the fuel pump. A few minutes later I happened to look at my injectors which the nozzles were pointing up due to its orientation on the windshield. 5 of the 8 had a small (and I mean few drops) pool of fuel. This is a clear sign that under pressure some fuel is leaking through the injector, though the amount is tiny.
Cause for concern or normal/acceptable?
I can tell you that I do not believe there is a rich condition caused by this. The combustion chambers/valves/spark plugs were all relatively clean - no caked up carbon anywhere. Its always idled smoothly as well.
Race Director
Joined: Dec 2006
Posts: 10,383
Likes: 4
IMO not a cause for concern, IF your car runs ok, starts ok, and passes smog.
However, the leak could also be a sign of a partial clog that reduces spray pattern effectiveness.
What is FIC charging for Gen III sets now? In the neighborhood of $150?
I know the "while you're in there" syndrome can be an addiction but I would suggest you call Jon.
However, the leak could also be a sign of a partial clog that reduces spray pattern effectiveness.
What is FIC charging for Gen III sets now? In the neighborhood of $150?
I know the "while you're in there" syndrome can be an addiction but I would suggest you call Jon.
Burning Brakes
Joined: Nov 2011
Posts: 841
Likes: 1
I'm thinking you shouldn't have any fuel, I'd change them "while you're there", it don't make sense not to. I believe you're setting youself up for hard hot starts. You said you're not running rich? Maybe not yet. Well, you know what you have to do
Like the rest of us, it just gets ya pissed that you have to go further. It's never ending, but at least your injectors will be done
better now than later.
Like the rest of us, it just gets ya pissed that you have to go further. It's never ending, but at least your injectors will be done better now than later.
Last edited by caddyboy84; May 8, 2012 at 10:16 AM.
Race Director
Joined: Apr 2000
Posts: 15,344
Likes: 4,009
From: Texas
No cause for concern, probably just a little varnish.
If it really bothers you, you can send them off to be cleaned. Another option, once the car is back together, is to run a bottle of Chevron "Techron" through the fuel system. After that tank of gas is nearly complete, run another bottle through.
If it really bothers you, you can send them off to be cleaned. Another option, once the car is back together, is to run a bottle of Chevron "Techron" through the fuel system. After that tank of gas is nearly complete, run another bottle through.
Instructor
Joined: Mar 2012
Posts: 170
Likes: 0
From: NH
Could you have unseated some of the injectors by putting the cover over them? I did sort of the same thing, but my rail was resting on the radiator tank, I must have accidently hit one of the injectors while I was working on the valve cover gaskets and I keyed on to see if I had any leaky injectors while I had the fuel rail out, well one of them went shooting out of the rail and I had a nice stream of gas coming out of the rail after it!
Instructor
Joined: Nov 2011
Posts: 211
Likes: 1
Could you have unseated some of the injectors by putting the cover over them? I did sort of the same thing, but my rail was resting on the radiator tank, I must have accidently hit one of the injectors while I was working on the valve cover gaskets and I keyed on to see if I had any leaky injectors while I had the fuel rail out, well one of them went shooting out of the rail and I had a nice stream of gas coming out of the rail after it!
Thread Starter
Drifting
Joined: Aug 2009
Posts: 1,971
Likes: 243
Just to clarify it is not an o-ring. It is leaking at the nozzle and puddling in the injector. Just a few drops in 5 of the 8. Since it starts, idles and runs fine I'll leave them be. Maybe give it a fuel injector cleaner in the tank. At least LT1 injectors are super easy to replace even on an assembled motor, should I change my mind down the road.
Melting Slicks
Joined: Aug 2008
Posts: 2,082
Likes: 50
From: Palmdale CA
Just to clarify it is not an o-ring. It is leaking at the nozzle and puddling in the injector. Just a few drops in 5 of the 8. Since it starts, idles and runs fine I'll leave them be. Maybe give it a fuel injector cleaner in the tank. At least LT1 injectors are super easy to replace even on an assembled motor, should I change my mind down the road.
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Race Director
Joined: Jun 1999
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From: Merritt Ils Fl
Tiny leak, that's what the captain of the Titanic said. You may get away with running them for a few more miles but I seriously doubt they will improve with time/use. While you have it apart it seems wise to me to replace them now. Maybe a call to Jon at FIC is in order
Intermediate
Joined: Mar 2012
Posts: 37
Likes: 0
I'm thinking you shouldn't have any fuel, I'd change them "while you're there", it don't make sense not to. I believe you're setting youself up for hard hot starts. You said you're not running rich? Maybe not yet. Well, you know what you have to do Like the rest of us, it just gets ya pissed that you have to go further. It's never ending, but at least your injectors will be done better now than later.
Like the rest of us, it just gets ya pissed that you have to go further. It's never ending, but at least your injectors will be done better now than later.