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> BAD Fuel Leak--Watchout with CB ITB's!
wndsrfr
post Nov 29 2011, 02:00 PM
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Running at VIR PCA DE event & had a major fuel leak on my 2316-4cyl with CB ITB's. See "Lifesaver" thread. So, I'm on the back straight chasing a Cadillac CTS-V & coming up the hill & it does a hiccup "pop"--hmmm whasis? Entering the rollercoaster session it's "pop-pop-pop..." so, fist out the window to pit & come in. Fuel pouring out from the driver's side #2 injector fuel rail. The rail had slipped up just enough to allow the o-ring to be bypassed and 43psi was hosing fuel into the engine compartment.
Cause--the single 8mm allen head bolt that holds the rail down against the fuel pressure had slowly worked loose enough to allow the o-ring to get bypassed. This mount (see the pics) with the center mounted bolt is perfectly set up to fail over time. The culprit is stiff fuel lines anchored to the body and engine vibration however small amplified by the length of the manifolds causes torque on the bolt. The lockwasher may actually exacerbate the problem. Remedy may be as simple as loctite, but I'm going to go for something more robust or at least some stiff wire hooks to be sure. Check yours now---not a pleasant experience!


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banger
post Nov 29 2011, 02:15 PM
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Most oem fuel rails have a clip that keeps the injectors in place. This is something you might want to retrofit to the design. Otherwise with only one screw, it may teeter totter until it blows past an o-ring.
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damesandhotrods
post Nov 29 2011, 02:30 PM
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It’s been a few years since I opened an AC43, but the steel braided hose in the third picture is too short. That could be part of the problem.
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hydroliftin
post Nov 29 2011, 02:31 PM
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QUOTE(banger @ Nov 29 2011, 12:15 PM) *

Most oem fuel rails have a clip that keeps the injectors in place. This is something you might want to retrofit to the design. Otherwise with only one screw, it may teeter totter until it blows past an o-ring.


CB Performance shows such a clip in their parts list for about $6 a pop. Part # 7058:
http://www.cbperformance.com/catalog.asp?ProductID=319

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monkeyboy
post Nov 29 2011, 03:29 PM
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I'd also replace those two allens in the picture that hold the fuel rail to the manifolf with drilled and safety wired ones. Then they can't loosen up.
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aircooledtechguy
post Nov 29 2011, 08:33 PM
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QUOTE(damesandhotrods @ Nov 29 2011, 12:30 PM) *

It’s been a few years since I opened an AC43, but the steel braided hose in the third picture is too short. That could be part of the problem.


(IMG:style_emoticons/default/agree.gif)

Replace that fuel line with a longer one and I'll bet the problem goes away. That thing is WAY too tight.
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ArtechnikA
post Nov 30 2011, 05:48 AM
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a 45º hose end instead of the 90 would help too...
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wndsrfr
post Nov 30 2011, 08:23 AM
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Ahhhh........confession is good for the soul & great for getting the car right! I've ordered the CB clips that the PO left out & I was ignorant of (IMG:style_emoticons/default/confused24.gif) , gonna put in a longer line to the FPR to provide more flex & drill/safety wire the bolts.....

Thanks to all for the input!

John
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sean_v8_914
post Dec 1 2011, 08:08 AM
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stiff line is too short and anchored to the body at the reg, as you mentioned. the engine moves, its supposed to move. please fix that line
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