Author Topic: Quadrajet fuel bowl level and leaking fuel..  (Read 3086 times)

Offline cecil07

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Quadrajet fuel bowl level and leaking fuel..
« on: April 26, 2011, 07:09:32 AM »
Hi there... just wanted to start out by saying i'm new to the forum and so far it has been a weath of info..I've been trying to figure out what exactly is the matter with my quadrajet carb... I resently purchased a used but barely used(lol..ya i know..theres the problem) Jet performance stage 2 quadrajet.. I installed carb on a 455 pontiac engine with some mild  engine up grades... My problem is no matter how how long the engine runs...2 mins..2 secs.... fuel is seeping out  into intake... Now before you say epoxy the plugs... this has been done.... I have even gone to the extreme and taken carb right down to nothing.. and filled bowl with fuel...a little less than half a bowl of fuel... and gas seems to be leaking out primary on passenger side right near the bottom of primary just above where the main body and base would meet... less fuel.. carb stops leaking .. but.. fuel level is too low and car runs out of fuel when getting into secondaries..hesitates, backfires... surges..whats should I do....what can i do?... I seen no cracks... no damage..can't be a float level...any info would be great... If i have left something important out let me know...car idles great when its not having gas run into it.. and if it wasn't for running out of fuel i would probably leave it...

Now I'm pretty new to the quadrajet world.. but I have spent DAYS taking this thing apart, putting back together, reading on internet... and now i'm here... I'm sure its something simple... but i could really use some help as i have exhausted any ideas of what to do

Offline omaha

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Re: Quadrajet fuel bowl level and leaking fuel..
« Reply #1 on: April 27, 2011, 01:13:17 AM »
you need to check the plugs with some airpressure.  spray some soapy water onto the epoxied plugs and shoot the air through the jet orifices. Check both sets of plugs. btw, not all epoxies are created equal, most have agreed on this forum that marine-tex epoxy is the way to go BUT... first tap the plugs holes and insert some type of threaded plug (small set screws work in some cases) and use the epoxy to keep them in place (kinda like thread lock).
Devcon also makes a good epoxy that is fuel resistant.
        Other than the plugs i cannot think of why fuel would be leaking by the pass side primary (unless there are cracks, again, check with soapy water and air pressure.
      another thing could be the fitment of the main body and baseplate but i am wondering how the fuel could do that since the only circuit that transverses the base plate is the idle circuit and it has to go up above the fuel level before it comes back down. (kinda rules that out)
     The accel pump circuit also has a plug on the bottom on the pass side somewhat.....
     (Needle/seat gasket sealing issues??? I dont think so cause it would jus drain back into the line)
Ok, that s all I can think of, hope some of this will help!?? (at least tis a start) good luck!!

Offline cecil07

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Re: Quadrajet fuel bowl level and leaking fuel..
« Reply #2 on: April 27, 2011, 08:16:42 AM »
I noticed on my last tear down... the clip/pin that the float balances on, sits a little higher than the main body... so when the top plate is installed it pushes down and alters the float reading somewhat... i pinched the clip together alittle... so now its atleast flush with the main bowl...will try this out and post back...

Offline cecil07

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Re: Quadrajet fuel bowl level and leaking fuel..
« Reply #3 on: April 29, 2011, 08:56:37 PM »
ok so.. got carb back on..still running very rich.. air jets do very little... as soon as engine is off... fuel vapors rise out of carb.. float level is 3/8...choke is all the way off... any more ideas?...

Offline cecil07

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Re: Quadrajet fuel bowl level and leaking fuel..
« Reply #4 on: April 30, 2011, 07:30:35 AM »
Decided to take carb off and put original carb back on until Cliffs book arrives and I can do some reading....

Offline Schurkey

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Re: Quadrajet fuel bowl level and leaking fuel..
« Reply #5 on: May 08, 2011, 09:27:54 AM »
I noticed on my last tear down... the clip/pin that the float balances on, sits a little higher than the main body... so when the top plate is installed it pushes down and alters the float reading somewhat... i pinched the clip together alittle... so now its atleast flush with the main bowl...will try this out and post back...
I do exactly the opposite.

I deliberately pull the clip apart, so that the air horn presses on the top of the clip and holds it securely in position.

Shouldn't affect the float height at all, the float pivots on the bottom of that clip, which is secured on each end by the main body casting.