Quadrajet Problem Solving > Diagnose a Quadrajet carburetor problem
Rebuilt Carb-Still Gassy
jamesF:
--- Quote ---I feel bad because I probably should have waited before making any posts on this forum because my post is not really about setting up a carb, but instead about troubleshooting a nagging problem.
--- End quote ---
Dont feel bad about that!
You are in fact trying to: "Diagnose a carburetor problem"
;)
batsong:
Thanks, James, for your comments.
I am getting closer to diagnosing this problem. It turns out that my cam may be in wrong.
I'll let you know what happens!
-Gabe
Cliff Ruggles:
One last thing to keep in mind during your troubleshooting and repairs.
Camshafts with a lot of duration and tight LSA's (Lobe Separation Angle) will allow quite a bit of unburnt fuel out the tailpipes. This is due to both the intake and exhaust valves being open at the same time. We can clean up the exhaust by allowing more fuel to be available for a cleaner burn, but it is not always possible to get rid of all the "rich" smell.
You never provided the exact cam specs, or where it was set up for ICL. In any case, a 230 @ 050" camshaft in a 455 cid engine with apprx 9.5 to 1 static compression ratio is going to produce some smell out the exhaust.
It can be minimized by fine tuning the ignition timing and A/F ratio at idle, but difficult to ever completely get rid of the smell.......Cliff
batsong:
Thanks Cliff. That maybe true as the lobe separation on this cam (Crower # 52241) is 112". I am getting wash down the cylinder walls though. The oil smells gassy after only one trip, but will not ignite readily. I have not checked the compression yet.
The car runs great, but it smells like a gas station, as do my clothes after driving it. I set the timing to 36" all in at 2000 rpm. I tried dialing back the fuel pressure, even cutting it off, but there is no change.
I'll get to the bottom of this. I've posted on another forum and researched seating rings, ignition, exhuast valves etc., and it seems to me it's a good car, just that there is something simple I'm missing.
Thanks again! -Gabe
batsong:
Just an update. This morning I went out and took a look in the primary bores while the ngine was idling. I'm getting big drips of fuel from the nozzles and with the slightest provocation, the accelerator pump quirts gas into the chamber. It is very sensitive. If I touch the throttle linkage without changing the rpm's, it'll squirt. Both of these combined is resulting in gas pooling on the throttle plates.
Thanks again, Gabe
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