Can anyone tell me why the secondary barrels and the bottom of the airvalve are caked with soot? What causes that, EGR problems?

 

Delicious. Looks like moisture in the gas overwhelmed the anodize on the aluminum.

I've seen such soot on high blow-by engines. It gets into the intake via the PCV valve and coats on the "cool" carb components. Although we think of the air flow going from the atmosphere to the engine only, it is actually a pulsing, and some vapors go backwards.

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82 Berlinetta, orig V-6 car, now w/86 LG4/TH700R4, 2300 stall TC. Ported World 305 heads, Crane PowerMax 2050 cam. ZZ3/4 intake, oil pump, pan & baffle. Accel HEI SuperCoil & module. Hooker 2055 headers, 3" Catco cat & 3" catback w/dual-opposite Flowmaster 80. 2.93 limited slip. Spohn SFCs waiting to be installed. AMSOIL syn lubes bumper-to-bumper. Daily year-round driver. Best ET, speed TBD...
57 Bel Air, my 1st car. '66 396, 9.7:1 forged TRWs, Weiand Action+, Holley 750VS w/4150 conversion, GK 270 cam, Magnum rockers, Jacobs Omnipack, 1-3/4" Hedders & 3" Warlocks, TH400 w/TCI Sat Night Special conv & Trans-Scat shift kit, MegaShifter, 3.08 8.2" 10-bolt w/Powertrax, AMSOIL syn lubes bumper-to-bumper. Idles smooth @ 700 RPM in D. Best 15.02/95.06 @ 5800' Bandimere (corrected 13.93/102.4 @ sea level).

 

So the soot was something wrong with the engine the carb was sitting on? I may be salvaging some parts from this carb, so if it indicates anything wrong with the carb itself, I want to know which parts to avoid .

If the exterior of the carb is any indication, the motor regularly oiled down the engine compartment, too . This is what it looked like before I took it apart:



The carb in the lower left corner was a different Qjet that I rebuilt. Can you believe that one was in the trunk and the other one was on the motor? The only thing wrong with that one was a dead primary choke pulloff and an intermittent TPS. No wonder they junked the car...

[This message has been edited by 99Hawk120 (edited December 13, 2001).]