This weekend's Q-Jet Problems
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From: At my Bar drinking and wrenching in Lafayette Colorado
This weekend's Q-Jet Problems
I just finished going through 4 Q-Jets over the weekend, and thought I would list the problems that these 4 "normal" carbs had. Just for your entertainment, here are the problems that 4 carbs had:
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Lars
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- Accelerator pump rod installed in incorrect lever arm location
- Accelerator pump that is not fuel compatible installed in the carb - pump diaphragm swollen and completely seized in the pump bore - accel pump inoperable
- Choke pulloff bleed calibration hole drilled out, eliminating secondary airvalve control
- Float needle clip installed sideways, jamming the float
- Extreme low float level (very lean)
- Incorrect seals installed on the choke intermediate shaft
- Idle mixture screws fully backed out, attempting to compensate for a lean condition with no idle air/fuel control
- Bent linkages, bent throttle lever, and bent throttle shaft
- Missing fuel inlet fitting
- Missing vacuum nipples
- Wrong float installed
- Broken power piston retaining collar
- Missing primary rod retaining spring
- Secondary throttles not closing due to altered throttle linkage, causing fuel to discharge from secondary nozzles at idle – massive rich condition
- Secondary linkage altered to limit secondary opening to ˝ throttle
- Bent secondary throttle shaft
- Sloppy secondary throttle shaft bushings, preventing consistent return-to-idle speed after WOT operation
- Damaged/altered throttle lever, requiring weld repair
- Bent secondary airvalve shaft
- Severe damage and erosion of dichromate finish on all components
- Missing choke cover
- Secondary airvalve tension spring loose and damaged
- Corrosion on all steel surfaces
- Incorrect hardware installed throughout carb
- Extreme low (lean) APT setting
- Accelerator pump diaphragm collapsed - accel pump inoperable
- Incorrect inlet seat installed
- Undersized jets installed
- Choke intermediate shaft seals missing
- Secondary shaft spring disconnected, intentionally disabling secondaries
- Incorrect choke coil lever installed - choke cannot operate
- Upper Idle Air Bleeds filled with epoxy, making idle circuit grossly rich
- Broken secondary metering rod hanger cam
- Bent & destroyed secondary airvalve spring
- Bowl idle vent assembled and installed upside-down - inoperable
- Primary metering jets damaged
- Grossly misbalanced idle mixtures
- Plugged fuel filter
- Defective choke pulloff - spring is too tight, and bleed restrictor has been drilled out making the pulloff inoperable
- Secondary throttle linkage bent & altered to prevent secondary opening
- Bent & binding secondary airvalve shaft
- Defective (bent & altered) secondary airvalve spring
- Wrong power piston spring installed - spring from ball point pen installed
- Stripped needle/seat threads in bowl
- Cracked float bowl
- Stripped fuel inlet threads in bowl
- Choke cover housing screws broken off in choke housing
- Idle air bypass passages plugged with lead plugs
- Incorrect throttle plate installed with undersized idle air bypass bleeds, causing "fuel dribble" from the main discharge nozzles at idle
- Idle air bleeds drilled out oversized, producing a non-correctable lean idle mixture
Lars
Last edited by lars; Today at 01:03 AM.
