CONDITION

     PROBABLE CAUSE

     CORRECTION

Hesitation under light throttle: Deadspot & stumble.

1) Vacuum leak somewhere, or hose off or hooked to wrong vacuum fitting.
2) Accelerator pump problems.
3) Float level set very low.
4) Ignition timing retarded.
5) Dirty idle jet or economizer jet.
6) Idle speed set too fast & mixture is too lean (common!).
7) Idle cut-off solenoid not working, or no power to it or no ground to it.
8) Frozen or binding heated air inlet (stuck in full hot or full cold position).
9) EGR valve stuck on or coming on too early (hose on wrong?)

1) Inspect hoses. Route and lead the hoses correctly. Look for leak because of wrong base gasket or it was installed upside down.
2) Inspect and adjust pump stroke, pump plunger, discharge nozzles and check valves. Inspect the accelerator pump, look for swollen pump cup.
3) Set float to factory specs.
4) Set to factory specs. Make sure advancing correctly.
5) Inspect idle jets. Clean as necessary.
6) Richen up the idle mixture, reset idle speed to factory specs, then lastly reset the mixture using the lean drop method.
7) Inspect & fix as necessary.
8) Inspect & fix as necessary.
9) Inspect hose routing to EGR valve & inspect valve. Replace as necessary.

Doggy, runs rough, lots of black smoke at idle.

1) Choke staying closed or partly closed.
2) Slow flooding.
3) Power valve blown (caused by engine spitting back.)
4) No electricity or heat source to choke.

1) Fix choke or heat source.
2) See flooding section.
3) Replace power valve.
4) Fix cause of no heat source or electricity to choke.

Hesitation under heavy throttle: Deadspot & stumbles. May backfire or spitback.

1) Defective accelerator pump.
2) Metering rods or power valve sticking or binding.
3) Vacuum leak.
4) Float level setting very low.
5) Plugged up fuel filter, defective fuel pump, or swollen or kinked lines.
6) Secondary air valve set wrong.
7) Ignition timing retarded.

1) Look for dirt in pump nozzles, swollen cup from bad gas, or check ball missing or stuck.
2) Inspect and correct.
3) Locate leak and correct.
4) Reset to factory specs.
5) Inspect and replace parts as necessary.
6) Check & adjust the secondary air valve spring.
7) Set to factory specs. Check for proper advancing.

Dies coming up to a stop sign, but idles ok.

1) Bad or misadjusted BCDD (if equipped).
2) Bad throttle positioner or bad vacuum source to it.
3) Idle speed and mixture incorrectly adjusted.
4) Loose or defective float pin.

1) Adjust to specs and replace it.
2) Check throttle positioner with a vacuum pump. Replace if defective. Replace any cracked hoses. Make certain that the vacuum hose is connected to the correct pipe on carb or on the thermal switch. Make sure all related pipes have vacuum.
3) Reset to specs using Recarbco
4) Fix or replace the pin.