Why does engine bog down when I press spray nozzle in?

Have you tried servicing the motor. Fresh air filter, new fuel filter and a fresh spark plug? That will help narrow down what the problem could be.

filter the lumps out of the paint first ( an old stocking is best for that)
thin using the right thinner material
clean the seals around the spray needle

tighten the spark plugs to factory torque...
Park it in the dark and start it up.
spray some glass cleaner MIST over the engine compartment to find the sparks.... and replace that part.

nozzle is clogged try to take a needle and stick in the hole of the nozzle to free whatevers in there

Welcome to FIxYa.com

Make sure base idle (non computed ) is set correct. Check for vacuum leaks while engine is running, with a can of carb spray. Spray on intake manifold and vacuum lines. Engine will bog down or race up if their is a leak.

Regards, Lee Davidian

Thank you for using FixYa,com.

This issue is caused by defective unloader or debris trapped in spray nozzle or faulty gun. Easy to check. Check system with-out spray nozzle. The engine should not labor at all when you depress trigger without nozzle. If it labors/ dies faulty gun, if no labor, install new or clean nozzle (check for correct gpm for machine) and retest. If ok, you are done, if engine labors or dies, reduce pressure by turning pressure knob as required. If reducing pressure has no effect, most likely faulty unloader. Good luck

check the air flow meter operation and rangeing

First check for any cracked pipes leading into the intake manifold If all OK (with no codes showing it probably is OK) try checking the fuel pressure regulator. If you smell fuel from the pressure regulator vacuum side arm (when the vacuum line has been disconnected) it needs to be replaced.

Hi:
The first thing I would do is be certain the nozzle is not partially plugged. If you attempt to clean it be careful not to damage it in any way

Check your fuel pressure it should be between 25-35. If you do not want to test it then just replace it. If you have to spray gas into the throttle body and it runs great when floored then you are not getting sufficent fuel to your engine and that is the fuel pump