robin_schouten
New member
I recently own a Chris Craft C
I recently own a Chris Craft Commander 31 (form approximately 1974) with 2 PCM Chevrolet 305 Engines new installed in approximately 1992.
The left engine works fine but the right engine backfires and dies with more than appr.1400 RPM under load. And I cannot make this engine run OK
Since then I have had the Holley carb.completely rebuild. Put in new ignition points + rotor + condenser + cap + spark plugs + coil.
Set the points with a dwell meter on 28 degrees (works better for me than a feeler gauge) and timing 9 degrees BTDC (as in the manual) on flywheel with strobe scope .
The (cold) engine starts immediately runs perfectly smooth on idle but under load it holds back enormously
when I go over 1400 RPM throttle. (no more backfires after working on the ignition)
If I quickly reduce throttle (under 1000 RPM) the engine will return to normal if i keep the same or higher throttle the engine dies completely
I have checked the ignition (with the strobe scope lamp) and the plugs are still firing when the engine dies
I also mounted the carb. from the good working engine and the problem was still the same. (so rebuild carb. is good).
There is a clear tube on the fuel pump but there is no fuel in it so I think this is working ok..... Could be broken....
I bypassed the fuelsystem by using a small fueltank straight onto the fuelpump. No difference.
I still think that it is a fuel problem but I don't know what to do anymore.
The last thing i can think off is swapping the pump from the other engine or measuring the fuel pressure of the pump.
Does anyone have any other suggestions for me?
I recently own a Chris Craft Commander 31 (form approximately 1974) with 2 PCM Chevrolet 305 Engines new installed in approximately 1992.
The left engine works fine but the right engine backfires and dies with more than appr.1400 RPM under load. And I cannot make this engine run OK
Since then I have had the Holley carb.completely rebuild. Put in new ignition points + rotor + condenser + cap + spark plugs + coil.
Set the points with a dwell meter on 28 degrees (works better for me than a feeler gauge) and timing 9 degrees BTDC (as in the manual) on flywheel with strobe scope .
The (cold) engine starts immediately runs perfectly smooth on idle but under load it holds back enormously
when I go over 1400 RPM throttle. (no more backfires after working on the ignition)
If I quickly reduce throttle (under 1000 RPM) the engine will return to normal if i keep the same or higher throttle the engine dies completely
I have checked the ignition (with the strobe scope lamp) and the plugs are still firing when the engine dies
I also mounted the carb. from the good working engine and the problem was still the same. (so rebuild carb. is good).
There is a clear tube on the fuel pump but there is no fuel in it so I think this is working ok..... Could be broken....
I bypassed the fuelsystem by using a small fueltank straight onto the fuelpump. No difference.
I still think that it is a fuel problem but I don't know what to do anymore.
The last thing i can think off is swapping the pump from the other engine or measuring the fuel pressure of the pump.
Does anyone have any other suggestions for me?