Crusader 454 High RPM Issue

[Greg Mrozinski]

Hi there folks. Looking for some insight and help with a problem I have been having with one of my Crusader 454s. Here is the situation. The starboard engine starts and runs fine and strong up to about 3400 rpms and then starts what appears to be missing type thing and rpms begin to fall the more you push the throttle past that point. As you back off the throttle the rpms will return to about 3400 and smooth out but if you try to push it past that the engine will start breaking downing again. This happens both at rest and underway. Engine is in a 1992 Carver, has a quadajet carb and Delco EST inginition system. This is what I have done so far: new plugs, new cap, new rotor, new coil, new wires and new fuel filter. I rebuilt the carbs 2 years ago and they have run fine with no problems. Gas is fresh and clean. Port engine runs fine on the the same gas tank. The only thing left is the fuel pump in my mind but I wanted to ask the experts here. Thanks for your help.

 

[hottoddie]

Re: Crusader 454 High RPM Issue

21 years on the original fuel pump? I'd replace it just due to age and eliminate it as a possible source of the problem.

 

[Greg Mrozinski]

Re: Crusader 454 High RPM Issue

Yeah I got it. I doubt it is the original one but none the less is probably ready for replacing. I did get a new one and plan on replacing it. The only other thing that might be bad is the distributor module and or pick up.

 

[Bondo]

Re: Crusader 454 High RPM Issue

Yeah I got it. I doubt it is the original one but none the less is probably ready for replacing. I did get a new one and plan on replacing it. The only other thing that might be bad is the distributor module and or pick up.

Ayuh,... Odds are it's sufferin' from a Lean condition, as it only falls off at Higher rpms,...

 

[Lyle29464]

Re: Crusader 454 High RPM Issue

If it fails at the same RPM under a load or not I would look at the timing advance.

 

[Greg Mrozinski]

Re: Crusader 454 High RPM Issue

Thanks Bond-O. I plan on replacing the fuel pump so hopefully that will take care of it.

 

[Greg Mrozinski]

Re: Crusader 454 High RPM Issue

Lyle thanks for the input. I am going to replace the fuel pump first and then if that doesn't correct the problem then relook at the distributor pick up and module. Spark advance is automatically controlled since this is an EST system. No moving plates or anything.

 

[Greg Mrozinski]

Re: Crusader 454 High RPM Issue

Update: Replaced fuel pump yesterday. Still doing the same thing. I am going to try and double check the carb. This 3400 rpm point may be right when the secondaries are kicking in and maybe there is a problem there. Stay tuned.