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Loss of power on 1996 454 xl crusaider

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RickH1

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I have a 1996 carver aft cabin with twin 454 xl crusaidres. On a trip back across the lake I started to lose power on the port engine. It lost power to the point that I could not get it above 3,000 rpm. Thinking a filter was clogged we changed out and cleaned all three filters and screens on the engine. The engine starts and runs fine at low rpm and we checked the fuel pressure and it was running at 20 psi. Today while checking the fuel pressure we noticed that the right side of the engine started to get really hot. The engine temp and manifold temp was within range but the riser and rubber exhaust tube was smoking hot. Still can get the power to the engine.

Any thoughts would be appreciated.

Thanks
 
Could be two independent issues or they could be coupled.....

Assuming its a closed cooling system, the temp gauge just indicates the operating temp of the coolant at one spot....the risers and exhaust hose should not be "smoking hot" (though an IR gun will enable you to quantify that observation) - that is likely due to inadequate raw water flow....checking all four elbows/risers/hoses under that same operating condition should yield nearly identical temps...if not, the hot one should be an indicator.

As far as the loss of power, I'd suggest checking the timing advance function...going from memory, that is likely to have the MSTS box....so if the advance is amiss, the cause could be several items...the good news is with 'twins' you have a reference point and a 'free' source of parts for swapping, if needed....
 
makomark said:
Could be two independent issues or they could be coupled.....

Assuming its a closed cooling system, the temp gauge just indicates the operating temp of the coolant at one spot....the risers and exhaust hose should not be "smoking hot" (though an IR gun will enable you to quantify that observation) - that is likely due to inadequate raw water flow....checking all four elbows/risers/hoses under that same operating condition should yield nearly identical temps...if not, the hot one should be an indicator.

As far as the loss of power, I'd suggest checking the timing advance function...going from memory, that is likely to have the MSTS box....so if the advance is amiss, the cause could be several items...the good news is with 'twins' you have a reference point and a 'free' source of parts for swapping, if needed....
Click to expand...

First of all thanks for your input. It is actually an "open loop" system on this particular model. As for the power loss the timing was the next box on the check off list. We did a timing strop on the injectors and both seemed to be functionig properly at the dock.
 
no problem...

for the hot exhaust, it could be a simple as the raw water cooling pump hasn't been serviced in a while...any idea what their service history is?

not exactly sure what you did with respect to the injectors....if you believe they are functioning, we have no reason to doubt it.

Guess we will hear about the timing light use after it occurs...
 
Hello again. As for the intake pumps I have them serviced every year but who knows it's not hard to check the impellers which I will do again. I am also told the timing issue could make one side of the engine run hotter then the other so Monday we will check the timing and see what find. I am told that at 3,000 RPM's not under load the timing should advance 30 degrees. Also we did check the fuel pressue on the rail but again it was not under load and I have been told that it needs to be done under load.

Thanks again
 
FYI I bought this boat in 2003 and it had 175 hours on it, I now have 1445 hours on the engines. It has served me very well over the years and I have been pretty meticulous about the maintenece. I appreciate your input and hopefully me experience will be help for others.
 
I checked and you are correct....the overheat can be induced by late ignition timing.....so they could be coupled....
 
So we put the timing light on today and the timing was 15 degrees retarded on the port engine. Adjust the timing to 10 advanced at 100 RPM and the engine runs great. Question is now, what caused the timing to slip?
 
Hey there RickH1,
Following your progress with great interest. Can you confirm you have a Delco EST distro and you used a shunt plug attached to 12VDC to set the timing ?

FL Panhandle
 
Hi Fl Panhandle

Since I did not do the timing check myself I can only tell you what I obeserved from the mechanic. He used what appeared to be a standard strobe light with a positive and negative power clamps and a blug wire clip over the number 1 plug wire. He then losened the distributor, turned the distributor shaft and the engine smoothed right out. So the speculation is that the modual is bad. We didn't have time to run the boat on the water but they will give it a test run when then go to haul it out for the winter which should be soon. Also made a slight adjustment to the Starboard engine as well.
 
he needs to ensure the advance function is working as timing advance is critical to proper performance....better to make sure the advance is correct and live with the resulting initial timing....and, like MW inferred, you need a timing plug for an EST distributor.
 
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