Faulty damper plate

"I am trying to keep this shor

"I am trying to keep this short and sweet, but I have been going through year long saga of trying to find out why my brand new installed velvet drive tranny rattled and vibrated at idle. First told rough idle issue so had everything possible done to my crusader engine from new plugs, wires, cap, rotor, IAC valve, bench clean injectors, valve job... had tranny pulled and sent to distributor, Marysville Marine, they tested and said tranny good, now I am told that the damper plate appears to be bad... I had bought a new one (heavy duty model) that was installed with the new tranny. Has anyone out there ever gotten or heard of a defective damper plate right out of the box?
What can make a damper plate go bad? I never hit anything or shifted above idle. Is there anything in the lower part of the engine, ie, shaft bearings or such that could be causing this problem?
So much for short and sweet..."

"Scott, actually they very sel

"Scott, actually they very seldom fail. I can only remember replacing one under warranty and that was because it was not tightened properly when the engine was assembled.

Mike Genna at Marysville spent the last 20+ years at Crusader and would be a good guy to talk to if he is back off medical leave."

"Rick,
Thanks for the reply.

"Rick,
Thanks for the reply. They replaced the damper plate and it made a huge difference. No rattle/lash at idle, smooth reverse, but there still is a rattle putting it into forward, and a slight vibration at idle forward that goes away above idle. Last year when the mechanic was concentrating on the engine he said that the fuel pump pressure was low when he checked it on the fuel rail. He didn't think much of it because his computer diagnostic seemed to indicate pressure was ok. He has since became a certified Premier Crusader tech. and has learned that the computer diagnostic program does not diagnose fuel pressure. Given everything else I have done this may be the last thing to do as I have been told that low fuel pressure may cause a rough idle due to lean misfire. The mechanic is unsure whether the fuel pumps used on my engine have a screen that perhaps may be clogged. He said often they have screens and the engine manual never mentions it. I have cleaned the primary fuel filters and replaced my secondary filters as well. Do you know if these pumps have screens, or where I could look to find them.
Thanks again,
Scott"

"Scott,
If you do not have th

"Scott,
If you do not have the proper fuel pressure, it is a problem. Even if it is not causing this problem, is will cause the motor to run lean. Did he mention how much time the engine has run in "Knock Retard" mode?

You didn't mention what engine you have. The MPI engines with the Fuel Control Cell do not have a screen on either the primary or high pressure pump.

The TBI engines do have a screen on the inlet side of the pump."

"Rick,
I will ask him about t

"Rick,
I will ask him about the "Knock Retard" mode. My engine does not have the FCC. It is an 8.2 MPI that was manufactured in 1999 according to the serial number. I believe that was made before the fuel cell came out. I am assuming that if the diagnostic shows that the engine runs in the Knock Retard mode it is running lean indicating possible low fuel pressure?
Thanks again for your advice.
Scott"

"Scott,

Yes, knock mode is

"Scott,

Yes, knock mode is when the knock sensor detects any type of knock and retards the timing in an attempt to keep from damaging the engine. It can be caused by a lean condition or even a bent prop or bad bearing. You have MEFI III which may not log knock retard time, either way, you are best off to simply check the fuel pressure while under load. You should have 44-48 psi at WOT."

"Rick,
Fuel pressure on starb

"Rick,
Fuel pressure on starboard engine is 38 psi at idle and 35 psi at 2000 rpm. Also tested pressure on port engine for comparison and it was 43 psi at idle and 40 at 2000 rpm. Crusader tells me that psi should be between 43 and 45 psi, but they don't tell me if that is at idle under load or what. The needle also fluctuates on the starboard engine and is rock steady on the port. Given the low reading and fluctuation on the starboard engine fuel pump I am in the process of switching out the fuel pump with a new one. May not get this done before this weekend, bad idea to run boat with the present fuel pump?"