2005 Mercruiser 57 MPI carbon problems rough idle

"I have a 2005 Mercruiser MPI

"I have a 2005 Mercruiser MPI that ran fine a few weeks ago. Let it sit, went to start it up again today after doing a tune up (rotor, cap, plugs). Started it up, won't run sounds like timing is waaay off. Runs find at high RPMS if I can get it up past low RPM. While running it is smoking and tons of cabon build up coming out of the exhaust. Pulled the new plugs (only 20 min. of running time) they are completely black with carbon, but not wet at all. I pulled the fuel filter which was plugged with rust pieces from the old tanks. Pulled the fuel pump and back flushed all fuel lines (not really much in there at all) I do not have a diagnostic to plug into it. Any ideas or similar experiences? Engine is out of boat and has not yet been installed."

sounds like you have some wire

sounds like you have some wires in the wrong locations recheck your spark plug wires and your firing order..

"Thanks for the response, chec

"Thanks for the response, checked all wires, all correct, that was the first thing I checked to make sure the firing order was right."

"Since it sounds like the trou

"Since it sounds like the trouble started after the tune up (tune down?), I would start there.
There is a special procedure for setting the timing on an MPI engine. did you follow this?
I do no have it here since I am at the lake, but someone else on the site may be able to access the info.
How is it the engine is out of the boat, but you are doing all this test running? What did I miss?
Rod"

"I have a pair of engines that

"I have a pair of engines that I am repowering my 31' Tiara with. They are 2005 MPI's that I picked up from a diesel repower. I ran them before the tune up and then after the tune up. It was running fine before the tune up, but just decided to do it because the inside of the cap looked bad and I didn't know the last time it had been done. I did not try to set the timing and would appreciate any help with setting it someone on here might have. Thanks."

"FOLLOW UP: Well I started fro

"FOLLOW UP: Well I started from the beginning today, dumped the fuel system and filter was full of rust and old tank pieces from previous owner. Took apart fuel system, rail, pulled injectors and cleaned all screens on the injectors which were plugged with crap. Reassembled everything and it runs good as new. Thank you to everyone who posted"

"Dirty gas strikes again!!
Go

"Dirty gas strikes again!!
Good to know you got her fixed up; good work.

BTW, on an MPI engine spark timing is completely controlled by the ECM and not adjustable. The only reference point for the ECM is the crank position sensor (CPS), and unless damaged or disonnected, it is pretty foolproof.
Rod"