Donzigo
07-19-2011, 10:33 AM
RE: 1989 Z-33 w 496HO
I have been chasing this problem since last October and I think I have got it fixed. While taking some vistors for a cruise last October, the port engine went into the Guardian mode and I had to idle home. I haven't had large blocks of time since then to fully tackle this problem; but, July 4th that changed and I was able to really get on it. I drained the fuel tank, checked the entire the fuel system, installed new fuel filters, checked the throttle body, exchanged the idle assmbly with the strarboard side engine, exchanged throttle bodies, installed a new cut off switch; and, then I did what I should have done in the beginning. I called a guy with the Smartcraft big computer machine for 496 engines. ( A generous member on this site had allowed me to borrow his Renda machine but that did not have the increased information of the big computer). The guy found the problem in 5 minutes. The machine said that the computer was reading 29 lbs of water pressure from the sensor at the Transmission cooler; and, the pressure at idle should be around 2 to 4 lbs. So, I replaced the sensor for $113 and "bingo" it works fine.
Here's what it looks like and when I bought it, the parts guy at Marine Max said this was a common problem with 496 engines........go figure.
I have been chasing this problem since last October and I think I have got it fixed. While taking some vistors for a cruise last October, the port engine went into the Guardian mode and I had to idle home. I haven't had large blocks of time since then to fully tackle this problem; but, July 4th that changed and I was able to really get on it. I drained the fuel tank, checked the entire the fuel system, installed new fuel filters, checked the throttle body, exchanged the idle assmbly with the strarboard side engine, exchanged throttle bodies, installed a new cut off switch; and, then I did what I should have done in the beginning. I called a guy with the Smartcraft big computer machine for 496 engines. ( A generous member on this site had allowed me to borrow his Renda machine but that did not have the increased information of the big computer). The guy found the problem in 5 minutes. The machine said that the computer was reading 29 lbs of water pressure from the sensor at the Transmission cooler; and, the pressure at idle should be around 2 to 4 lbs. So, I replaced the sensor for $113 and "bingo" it works fine.
Here's what it looks like and when I bought it, the parts guy at Marine Max said this was a common problem with 496 engines........go figure.