I have a '96 sea ray 230 with 5.7 LX EFI. i pulled the engine to have it rebuilt. Pulled and reinstalled the engine myself. Had the rebuild done by US Engine. Could not get the engine to start. If I manually poured gas into the engine I could get it to "want" to run. I noticed the injectors weren't spraying. After much fustration I took the boat to a marine dealer to figure out and scan the engine. He told me the ECM was bad and had it sent out to check. It needed replaced. He checked the wiring to find the fault but all looked well. No ECM's were found. We decided to switch to a new marine edlebrock carb and we have the engine running. However the tach is off and I cant shift out of gear without turning the engine off. Then it will start up in nuetral.
What could this cause this.

I went from a 1994 efi 502 in my crownline 225 to a carbed setup. I will look at what color the wire is from the efi to run tach. I ran it with out the tach for a week or two. The only downside is that I have no rev limiter in my marine Hei. I just watch for blow outs or catchin air. You will be happy when you dail it in. I will get you a pic or two on the harness that the tach wire would be at.

does it have a switch-style shift interrupter? or did it use the ecm for that? it hangs on the right manifold and is the interface between upper (front) shift cable and lower (rear) cable. if you have it, it isn't hooked up. if not, you gotta get one. look at any carbed merc set-up and you will see it. they are common used as many merc boats have been parted out...

Yes I do have the interupt switch on the right maniflold and it is hooked up. I'll take a look at another merc. Do I need to rewire this to anywhere? Also my tach has gone crazy and the depth gauge isn't working. I'm thinking these are all related.
Thank you!

Check the adjustment of the interupt switch. It has to be perfect to work. It cuts out the ground to the coil for a split second so you can take the Alpha out of gear.

Do a seach and you will find plenty of posts on this topic.

push the interrupt switch while idling. it should shut motor off if you hold it to either side. if not, it isn't working.

shift switch is my first thought too.

Thanks for the ideas.
I had the engine running, and manually moved the switch......the engine kept running. I unplugged the switch and hooked up the volt meter to it. current is going through it, when i manually operate the switch the circut is broken. Leads me to believe the switch is good.
How do I know which wire is ground from the coil? I have four wires at the coil. Two plug ins. Two wires go to the distributor and the others go into the harness which I'm sure went to the ECM.
Do I need to run one of these wires from the switch to the coil ground?

do a search for mercruiser engine wiring diagram here or google. either will find you what you need. you have verified that the interrupter switch doesn't do the job. so it is hooked up incorrectly...