efi wiring
 

I had distributor problems on my 98 Doral cabin cruiser with 5.7 efi mercruiser. I replaced the distributor with a two wire self contained distributor but now the fuel injectors do not spit fuel. I am assuming that there needs to be a connection made to the tach wire to tell the system that the engine is turning over. can somebody help me out with a wiring diagram or knowledge if this is even possible to run together. Thanks in advance

Yep, that was a mistake
First what is your engine serial number?

0L012262. update. replaced the two barrel efi with Edelbrock manifold and 1409 carb. the old tub just won't plane out hardly at all. most of the time it plows at about 15 mph but occasionally I can get it over 20 then it planes out and will run up to close to 30. I know it's a lot of boat for a 5.7 but surely to god it would plane out from the factory. could use bottom paint and the trim tabs don't work but still think should plane out better. any suggestions. we are using a dui distributor also. we timed it at 12 deg at idle.

Thanks for the SN
What issues were you having prior to first replacing the distributor?

Did you set the timing? Also what size and pitch prop. Did it plane out easy before or is this a new to you boat?

It blew a head gasket first. we fixed that then it would plane out decent but developed a problem where it would die after it ran for a half hour or so. It would lose spark then after it cooled it would start and run decent for another 15 minutes and repeat the process. I am a diesel mechanic by trade but haven't messed with gas too much. I bought a new coil and distributor from amazon and replaced it with aftermarket of same style. we never could get it to run after that so decided to just go old school and got a Davis unified ignition coil in cap distributor, Edelbrock intake and carb and installed it. I thought that would be a power upgrade from a two barrel throttle body injection system but so far can't really get the power I need. It is a lot of boat for a 5.7 but Im sure its capable or they wouldn't have put it in from the factory and it did plane out for the short period I had it running correctly.

Yes we set the timing @ 12 deg btdc. I personally did not do it the guys I have working in the shop did it and I know it's a little hard to see because of rust etc. Im not sure on the prop. I did have it running for about a half hour at one point where it would plane out decent and then the ignition failed. It never just jumped out of the water tho.

You have too many variables at this point thats why you are not getting a lot of responses. Anyway I think timing should be no more than 10. Not sure what Ign you have or if it has a knock sensor but if it does at 12 Degress it is probably knocking and a knock sensor would pull power.

There is no knock sensor. it is a single wire coil in cap distributor.

Most factory Vortec headed motors 30* total timing. Most other sbc’s 32* total timg.

edit: making sure you see the word total :)