Re: Mercruiser 320 EFIs
 

24*- My engines were rebuilt by a builder that builds Busch series small blocks, the only deviation from stock was the balancing and the roller rocker arms. I would pin the throttles for 15 min (lifting for waves of course) at a time with no trouble at all. Of course I put in new oil coolers, new impellers, new t-stats, water pumps...ect pretty much everything brand new including injectors,fuel pumps,and regulators. As far as the blocks go yes they are 4 bolt mains and should be hydraulic roller cam, mine have World products SR heads on them I don't know if they are stock or someone replaced them.
MPI- I have been looking at the F.A.S.T. system it seems like a great set up, very user friendly and with the addition of the wide band O2 sensorit can almost tune itself.

Firewalker- Yes the injectors, fuel pumps, and regulators are Bosch off the shelf items. But thats where it ends from what I've been able to find out the TPS, IAC,Blocking rectifiers,and air temp sensors are Merc specific. This system fires four injectors at once(1-7-4-6 and 2-8-3-5). I tried to replicate exactly what Merc Hi performance put in from the factory with no changes, I did not have very good luck and I set my two aside for now. I did not want to miss anymore of our all too short boating season. I wish I r could find at a reasonable price, the Merc tester (P/N 91-16850 not the aluminum cased model though) for these systems, it would make troubleshooting much easier. After changing to carbed motors I discovered one of my tachs was bad, when I tried to time the new motor. Since you don't need to look at the tach to time the EFI, only ground the red/yellow wire. I did not know the tach was acting up at low rpms. I belive this may have had something to do with the problems I encountered with the port motor.
All in all they do run great when the are set up correctly, and I would like to rebuild and have a go at them again next year.
PS who is Repair in Florida? I could not get anyone to look at these ECUs. Even a company that advertised them on thier web site.
Joe

Re: Mercruiser 320 EFIs
 

www.rapair.com

you will need to talk to Shawn.
If anyone can do it he can.

RT

Re: Mercruiser 320 EFIs
 

Yea thats the place- CDI I've spoken with them... no interest in the 320 EFI ECU even though it was listed in their catalog. Shawn was not very helpful... no flame just the facts.
I got the impression he felt it was obsolete and not worth the effort and $$.

Re: Mercruiser 320 EFIs
 

he can be a bit crankey
I think that with enough pressure he would do it.

Re: Mercruiser 320 EFIs
 

i owned a sonic 30ss with twin 320 efi's. ran in sw on cape cod and were bullet proof. efi uses bosch injectors found over the counter in any auto supply store. basicly a corvette motor from 86-87 marinized. some tend to run rich but maintain the inputs and you've got a screemin small block that puts out.

Re: Mercruiser 320 EFIs
 

wait a minute..sonic 30ss..did you test drive the boat in marshfield, ma? excuse my ignorance on the post.

Re: Mercruiser 320 EFIs
 

Not only did I test drive it, I bought it abought 5 1/2 years ago:D

Re: Mercruiser 320 EFIs
 

you bought it from me. how's everything.

Re: Mercruiser 320 EFIs
 

Pretty good, still running the boat. Did you ever get another?

Re: Mercruiser 320 EFIs
 

good to hear. i bought an edgewater 247 center console with a yam 250 ob from brian at ss drydock. i miss the rush but like to fish. i'll get back into one at some point.