Hi-Perf 320 EFI- can I use the shift interrupter for alpha drive?
07-26-2012, 01:10 PM
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Hi-Perf 320 EFI- can I use the shift interrupter for alpha drive?
Howdy boys,
For reasons I won't go into, I'm replacing a Mercruiser MCM 260 (5.7) on an alpha drive with a Mercuiser Hi Performance 320 EFI. I know the alpha won't like the torque, but I'm just trying to get on the water and I won't be slamming the throttle or anything, so I'm not worried about that.
However, the alpha has an shift interrupter switch that interrupts the coil for the clutch in the alpha drive. If you know what I'm talking about, you know how it works, it just shuts off power to the + side of the coil. It's a carbureted engine.
The problem is that I'm putting in an EFI motor. I've done a lot of reading in the forums, and I've read all kinds of stuff about how to deal with this issue- stuff about repgramming chips, finding the 5vdc wire that drops a few cylinders, etc etc... none of it sounds like anything I want to mess with. And, none of it answered my one question - why can't I just do the same thing on an efi motor, interrupt the coil. From what I was reading, that sounded like a no-no. But I was talking to a mechanic today and he said it was no problem at all. Just interrupt the coil the same way it's done on the carbbed engine.
Does anyone know if this is a safe thing to do? Seems like it'd be fine, but I DO NOT want to harm the ECU in any way. This is a 1991 motor and that ECU can't be replaced. And it can't be modified either.
Thoughts?
Thanks!
Stan
For reasons I won't go into, I'm replacing a Mercruiser MCM 260 (5.7) on an alpha drive with a Mercuiser Hi Performance 320 EFI. I know the alpha won't like the torque, but I'm just trying to get on the water and I won't be slamming the throttle or anything, so I'm not worried about that.
However, the alpha has an shift interrupter switch that interrupts the coil for the clutch in the alpha drive. If you know what I'm talking about, you know how it works, it just shuts off power to the + side of the coil. It's a carbureted engine.
The problem is that I'm putting in an EFI motor. I've done a lot of reading in the forums, and I've read all kinds of stuff about how to deal with this issue- stuff about repgramming chips, finding the 5vdc wire that drops a few cylinders, etc etc... none of it sounds like anything I want to mess with. And, none of it answered my one question - why can't I just do the same thing on an efi motor, interrupt the coil. From what I was reading, that sounded like a no-no. But I was talking to a mechanic today and he said it was no problem at all. Just interrupt the coil the same way it's done on the carbbed engine.
Does anyone know if this is a safe thing to do? Seems like it'd be fine, but I DO NOT want to harm the ECU in any way. This is a 1991 motor and that ECU can't be replaced. And it can't be modified either.
Thoughts?
Thanks!
Stan
07-26-2012, 01:28 PM
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Howdy boys,
For reasons I won't go into, I'm replacing a Mercruiser MCM 260 (5.7) on an alpha drive with a Mercuiser Hi Performance 320 EFI. I know the alpha won't like the torque, but I'm just trying to get on the water and I won't be slamming the throttle or anything, so I'm not worried about
that.
However, the alpha has an shift interrupter switch that interrupts the coil for the clutch in the alpha drive. If you know what I'm talking about, you know how it works, it just shuts off power to the + side of the coil. It's a carbureted engine.
The problem is that I'm putting in an EFI motor. I've done a lot of reading in the forums, and I've read all kinds of stuff about how to deal with this issue- stuff about repgramming chips, finding the 5vdc wire that drops a few cylinders, etc etc... none of it sounds like anything I want to mess with. And, none of it answered my one question - why can't I just do the same thing on an efi motor, interrupt the coil. From what I was reading, that sounded like a no-no. But I was talking to a mechanic today and he said it was no problem at all. Just interrupt the coil the same way it's done on the carbbed engine.
Does anyone know if this is a safe thing to do? Seems like it'd be fine, but I DO NOT want to harm the ECU in any way. This is a 1991 motor and that ECU can't be replaced. And it can't be modified either.
Thoughts?
Thanks!
Stan
For reasons I won't go into, I'm replacing a Mercruiser MCM 260 (5.7) on an alpha drive with a Mercuiser Hi Performance 320 EFI. I know the alpha won't like the torque, but I'm just trying to get on the water and I won't be slamming the throttle or anything, so I'm not worried about
that.
However, the alpha has an shift interrupter switch that interrupts the coil for the clutch in the alpha drive. If you know what I'm talking about, you know how it works, it just shuts off power to the + side of the coil. It's a carbureted engine.
The problem is that I'm putting in an EFI motor. I've done a lot of reading in the forums, and I've read all kinds of stuff about how to deal with this issue- stuff about repgramming chips, finding the 5vdc wire that drops a few cylinders, etc etc... none of it sounds like anything I want to mess with. And, none of it answered my one question - why can't I just do the same thing on an efi motor, interrupt the coil. From what I was reading, that sounded like a no-no. But I was talking to a mechanic today and he said it was no problem at all. Just interrupt the coil the same way it's done on the carbbed engine.
Does anyone know if this is a safe thing to do? Seems like it'd be fine, but I DO NOT want to harm the ECU in any way. This is a 1991 motor and that ECU can't be replaced. And it can't be modified either.
Thoughts?
Thanks!
Stan
I had twin 320 EFI'S in a 86 Formula 272 LS....Alpha SS drives. Alphas will live...with care.
Call Marc Berman with BAM in Pompano Beach...he will know and havepart recommendations.
07-26-2012, 06:37 PM
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Yeah I wasn't thinking when I wrote that. I actually have a schematic for this ignition, which shows the white/green wire on the distributor is the one that gets grounded with the switch. I gather that's the tach wire.
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articfriends (06-24-2023)
07-27-2012, 11:49 AM
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