Reinstalling MPI back onto a carbed 496 in a 1997 Baja Islander
11-06-2013, 09:57 AM
#11
Thanks for the feedback as it's been super helpful. I've decided to ditch the FI and order a new carb and just enjoy the boat until the thing grenades and then build up a good motor. It came with a 650cfm but needs an 850cfm, so I'll put one on and call it a day. Thanks for the input!
11-06-2013, 11:09 AM
#12
Thanks for the feedback as it's been super helpful. I've decided to ditch the FI and order a new carb and just enjoy the boat until the thing grenades and then build up a good motor. It came with a 650cfm but needs an 850cfm, so I'll put one on and call it a day. Thanks for the input!
The stock tune should be sufficient to get the motor running in a stable manner on a test stand, but it most likely will not be ideal. To get things working properly you would need to have the fuel table and ignition table tweaked. You either pay someone to do it or get the software and do it yourself. You would also need wide band O2 sensor installed to get AFR data.
Lastly you need to know what your current injector size is and calculate the max HP those injectors can carry at 80% duty cycle. If you are deficient in that area you should step up in injector size.
In summary your big cost going EFI are:
1) tuning (software) doing it yourself ($600 ish plus your time and learning curve) or paying someone else to do it ($??????)
2)Wide band gear ($200-400)
3)Injectors ($400-800)
I'm not trying to sway you one way or the other, but it can be done, even by a layman IF you take your time and think things through. The learning curve is steep but I found it rewarding.
11-06-2013, 12:33 PM
#13
I know you've all ready decided to go the carb route but let me give you another data point for the future. You would be able to install all the EFI stuff from the old motor and get it running, even on the stock tune. Regarding distributor installation you would need to set base timing, which is usually around 8 deg BTDC for Merc motors. Setting base timing is easy.
The stock tune should be sufficient to get the motor running in a stable manner on a test stand, but it most likely will not be ideal. To get things working properly you would need to have the fuel table and ignition table tweaked. You either pay someone to do it or get the software and do it yourself. You would also need wide band O2 sensor installed to get AFR data.
Lastly you need to know what your current injector size is and calculate the max HP those injectors can carry at 80% duty cycle. If you are deficient in that area you should step up in injector size.
In summary your big cost going EFI are:
1) tuning (software) doing it yourself ($600 ish plus your time and learning curve) or paying someone else to do it ($??????)
2)Wide band gear ($200-400)
3)Injectors ($400-800)
I'm not trying to sway you one way or the other, but it can be done, even by a layman IF you take your time and think things through. The learning curve is steep but I found it rewarding.
The stock tune should be sufficient to get the motor running in a stable manner on a test stand, but it most likely will not be ideal. To get things working properly you would need to have the fuel table and ignition table tweaked. You either pay someone to do it or get the software and do it yourself. You would also need wide band O2 sensor installed to get AFR data.
Lastly you need to know what your current injector size is and calculate the max HP those injectors can carry at 80% duty cycle. If you are deficient in that area you should step up in injector size.
In summary your big cost going EFI are:
1) tuning (software) doing it yourself ($600 ish plus your time and learning curve) or paying someone else to do it ($??????)
2)Wide band gear ($200-400)
3)Injectors ($400-800)
I'm not trying to sway you one way or the other, but it can be done, even by a layman IF you take your time and think things through. The learning curve is steep but I found it rewarding.
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