Mercruiser 5.7 EFI Injectors not firing
11-10-2021 | 09:14 AM
#11
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From: frankenmuth michigan
11-10-2021 | 09:51 AM
#12
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This has likely all ready been addressed but make sure the battery is good and the starter is spinning the motor fast enough. There is an rpm trigger in the MEFI units that needs to be reached in order to start. 300 rpm comes to mind. Probably not the problem but thought I'd throw it out there.
11-10-2021 | 11:50 AM
#13
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I would like to thank everyone for their input. I don't even have time right now to read all the posts, but as soon as I get some other projects out of the way, (about a week or so)
I will be digging into it again. Thanks everyone!
I will be digging into it again. Thanks everyone!
11-10-2021 | 05:08 PM
#14
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From: On A Dirt Floor
Okay, found this thread where one person looked at the colors of the resistor/choke/filter ? and some looked up its color bandings.
NEED 3.0 Mercruiser Ignition HELP!!!!!!
What do you say some electric /electronic people ?
NEED 3.0 Mercruiser Ignition HELP!!!!!!
What do you say some electric /electronic people ?
11-15-2021 | 11:14 AM
#15
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From: Cape Coral FL
Possible solution
1995 Mercruiser MCM 5.7 Alpha EFI TBI S/N 0F357172
Customer brought boat to me and had been sitting for 2 years without being winterized. Removed engine, all components and reinstalled on new reman block.
Reassembled, tried to start it out of the boat, but the TBI wasn't spraying fuel. Checked fuel pressure, etc, Has good fuel pressure, but injectors not getting pulse signal from MEFI 1 computer.
Hooked up to laptop, no codes. I have checked everything I can think of and I'm suspecting the computer, but my experience has been in the past that suspecting the computer is the lazy way out, and that usually isn't the problem anyway. I had another boat here with a 5.7 setup out of a Volvo Penta, I swapped the mefi 1 computer out just to see if it would spray fuel, still no fuel. Am thinking it shouldn't care whether it is a Mercruiser or Volvo Penta
Now I'm triple guessing whether the computer is bad at all, or whether I'm missing something stupid simple. Trickled gas down throttle body and engine fires right up.
On a side note, the ignition coil is making a weird buzzing sound for about 2 or 3 seconds when key is first turned on, like it's sparking constantly without the engine even cranking over. If I'm not mistaken the computer gets the reference signal from the ignition to fire the injectors, I replaced the pickup coil, coil and sensor on ignition and it still does the same thing.
Any help would be greatly appreciated. Thanks
Customer brought boat to me and had been sitting for 2 years without being winterized. Removed engine, all components and reinstalled on new reman block.
Reassembled, tried to start it out of the boat, but the TBI wasn't spraying fuel. Checked fuel pressure, etc, Has good fuel pressure, but injectors not getting pulse signal from MEFI 1 computer.
Hooked up to laptop, no codes. I have checked everything I can think of and I'm suspecting the computer, but my experience has been in the past that suspecting the computer is the lazy way out, and that usually isn't the problem anyway. I had another boat here with a 5.7 setup out of a Volvo Penta, I swapped the mefi 1 computer out just to see if it would spray fuel, still no fuel. Am thinking it shouldn't care whether it is a Mercruiser or Volvo Penta
Now I'm triple guessing whether the computer is bad at all, or whether I'm missing something stupid simple. Trickled gas down throttle body and engine fires right up.
On a side note, the ignition coil is making a weird buzzing sound for about 2 or 3 seconds when key is first turned on, like it's sparking constantly without the engine even cranking over. If I'm not mistaken the computer gets the reference signal from the ignition to fire the injectors, I replaced the pickup coil, coil and sensor on ignition and it still does the same thing.
Any help would be greatly appreciated. Thanks
10-12-2023 | 02:14 PM
#16
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1995 Mercruiser MCM 5.7 Alpha EFI TBI S/N 0F357172
Customer brought boat to me and had been sitting for 2 years without being winterized. Removed engine, all components and reinstalled on new reman block.
Reassembled, tried to start it out of the boat, but the TBI wasn't spraying fuel. Checked fuel pressure, etc, Has good fuel pressure, but injectors not getting pulse signal from MEFI 1 computer.
Hooked up to laptop, no codes. I have checked everything I can think of and I'm suspecting the computer, but my experience has been in the past that suspecting the computer is the lazy way out, and that usually isn't the problem anyway. I had another boat here with a 5.7 setup out of a Volvo Penta, I swapped the mefi 1 computer out just to see if it would spray fuel, still no fuel. Am thinking it shouldn't care whether it is a Mercruiser or Volvo Penta
Now I'm triple guessing whether the computer is bad at all, or whether I'm missing something stupid simple. Trickled gas down throttle body and engine fires right up.
On a side note, the ignition coil is making a weird buzzing sound for about 2 or 3 seconds when key is first turned on, like it's sparking constantly without the engine even cranking over. If I'm not mistaken the computer gets the reference signal from the ignition to fire the injectors, I replaced the pickup coil, coil and sensor on ignition and it still does the same thing.
Any help would be greatly appreciated. Thanks
Customer brought boat to me and had been sitting for 2 years without being winterized. Removed engine, all components and reinstalled on new reman block.
Reassembled, tried to start it out of the boat, but the TBI wasn't spraying fuel. Checked fuel pressure, etc, Has good fuel pressure, but injectors not getting pulse signal from MEFI 1 computer.
Hooked up to laptop, no codes. I have checked everything I can think of and I'm suspecting the computer, but my experience has been in the past that suspecting the computer is the lazy way out, and that usually isn't the problem anyway. I had another boat here with a 5.7 setup out of a Volvo Penta, I swapped the mefi 1 computer out just to see if it would spray fuel, still no fuel. Am thinking it shouldn't care whether it is a Mercruiser or Volvo Penta
Now I'm triple guessing whether the computer is bad at all, or whether I'm missing something stupid simple. Trickled gas down throttle body and engine fires right up.
On a side note, the ignition coil is making a weird buzzing sound for about 2 or 3 seconds when key is first turned on, like it's sparking constantly without the engine even cranking over. If I'm not mistaken the computer gets the reference signal from the ignition to fire the injectors, I replaced the pickup coil, coil and sensor on ignition and it still does the same thing.
Any help would be greatly appreciated. Thanks
