setting base timing on a mpi with a jumper wire ???
11-18-2004 | 08:59 AM
#1
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From: Fairhaven, MD.
setting base timing on a mpi with a jumper wire ???
I have a '97 502 MPI. I want to check/set my base timing with a timing light. I thought all I had to do was ground out the ecm with a jumper wire to put it in base timing mode. There is a grey wire with a female bullet connection cliped to the inside of the ecm box. I was told that this is the wire I need to ground. Is it really that simple...I have read a lot of threads on OSO that seem to say I need a scan tool to set my base timing. If I can just use a jumper wire, will it go into base timing mode right away or do I have to rev the engine. Thanks for the help.
11-18-2004 | 03:20 PM
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From: Fairhaven, MD.
Re: setting base timing on a mpi with a jumper wire ???
Come on guys- I thought this was an easy question. Surely someone has set MPI timing before. I want to set my timing tomorrow morning and don't want to screw anything up. Look'in for a little help. thanks-
11-18-2004 | 04:32 PM
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From: frankenmuth michigan
Re: setting base timing on a mpi with a jumper wire ???
I bought the merc timing tool,local marina had it,i think it was 12$ or something. I just unplug timing terminal(mine mounts ahead of computer to a plastic holder and has 2 wires). Warm boat up first,plug tool in,bring motor up around 1000 rpm's and aim the light. I been told you can jumper the timing portal with a paper clip or a wire,my boats already in storage or i'd go look and give you the wire color,Smitty
11-19-2004 | 09:42 AM
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From: KY
Re: setting base timing on a mpi with a jumper wire ???
Don't know the MPI motor (maybe its the same) but on the 500EFI you jump pins A & B on the DTC connector for base timing...set to 8 degrees and you're done.
11-19-2004 | 11:10 AM
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From: Fairhaven, MD.
Re: setting base timing on a mpi with a jumper wire ???
That seems simple enough...jump A and B. What is the single grey wire for??? Inside of the Metal ECM box, the is a small metal clip on the side of the box. It holds a grey wire with a single pin female bullet type connection. It was obviously put there by the factory for some type of easy service or calibration. I had one mechanic tell me to simply ground this wire to set timing but that sounds different than jumping between pins A and B. I've looked in the Mercruiser servise manual but they don't seem to make reference to this wire.
