Bypassing stock computer & ignition
04-22-2010, 10:32 AM
#1
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Bypassing stock computer & ignition Ok first off this is for an old ford motor not an LS1 ( i know its a sin to come here with a question about it lol ) . But i figured there are a lot more people here that know what they're doing than a lot of other places, so heres the story.
Its an '84 bronco with a 351w in it, and there are a lot of cut wires under the hood so locating the ones you need is a bitch. It has an archaic ignition computer and such which im not even sure if it works, so my plan is to just bypass it and run an msd ignition module, i dont really care about the rest of the electronics in the truck becuase its going to be an off road/mud truck.
My main question for now is how to locate the positive and negetive magnetic pick up wires that come out of the distributor to hook up into the msd module. Any input would be great, and feel free to post any comments
Its an '84 bronco with a 351w in it, and there are a lot of cut wires under the hood so locating the ones you need is a bitch. It has an archaic ignition computer and such which im not even sure if it works, so my plan is to just bypass it and run an msd ignition module, i dont really care about the rest of the electronics in the truck becuase its going to be an off road/mud truck.
My main question for now is how to locate the positive and negetive magnetic pick up wires that come out of the distributor to hook up into the msd module. Any input would be great, and feel free to post any comments
04-25-2010, 11:10 AM
#2
i'm answering only because i have a 351w in the boat 
i would first ask, why use the original ford distributor? I would just buy a new billet distributor, either pertonix, msd, or mallory. Unless you have a hard on to run a CDI ignition, just get a full distributor with an electronic ignition pickup module, it will simplify everything. then all you need is a coil. Wiring should be very simple. I would put in a 20A ignition relay, don't power the coil directly from the ignition key switch. Wiring is basically 12v battery to key switch bat terminal; key in run position puts power to the ignition wire from key switch back to engine bay and where that wire runs is up to you (or however ford did it). What i would do is run it to a 20+ amp relay under the hood because you can't power everything through the ignition switch, and then one side of the high current side of the relay comes from bat+ or alternator output wire, the other side will go to a bus bar where you can then branch the circuit to feed the ignition coil, have another wire going back to the instrument cluster, another wire feeding other **** that should only be on when key is on such as fuel pump, and so on.
regarding the pickup wires from the old ford distr. i'm not that familiar with it. you might get lucky looking it up in one of the hayne's books at a part store; otherwise pop the cap off and look for the little pickup module and see if just one wire is coming off it, that would be it. but from my limited experience with ford electronics they tend to do things whack.
i would first ask, why use the original ford distributor? I would just buy a new billet distributor, either pertonix, msd, or mallory. Unless you have a hard on to run a CDI ignition, just get a full distributor with an electronic ignition pickup module, it will simplify everything. then all you need is a coil. Wiring should be very simple. I would put in a 20A ignition relay, don't power the coil directly from the ignition key switch. Wiring is basically 12v battery to key switch bat terminal; key in run position puts power to the ignition wire from key switch back to engine bay and where that wire runs is up to you (or however ford did it). What i would do is run it to a 20+ amp relay under the hood because you can't power everything through the ignition switch, and then one side of the high current side of the relay comes from bat+ or alternator output wire, the other side will go to a bus bar where you can then branch the circuit to feed the ignition coil, have another wire going back to the instrument cluster, another wire feeding other **** that should only be on when key is on such as fuel pump, and so on.
regarding the pickup wires from the old ford distr. i'm not that familiar with it. you might get lucky looking it up in one of the hayne's books at a part store; otherwise pop the cap off and look for the little pickup module and see if just one wire is coming off it, that would be it. but from my limited experience with ford electronics they tend to do things whack.
