Starter engaged while driving

[ScubaSteve]

I'd be interested to figure out what wire is connected to the 'I' terminal (that is hot in run)

From the schematic it doesn't seem the retard wire to the module should be back feeding.

Having it connected at the 'S' terminal is essentially the same as shown.

Though you have to wonder what else has been changed???

There's certainly been a bunch of creative harness modification!

The brown wire is connected from the "I" terminal to the coil down stream of the ballast resistor. This provides 12 volts when cranking to the coil but it is also recieving 8 volts from the ballast resistor when the engine is running.

[ScubaSteve]

Looks like we posted about the same time, and I missed the Painless harness while reviewing the EVTM.

I would put a diode in the coil wire and move the coil, fuel pump and retard wires to the 'I' terminal.

This will solve any backfeed from the coil and leave only the trigger (through the NSS) connected to the Start (relay trigger) terminal.

LOL I think we are posting at the same time. I will be adding the diode to the wires on the "S" terminal but i could also add a diode to the wire from the coil on the "I" terminal and move everything to "I". That would keep it from back feeding and the worst thing that could happen would be my timing would be retarded and no chance for my starter to kick in.

[ArdWrknTrk]

The brown wire is connected from the "I" terminal to the coil down stream of the ballast resistor. This provides 12 volts when cranking to the coil but it is also recieving 8 volts from the ballast resistor when the engine is running.

Right.

So put a diode in that brown wire so it can't backfeed the retard or fuel pump circuits and leave only the 919 wire connected to 'S' on the starter relay.

I think this is the cleanest and most positive way to eliminate your problem.

[ArdWrknTrk]

LOL I think we are posting at the same time. I will be adding the diode to the wires on the "S" terminal but i could also add a diode to the wire from the coil on the "I" terminal and move everything to "I". That would keep it from back feeding and the worst thing that could happen would be my timing would be retarded and no chance for my starter to kick in.

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[ArdWrknTrk]

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Looking at the '86 EVTM I don't see any electric pumps for a 351. Only 5.0 and 7.5l engines.

http://www.garysgaragemahal.com/electric-fuel-pump-control.html

Did you swap engines or eliminate the mechanical pump on the timing case?

[ScubaSteve]

Looking at the '86 EVTM I don't see any electric pumps for a 351. Only 5.0 and 7.5l engines.

http://www.garysgaragemahal.com/electric-fuel-pump-control.html

Did you swap engines or eliminate the mechanical pump on the timing case?

It was originally a 5.0. All of the original fuel pumps and wiring are installed on the truck I'm just triggering the fuel pump relay with a 3 terminal oil pressure switch.

[ArdWrknTrk]

It was originally a 5.0. All of the original fuel pumps and wiring are installed on the truck I'm just triggering the fuel pump relay with a 3 terminal oil pressure switch.

Okay. This is beginning to make more sense now, as a 5.0l would trigger the pumps from the ECM which you don't have.

 

[ScubaSteve]

So I recieved the new Motorcraft ignition module today. I believe the issue that caused the starter to engage was with my ignition module. I still have not hooked up the wire to retard the ignition at start up as the diodes i plan to use have not arrived but I am thinking about not hooking it up at all. The trucks starts very easy hot or cold so I dont realy think I need it. With the new ignition module the engine idles smoother, the throttle response seems better and no more stumble at wide open throttle.

[Gary Lewis]

So I recieved the new Motorcraft ignition module today. I believe the issue that caused the starter to engage was with my ignition module. I still have not hooked up the wire to retard the ignition at start up as the diodes i plan to use have not arrived but I am thinking about not hooking it up at all. The trucks starts very easy hot or cold so I dont realy think I need it. With the new ignition module the engine idles smoother, the throttle response seems better and no more stumble at wide open throttle.

I think you’ve solved the problem, and if you don’t need the retard function then there’s no need to hook it up.

But, you might get even better throttle response with more initial timing, and then you might need the retard function.

[ScubaSteve]

I think you’ve solved the problem, and if you don’t need the retard function then there’s no need to hook it up.

But, you might get even better throttle response with more initial timing, and then you might need the retard function.

I am planning to check and reset my timing this week. The truck is idling a couple hundred RPM higher with the new module and I am thinking that if voltge was shorted to the retard wire inside the module it may have had my timng retarded a little bit all the time. I had the timing set to 13 deg and im curious if its not a little higher now. I had some problem with my timing moving around a few months ago but I thought the distributor may have slipped. so i locked it down a little tighter and marked it with a sharpie. Now im thinking it may have just been the module moving the timing around. I know plenty of people have said it before but if your using DS2 ignition stick with the Motorcraft brand module. You cant trust the parts house brands for this part.