86 2.9 b2 no spark

[cp2295]

Hey there was out beating on the old b2 a while back and she just died on me. Replaced the ignition coil and the coil module (tfi). Still no spark so i gave up, coil has power on the red and green wires, black wire on the side of the coil has ground. Tfi module has power at 2 terminals. The ground wire (controlled by the ecu) is not grounding, i am unsure if im testing it properly, im just checking it on key on, not cranking. Power wire to the ignition coil does not pulse when cranking. If anyone has a wiring diagram that is worth a damn please post a pic! All help is greatly appreciated need to get that thing going again

Just want to make sure im not missing any simple wiring or computer issues before i go ahead and replace the distributor

 

[RonD]

12volts to coil(+) should be steady with key on
The Ground(-) terminal is pulsed to spark the coil

You can test any ignition coil by hooking up a spark plug to its wire and then giving it 12volts and a ground, disconnect the ground and coil will spark, assuming spark plug is grounded, lol.
Every time you ground and unground the coil will spark, ungrounding collapses the Primaries magnetic field which cause secondary to release its built up voltage.
Grounding causes new magnetic field to be created, charging up the secondary coil again

The TFI module is what runs the Ground(-) terminal on the coil, so there should be no other Grounds on that terminal, or coil can't spark, be ungrounded

The Hall effect sensor in the distributor reads the rotor vanes as they pass by, this gives the TFI module its Spark Timing pulses for the coil
In the old days Points were used as the Ground(-) for the coil, they would open and close to Ground and unground the coil as rotor in distributor turned.

Fairly simple setup

Make sure coil has 12volts when cranking, on some older systems there was a different 12v pathway while cranking.
Remove coils (-) wire and hook it to test light or volt meter and battery (+), then crank engine and watch for pulsing voltage/light, this means TFI module is at least grounding and ungrounding the coil

 

[cp2295]

Well figured it out, finally had a day where i could really dive into it. Pulled the distributor out and found the rotor had broken off and taken out the tabs for the pickup coil along the way. Pickup coil was all busted up and loose, threw a new dizzy in it and she fired right up, thanks for the info ron.

 

[RonD]

Good Work

Busted rotor means loose shaft so good you replaced distributor

 

[cp2295]

Good Work

Busted rotor means loose shaft so good you replaced distributor

Only $60 for a reman might as well just replace it, not worth the time to split the distributor apart to replace the pickup coil! Glad to have her running again. Now the fuel pump in the tank is sceeaming at me so gonna need to replace that soon. Anyone know how to swap the low pressure pump out for a hi pressure in tank pump and get rid of the inline one or is it too much of a pain to worry about?

 

[RonD]

Problem is the in tank high pressure pumps were 1989 and up and Ford changed the gas gauge and Sender OHMs in 1989
73-10 Ohms pre-1989 Fords, 73 Empty, 10 Full
16-158 Ohms 1989-up Fords, so reverse of earlier

The low pressure Lift pumps in the tank seem to last much longer than the high pressure pumps, the frame rail or the in-tank versions, so not sure the "simplification" would be worth the trouble, but just an opinion

 

[cp2295]

Problem is the in tank high pressure pumps were 1989 and up and Ford changed the gas gauge and Sender OHMs in 1989
73-10 Ohms pre-1989 Fords, 73 Empty, 10 Full
16-158 Ohms 1989-up Fords, so reverse of earlier

The low pressure Lift pumps in the tank seem to last much longer than the high pressure pumps, the frame rail or the in-tank versions, so not sure the "simplification" would be worth the trouble, but just an opinion

For sure i guess ill just stick with what i got and put a new low pressure pump in it

 

[Grenade]

For sure i guess ill just stick with what i got and put a new low pressure pump in it

Having just done this on mine, you can honestly just yank a fuel pump rebuild kit from NAPA for fairly cheap. Comes with everything you need to swap the actual pump out without replacing the whole assembly and sending unit. Mine even had it in stock.