no spark, but there should be

[jeana]

I have an 86 Ranger with 2.9 it cranks but won't start. There is no spark, but when I put a test light at the green wire on the coil connector, it does light up while cranking. My understanding is that you should have spark if that tests well. I've tried a new TFI module- no change. Tried a new coil- no change. I even installed a new hall-effect switch and still nothing has changed. I'm pretty sure there is fuel pressure. I've ohmed out many of the wires on the ign system. However, I don't have a breakout box. I know the rotor is turning, as well. Any ideas all you Ford experts out there? Any more tests I can run without a breakout box?

 

[IMenriched]

Seems like you've covered a lot of things.

try double checking grounds....all of them....even the one under the passenger side (PS) kick panel, where the ECM is. there is also a ground on the rear of the PS engine to the head or block, most likely a orange wire. Double check the connections at the plug in's.... maybe you've got a pin /spade that is pushing back and won't allow for completing the path.

If you put a timing light on the#1 plug wire...does it light up? just checking to see if the plug wires are good...then plugs??

maybe you got a bad Hall effect pick-up coil?? typically if it doesn't get past the distributor cap, it's the hall effect.

there is a molded in-line resistor/compasitor in the wire from the coil to the distrib....make sure that is good

test the TFI's, most parts stores will , min. of 3-4 times, , rule it out anyway. I had one go bad under 50 miles, can't say that is your issue, just because it new doesn't make it good.

 

[jeana]

I did ohm the new module as well as the old one and they were the same. I also ohmed out the spark plug and coil wires and swapped a coil wire for a newer one and that made no change. You think the hall effect switch could be bad straight out of the box? Or the module I tried could have been bad straight out of the box? I don't have a timing light, but do you know any way to test the EEC power relay with a DVOM? I don't have a timing light. I will check the grounds and other things you suggested.

 

[Earl43P]

If the Fuel Pump is running when you turn the key to Run, then the EEC relay is working.

The EEC relay energizes and routes its output power TO the fuel pump relay coil (as well as the EEC).

 

[BlackBII]

I went through this exact same thing on my BII. I checked and replaced everything, coil, TFI, halleffect etc, same as you. The issue turned out to be in the wiring harness, the one going from the TFI to the grey plug ontop of the passenger valve cover, it's only about a foot long. There are a few wires within a grounded 'shielded' sleeve, and mine were shorting out. It's a long shot, but I bet a junkyard would give you the piece of harness for about 2$.

And I am assuming you are positive your getting fuel in the cylinders??

 

[jeana]

I did put a test light on the fuel injector wire at the computer. It blinked as I cranked, and I get fuel shooting out of the valve on the rail. I'm away from the truck, but I will try looking more at the harness.

Thanks for the advice.