86 ranger no spark

[ohiocowboy1277]

hi all its been a long time since ive been on here but im back and i got a problem my 86 ranger is not getting any spark i replaced the coil , distributer, computer and 3 ignition modules . it ran after the dist was replaced then quit . i went to start it later and nothing would turn over but not start , the next day i tried it again and it started and died after a few mins of running and wouldnt restart had no spark .
here is the strange part i replaced the ignition module with a spare i had laying around and still nothing so i took another one off a car that ran just 1 min before and tried it still no spark . ive checked the coil as well as swapped every part but the dist with known good parts and it has no spark but my coil has power at both pos and neg wires that go to it ? thats what is messing me up ive never seen that before i traced all the wires and they are good so how does it get 12v power to both wires ? i know this is causing my no spark condition but there is no where that the coil wires are shorted so whats going on ? thanks

 

[kimcrwbr1]

Go to the tech library and look up the sections on TFI and EEC-IV It has to be in the distributor or the wires between the coil and computer. so your saying your getting power to both of the coil wires is the voltage lower on the neg side it is back feeding thru the coil thats normal. You will find the proper way to test the distributor pick up and TFI module you might need a schematic to test for shorts or breaks in wire but sounds like a grounding issue being erratic so find all the grounds first take them apart and sand them one at a time test the ignition so you know where the fault is if it is a ground but clean them all good for s&%ts and giggles. battery to chassis, batt to engine, engine to chassis, coil ground and all the computer grounds.

 

[kimcrwbr1]

did you look at the cap and rotor to see if you have spark going to it put a plug in the distributor wire and see if you have spark there.

 

[ohiocowboy1277]

i tested for spark at the coil and there was none so didnt bother checking the distributer. Actually i get 12V to both sides of the coil. strange, usually i dont get stumped on this stuff but this is the only ford i own im more a dodge guy so this ford stuff sometimes boggles me especially the electronic b.s. im more old school carbed stuff but love these little rangers .

 

[kimcrwbr1]

Go to the tech library and scroll down to TFI diagnostics (click) then scroll down to the old testing procedures and follow what they say. what I said you can put a spark plug into the coil wire off the distributor and ground the spark plug and turn the engine over and see if you have spark. You need to start from the beginning when troubleshooting not in the middle so get someone to help you, print out the procedures find out what the power is doing did you check the EEC relay sometimes they act erratic when they get old. Just swapping parts is one way but alot more work and you can ruin good parts if your not careful. Look over the wires and connectors real good burnt or cracked wires are rel easy to overlook. pull connectors apart and look for corrosion and that the pins are all the way in and give them a little shot of dielectric grease when you put them back together. Did you clean all the grounds especially the coil and computer clean and sand them the get them good and tite (take them apart) Dont get stuck on the coil it sounds like it is ok to me your test is wrong. do you get power to both connectors when it is unplugged then you have a problem. negative comes from the dizzy you have power to the coil do you have power to the TFI module on the dizzy key on and start. I might be the pickup in the dizzy if you have power there and tried different modules. make sure you use the heat sink grease whenever you install the module as you can burn it out real fast if you dont. once again use the tech library that is what it is there for guessing will just get you pissed off.

 

[ohiocowboy1277]

kimcrwbr1 i do get power to both wire at the coil with it disconnected . i replaced the dist because the original had so much corrosion in it that the part where the tfi module plugs into inside the dist was rubbing against the little metal part and wore a grove in the plastic and everytime it rained the truck would run like crap because of the dist . also has a new coil new tfi module new plugs and wires . thats what stumps me because the tfi module is getting power with the key on and while cranking . also replaced the computer due a fault code that if i remember right was something to do with the computer not getting voltage from one of the parts dont remember what one but part was good and wiring was good to it so was a computer failure . the only thing i was able to come up with is my dist took a crap but not sure like i said this ford electronic stuff sometimes looses me lol

 

[BogusSVO]

the pip signal genrator may be bad inside the dizzy.. when that goes the truck will not run...

(it will be cheaper to replace the dizzy than install a new PIP)