Hey everyone, here's my dilemma. My fiance took our 88 gt to work today.. ran fine, parked it, went to get back in to drive home and wouldnt start, just cranked. Had it towed home and started diagnosing. I discovered there is no spark. So I stared from the coil.. nothing. I pulled the plug off the coil and checked for voltage.. about 9v, I plugged it back in and check again.. 0 volts. I pulled it off again and checked,, 9v.. plug it in.. 0v. This is with the key in the run possition. I had the coil tested at my local auto parts place assuming that the coil was drawing or killing the juice coming into it.. not such luck.. coil tested fine. What could kill power only when the plug is in the coil? Im assuming this is the reason I have no spark. Thanks so much for any and all suggestions!

 

take a plug out of hte head, with the wire plugged on it... and hold it near the header, and have somone crank the car, if it doesn't fire, then work your way back to the wire that goes from the coil to the cap... take hte wire off the cap and hold it above and see if it sparks... if nothing then replace that wire...

 

Ive already done all that. I have determined that the coil is not getting power.. therefore that is my problem. The question is.. why is the harness plug that plugs into the coil (to supply the coil with power) not having any voltage when I plug it in,, only when it is unpluged.

 

proper way to check the coil is back probe the positive side key on engine off, a test light should be ample and then what triggers coil saturation is the stator in the dizzy which produces a pip signal and is transmitted through the tfi which in turn triggers coil to fire the spark...here is the proper way to diagnosis an efi no start:
http://sbftech.com/index.php/topic,588.0.html

 

i had a problem VERY similar to this, dizzy was the problem


try replacing the TFI module, if that doesnt fix it, buy a new distributor

 

Is 9V enough at the coil? In any case, if you feel the problem is with the coil you should probably buy one and put it in to be sure. I got an oem replacement for less than $20

 

^^^ crane P91 Fireball coil. and upgrade to 8mm wires while your at it too, IIRC, with the P91, you need 8mm silicone wires... you'll have plenty of spark, and it wont drop off spark at higher RPMs.

but that is for after you determine if its your dizzy or a bad TFI

 

the stang