F100 Money Pit

this truck has me about ready to giv up and i need help. i have an 80 f100 which originally had an I6 in it. that motor popped a headgasket a while back and i picked up a 302 H.O.full roller with gt40 heads on it for a good price. this past weekend a buddy and i pulled out the I6 and dropped in the 302. Keep in mind that the I6 ran when we pulled it out, hell i drove it for 10 miles before we pulled it in the garage. the problem is now that the 302 is in everything hooked up i cannot get the son of a to spark. itll crank and crank and crank with no problems but will not fire until you let off the key and it will spark ONE time i did some research and tried a couple peoples suggestions. first off the starter solenoid on the truck originally was only a 3 prong(two big ones and one small one) i went to advanced and got a 4 prong and ran a wire from the I on the solenoid to the positive side of the coil. the truck originally did not have that. also i replaced the ignition module and yet again NOTHING. Im at a lapse im confused and im a little pissed about this. i did not expect the obstacles. i have power to both sides of the coil i am 100 percent sure that the dist is correctly in time as ive double checked that. i am at a lapse here and i have noone else to turn to. so anyones suggestions and or advice is greatly appreciated

johnboy250

sounds like you are not in the voltage range. Did you put a different distributor on the 302 other than a Ford. I had a lot of problems switching from form.to.an accel. And a blaster coil I had to get a voltage regulator from MSD. You should check in to that

Good old Bill

Have alot of questions, first one comes to mind is the one and only one spark when key is let off the start position. Two things come to mind, no power to coil in the start mode, and the second, does the rotor turn? What year is the 302 engine?

F100 Money Pit

No johnboy its a stock ford 302 dist with a msd cap a no name red coil from jegs that is within spec when it comes to resistance value ford racing 9mm plugs wires with accel spark plugs and good old bill the rotor does turn and the block is an 86 or 87 i do have voltage to the coil when key is in run. and im pretty sure it had it during sart mode, im going back to my buddys house tomorrow night to do some more checking with a meter

johnboy250

Do you have the distributor grounded.to the block and the distributor coil ground hooked up. Also try your ignition module those things are about wrothless. There are two sides on those and some times one side.only will go out

F100 Money Pit

the red wire is on the positive side of the coil and the green wire is on the negative side of the coil i had my original ignition box tested and it tested good so i replaced it any ways. still nothing. as far as i could see (taking the cap off and looking) the dist. is grounded the next thing im looking into is with the alternator/voltage regulator hook up. im trying to find a wire diagram for an 86 or 87 mustang alternator and a 1980 f100 voltage regulator. God im so frustrated

Good old Bill

If your battery is charged enough to crank the engine, forget the alt/reg stuff at this time, it doesn't charge untill the engine is running. The battery is doing all the work. You need power to coil in start position and of course you need power in the run position. I am all for technology, but this is when old school points and condensor makes it easier to troubleshoot. Power into coil either from start position or run, if it finds a ground thru the points, the field builds up in the primary, points open, field collapses, induces spark in secondary and plug fires. Even tho the electronic stuff replaces the points and condensor, the principle is the same. Use a test light, on + side of coil the light is steady both in start and run position, on the -side the light has to blink or the field in the primary won't collapse inducing spark into the secondary and firing the plug.

F100 Money Pit

Truck runs.. took it to a guy i knew he took out the electronic controlled dist. slapped a points system dist in it and it fired right up and runs like a champ, thanks for all the help that points system will be out this fall and replaced with a msd box, dist and coil.