no spark after timing set change ??

i purchased this old truck to have as a backup vehicle, so it sets most of the time. here is my problem.......

i purchased this truck early summer. i took it to my local mechanic for an oil change, and figured I'd have them replace the dist cap and rotor, and set the timing while they had it.

a few weeks later i was making adjustments to the carb, and found that the vacuum hose going to the distributor wasn't connected. so i hooked it back onto the distributor, and never gave it another thought.

a few weeks back i checked the timing on it, and saw that the harmonic balancer was out of round. it has the rubber ring in the center, and the outer metal ring of the balancer had moved, so it was wobbling as it spun. god knows how long it had been that way, but i decided to replace it.

as i started tearing into the front of the engine, i found that the water pump was leaking, as well as the fuel pump. then i was down to the metal plate in front of the timing gears, and had to replace a gasket behind that. then i found the timing chain was very loose. so i replaced that too.

today i got it put back together, and when i tried to start it, it just turned over and over, and wouldn't start. i found that i don't have spark going to the plugs.

this is where it gets interesting. after putting it all back together, i loosened the hold down bolt on the distributor, and found that the distributor is froze up / rusted, and will not turn. the rotor does turn. so there is no way to adjust the timing. i removed the distributor cap, and found that the shop that i took the truck to earlier had wedged a piece of black tape between the distributor base, and the advance unit, to hold it in an advanced position, obviously to have it run as best it would under the circumstances.

they didn't bother telling me there was a problem with the distributor when i picked it up. they will not get any more of my business !!

so here i set, with all these new parts installed, a distributor that can't be adjusted, and no fire to the plugs.....

what i need to do first, is get the truck running so i can move it. I'm not very educated with electrics.

can someone help me with figuring out where my problem is with not getting fire to the plugs ??

here's what i know so far.....

first, I've removed the tape holding the advance unit. I'm getting power to the + side of the coil. if i have the 3 wire plug that is between the coil and distributor disconnected, i have power through one wire running toward the distributor. if the plug is connected, i believe the power going to the distributor is being grounded out or something, because i loose the power in the wire. this is using my little 12v tester, and me not really knowing what I'm doing......

also when i try to start it, it acts like it almost tries to sputter / start, right when i let off the ignition key ??

any ideas besides shooting it to put it out of it's misery ?????

wow it looks like this forum is slow this time of year.

maybe i can be helped with this question......

the truck still won't start. it just turns over....

i've replaced the coil, the module / brain box on the left fenderwell. it has a newer cap and rotor. i also checked the inline fuses at the starter cylenoid. there fine. the battery connections are good, and the body ground strap is secure.

when i try to start the engine, with the coil wire pulled away a little bit from the top of the coil, i get one nice spark right when i turn the key to start it. then there's no spark as it's turning over. then when i let off the key, i get one more spark.

anyone have any ideas why this is happening ??

Possibly that large wire that runs from the center of the coil to the center of the distributor cap is bad. Have you removed the distributor cap to make sure that the rotor that had been replaced is okay? Just some thoughts. Also it would help if you would tell us what year truck you are working on and which engine it has.

Possibly that large wire that runs from the center of the coil to the center of the distributor cap is bad. Have you removed the distributor cap to make sure that the rotor that had been replaced is okay? Just some thoughts. Also it would help if you would tell us what year truck you are working on and which engine it has.


hi Mechhound, thanks for your reply !!

sorry for not giving enough info in my post...

the truck is a 1977 ford f150. with a 351m or a 400m engine. i haven't been able to determine which engine it is yet. it's a two wheel drive, automatic trans.

yes the rotor is ok, and is turning as it should. after i replaced all the parts listed in my original post, when i went to start it for the first time, it just kept cranking over, and wasn't trying to fire / start.

I've been checking and replacing all that i can think of, and i have the local auto parts store offering suggestions too.

anyways, I'm trying to figure out why I'm not getting fire to my plugs. when i pull the coil wire off the coil, then hold the coil wires contact over the top of the coil, i am only getting a single spark, just when i start to crank the engine over. then i loose the spark, and the engine just continues to spin not getting any fire out of the coil. then as soon as i quit cranking the engine, i get one single spark at the end of the engine turning over.

at this point, i don't think a coil wire good or bad, would affect whether or not I'm getting fire from the coil would it ?? or am i missing something ??

dealing with the electronics on vehicles is certainly not my strong point for sure....

i hope i am explaining this well enough for you to understand.

1 wire should be hot going to distributer. Then 1 going from distributer to coil should be hot all the time with ignition on..The second one going to the coil should get pulses when trying to start the truck.That tells the coil when to send spark to distributer.