musclemustang94

why would a bad coil make your tach jump around? cuz mine does and mine has the same symptoms, and i lose power at 4000 rpm and my exaust starts making popping noises.

HACKGT350

your tach is run off the coil thats why so when it goes bad it will throw off the readin on the tach

fordguy17

replaced the coil. still the same problem. i checked the cap and rotor for broken points but everything is clean and looks good.

what else could it be? please, i gotta have my car!

thanks everyone!

Swirl

Are all of your header bolts in place? I know one is missing off of mine (damn exhaust leak)

Swirl

fordguy17

yeah all my header bolts are there. i don't have an exhaust leak.

faulty mass air flow? could a vacuum leak cause this?

can anyone confirm that it has to do with the ignition system?

musclemustang94

I was looking on all data today at work to see what sends the tach its signal so that i could see what would affect the tach. since mine bounces around too and runs like that. Did you try changing the PIP? My shop foreman said if your tach is bouncing around you probably have a misfire, i was lookin at my wires and plugs and discovered one resting on my headers and it was burnt through. The end of the plug is all messed up and so is the inside of the wire. I am hoping this is my problem. The pip is the hall effect sensor (cam sensor) in the distributor. I would check that out too.

fordguy17

yeah i think i'm gonna go ahead and replace the wires. none of them are visibly burned but the wire part right before the plug on both ends of the wire is discolored.

the sensor is inside the distributor, where exactly? what does it look like? do i have to remove the dizzy to access it?

your car is sputtering too? let me know what works onit. i can tell you it's not the coil..i just replaced mine...

thanks so much for asking around man! i really apprecitate it!!

NuclearMuscle523

i had the same prob, paid $300 for a mechanic to test drive it, do tests, replace plugs, wires, level carb, timing adjustment, and run more extensive test drives.... problem was..........
wrong octane gasoline.
apparently cheap gas is the right gas

mattdel

i can't believe the coil didn't work. the tach is wired straight to the negative side of the coil, nothing inbetween. hmm...

fordguy17

yea, i was dissapointed..lol.