If the tach "freaks" when the key is to On/Pos II......I'm still with the ICM testing, guess where the tach gets "its signal" from......

 

faulty ground sounds plausible

 

Thanks guys for all the advice. Really do appreciate it. So poorman, you think I should replace the Ignitor?? How to test? Thanks so much.
silver6gen - where should i look for grounds? Or do you mean a ground in the ignitor?
Thanks guys!

 

1994 - does that year have a handful of ground wires bolted down at the thermostat housing? Check them for being dirty/loose/corroded or something like that.

Many Autozone-type places can test your ignitor - call em to see about that. I think there's a thread about checking it yourself, but I didn't find it right away...?

 

Jax, I'd start by getting out wiring diagrams and checking all grounds associated with the ignition system and specifically the RPM gauge. If that gauge is jumping then it is pointing to a faulty ground somewhere in its wiring.

Start going through the diagrams one by one checking the grounds and then marking them as you check them. Any grounds bolted to the chassis should be taken off cleaned then reattached. Mark on your diagram the ones that you do this to.

 

Guys, the 5th gen's get their "tach signal" from the ICM.......blue wire, there is a "test port" near the underhood fuse panel.

Jim, the main ground for these is on the drivers end of the TB.

So the car won't start, turn the key to on/pos II and the tach starts jumping without even trying to start the car.........no spark to the plugs........

OP- As stated some parts stores will test the ICM's. If it fails their tests or the ones I'm attaching, I'd get one from a junk yard.....aftermarket are hit or miss.

 

Pic two of the system....again why I'm set on testing the ICM and "maybe the coil".

 

good to know thanks poorman

 

Anytime my friend

 

Thanks guys, awesome responses. poorman - Luckily, i used to do some tech work and i can read those diagrams haha, so I just bought a multimeter off ebay. I'll let you know how it goes....