Engine dies at all speeds?

[Frisco]

I've got an intermittent problem with my 88 Mark VII. (5.0 Speed Density) I recently purchased the car and some days it runs perfectly and other days it won't idle for long or just dies driving at any speed even trucking along at 80mph? It starts back up but . When I am having the problem the tach drops to "O" immediately like I'm losing electrical power to the computer or something.
Rarely the car will not start at all (usually after sitting for some time) and when this happens there is no spark at the high tension lead of the distributor.
I've read the codes which said it's an ignition module problem, checked for power in and out of the EEC relay (ok), checked fuel pump operation (ok), changed the fuel filter, checked fuel pressure a little low at 36psi, replaced the ignition module on the distributor, replaced the coil ( it was a good excuse to install an MSD coil), replaced the ignition wires, checked the operation of the idle bypass circuit (ok).
My next step is to start checking grounds for the EEC and ignition but I'd appreciate any light you guys could shed on my problem? Have you ever seen a magnetic pickup in the distributor go bad?
Thanks,
Frisco

[johnisbubba]

Ive been told that they could but never had one first hand go bad. Sounds like your on the right track. Good luck with it.

[koolkat94]

Check the negative battery cable and see if there is a black connector that hooks the ground to the body. I've seen these cause all kinds of troubles with bad grounds, if so just cut it off and put a round crimp terminal on it and screw it to the body to eliminate the connector.

[Frisco]

Originally Posted by johnisbubba

Ive been told that they could but never had one first hand go bad. Sounds like your on the right track. Good luck with it.

Thanks!

-------- added 0 Minutes and 42 Seconds later --------

Originally Posted by koolkat94

Check the negative battery cable and see if there is a black connector that hooks the ground to the body. I've seen these cause all kinds of troubles with bad grounds, if so just cut it off and put a round crimp terminal on it and screw it to the body to eliminate the connector.

That's easy enough I'll check it out! Thanks a lot

[Frisco]

Originally Posted by Frisco

Thanks!

-------- added 0 Minutes and 42 Seconds later --------


That's easy enough I'll check it out! Thanks a lot

Thanks again for the help! I did check the ground lead with an ohm meter and although in checked good I did recrimp the terminal on the body end of the wire. While the engine was running I was wiggling some wires around (grounds and power wires) when I wiggled the wires at the module on the distributor she died. Once dead I could hear the EEC relay clicking on and off as I moved the wires. I'll take the connector apart and make the repairs. I guess the computer was telling me the truth? Ignition module and or related wiring?
Thanks again for the suggestions,
Frisco

[johnisbubba]

Glad you got it bro, little things can be such a pain in the arse