420SEL Randomly Stalling?

[JamesDean]

Alright everyone,

My mom's 420SEL is evidently having some random stalling isses that I've been unable to reproduce myself.

Initially I thought it was due to a vacuum leak as the car was stumbling a lot when you would give it throttle. I replaced the two air distribution lines, the crossover line and one of the PCV lines. I also replaced the hard vacuum line to the EZL.

Replacing the above solved the stumbling/stuttering problem and the car now drives well (aside from the stalling) and has good power.

Things I've noticed:

The fuel pumps sound a bit louder than what I recall them sounding like when we first got the car. It has some 220,000 on it now.

The spark plugs were last changed around 208,000 (so they have 12,000) on them. As well as a the distributor and rotor.

I do not recall changing the wires. They are BREMI wires right now, and one of my friends was moving the coil wire around and was able to get it to make a purple arc to the ABS bracket. The wires do physically look bad.

My mom said, when it stalled, the cluster went dark, no indicator lights, needles fell to their default off positions. Perhaps that points to the OVP relay failing, cutting power to electronics which drive the cluster.