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My wife's 93 SSEi has a number of issues which I've slowly been working through.

A little while ago I noticed it would occasionally hesitate or lose power for just a second while cruising or accelerating. I also noticed it would lose power completely at heavy throttle application (occasionally even stalling).

I replaced the spark plugs (old ones still looked good), checked the wires, replaced the fuel filter, checked air filter. All appear fine. I am not losing coolant, or losing significant oil. I unplugged the EGR and the occasional hesitation went away, but the power loss at heavy throttle remains. CEL came on after I unplugged the EGR, it was not on before. Otherwise the car runs and drives fine. Temperature (engine or ambient) doesn't seem to have an effect.

Any ideas? I plan on cleaning the MAF when I'm home from work later this week, but other ideas are welcome.

Thanks.

I would bet on a lean condition caused by either a vacuum leak or insufficient fuel pressure under load. Listen for hissing at idle, spray gasketed areas with TB cleaner and listen for changes in idle quality. And test the fuel pressure at idle both with and without the vacuum line attached to the fuel pressure regulator. I think 42 and 47 psi should be about right.

When my fuel pump was dying, it would lose power under heavy throttle like that.

Turns out the problem was just bad spark plug cables. It runs great now...except when it doesn't run at all...

So now I'm working on a new issue, hopefully just the ICM...