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.

_________________

WHITE WHINE - 1992 SSE Supercharged 236.26 ci (.040 Over) 15.090 at 90.2 MPH on old engine w/ slipping trans & melted O2 sensor - Gen 3 M62 and matching TB, Gen 2 Pully, Zillamotorsports Ported LIM, YT 1.72 Roller Rockers, SII FPR & Injectors, Hypertech Thermomaster chip w/ 160 Thermo, TransGo Shift Kit, Infinity/Pioneer Speakers and 10" Subs, 1300 watts, 140 amp Alternator, Ricepipe CAI w/ heatshield, Pilot Angel Eye Foglights, Clear Corners, '02 17" Chrome Bent 5's, Magnaflow F-Body Muffler and Hi-flo Cat, Ceramic Coated Ported Exhaust Manifolds, Fan Override
2009 G8 GT - Sport Red Metallic, loaded, SOLO Axlebacks, Rotofab Intake, Tuned, autodim mirror, removed intake manifold cover, HSV GTS triple gauge pod, two tone red-hot shifter and HSV SuperSport steering wheel, GXP rear sway bar and diffuser, 3.45 diff and various Camaro suspension bits, LED Taillights

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...