91 Deville has seriious fuel delivery issues after warming up. Pedal to the floor produces nothing except what sounds like internal backfire or popping. Car cools down and problem goes away. I've long suspected the fuel pump is headed south but most times I hear it whining so I haven't bothered to drop the tank yet. Now the computer is throwing codes E71 and E44 and the pump isn't whining at all. Thinking about swapping out the map and if that doesn't do it, I'll replace the darn pump. (tank is near empty anyway) O2 sensor is new and I've checked the fuel pressure a while back when the problem first started. Then, no pressure when key to acc but the pressure was fine when started. Anyone else dealt with the map sensor?

wow...i went thorough the same issue..and when it got hot it crapped out on me. GM told me it was a fuel delivey problem...but i didnt think so. they wanted to charge me somthing like $1700 for new injectors though i could have done to myself for less. I kept getting the MAP sensor code for my car i think it was P031 or 32?......replaced that and it did no good at all....after 5 months of HELL it turned out to be the Ignition control module located under the distriubtor cap and rotar. I guess since it is right on top of the engine that explained why when it got hot it would stop working and backfired then started dieseling.