I have a 93 Lumina with the 3.1 MPFI and it does not have any power I've replaced the fuel filter and pump, module coil packs computer crankshaft sensor and plugs and wires and the car still takes spells to backfire and does not have any power can someone point me in the right direction to get this car running right

 

If it is backfiring, it's ignition. When did this issue start? As in what have you done, and when did it start?

 

Yeah it backfires like it is crosswired the problem started a year ago when my nephew was driving the car and he just gave up and parked it after replacing everything I mentioned earlier and he even replaced the ignition module twice thinking that was the problem I've ran the codes and to begin with it was throwing 2 codes the MAP sensor high voltage code and a code for the spark control and a coil pack was bad so I replaced all 3 and that code is gone but its still showing the MAP code will a bad MAP sensor cause the problems I'm having

 

Is it still backfiring? Check the electrical connection at the map. New parts don't always mean good parts. If it's still backfiring I'd look at plug wires. The map shouldn't cause this issue, but if the voltage is reading high, it could be a rich, or lean fuel mixture, I'm not sure which.

 

Ok that's what is confusing me sometimes it will get too much gas and flood out and then it will be starving for fuel at other times I've checked vacuum lines and found 2 broke and I fixed them which has helped some

 

Is this a 3.1L? The map sensor has been replaced, and you still have the same issue with too rich, too lean fuel ratio?

 

Its the 3.1 code T MPFI the MAP sensor is the only electrical thing that hasn't been replaced

 

I thought it was replaced. Those are about $50.

 

You need to replace the MAP sensor if you haven’t already done so. The next thing to look at is the timing chain. If the timing chain is loose, it could have jumped a tooth or two. Hope this helps.

 

I borrowed a MAP sensor from a buddy's car that runs great and that hasn't helped Leaning toward the chain because the 2 owners before me have had the car since it was new and they can't remember replacing the chain and the car has 300,000 miles