When I step on the gas slightly or even up to about 3/4 throttle, my car boggs and seems to be getting no fuel. I have an air/fuel gauge and it gets so lean its not even on the scale. When I get to full throttle, the car acts normal and has plenty of fuel. I replaced my fuel filter, spark plugs, ignition module, distributor cap and rotor,and my throttle position sensor. I dont know what else it could be. Its really starting to **** me off because I cant firgure out what it is. Please help. Thanks

 

Ice,

No error codes?

You took all the fun out of it when you said you installed a new TPS (I was going to suggest a possible dead spot in the TPS).

The only things that come to mind are you MAF and fuel pressure regulator.

At WOT, the MAF is basically ignored and fuel trim is based on RPM and the lookup tables. I can't imagine how, but if the MAF were not changing it's signal output the ECM would basically use some very lean injector pulse rates until WOT was achieved. That should set an error code, but... You can break into the MAF harness and test the output voltage to make sure the signal is varying with RPM and throttle if you think that's a possibility.

As for the regulator theory, there is vacuum applied to the FPR that basically falls off to nothing when the throttle is wide open. If the regulator is hanging up somehow, you should be able to determine that with a fuel pressure reading.

 

there are no error codes. I have speed density tpi so I dont think it is the maf sensor. I think it might actually be the fuel pump. I did a search and people with simalar probmes im having said there fuel pump went shortly after this. I don understand why it would work at WOT though it doesnt make sense to me.

 

im having the same problem with my 88 celebrity (winter car) with a 2.8 v6, it only happens once in awhile and only when the car is warm or when i shut it off and start it again shortly after, only thing is that mine doesnt kick in at WOT, at least i dont think it will, ill try that tmorrow im not sure if i floored it when i had the problem before... not that this is any help i just thought id mention it

 

Ice,

If you suspect a pump, the first thing to do is check the system pressure.