92 Lumina 3.1 having trouble running

The car runs fine while under 30 m.p.h. Once you give it gas, it completely shuts down. We have replaced the fuel pump, fuel filter, air filter, alternator, map sensor, throttle position sensor, engine module, and catalytic converter. The car has been put onto several different machines and no codes are being sent back. Mechanics have said that the fuel injectors, spark plugs, and exhausts are all operating at full function. I am completely out of options. Anyone have any ideas??

You mean it actually dies, or just falls on its face and won't accelerate?

Hey! I see you live in Alton. I'm in St Louis. Could look at it if it comes down to it.

Sounds like you have been being raked over coals by people who don't know what they are looking for so far.

It actually falls flat on it's face. Cruising is fine, but as soon as gas is given, it cuts out. I have had some of the best mechanics look at it. I was never charged by any of them...so I'm only out on parts.

Well, I'd say you need to figure out what system the problem lies with. There are basically 4: Ignition, fuel, feedback (computer or sensor), mechanical (restriction somewhere). When the fuel pump was replaced, a hogged up strainer should have been noticed if it was a problem.

Does your year have a MAF as well as a MAP, or no?

A drive with a fuel pressure gauge connectoed might yeild some clue. A vacuum gauge reading would be helpful too.

If the engine is revved in nuetral does it go flat too, or just under load? How about if you brake torque it and load it up while not moving? I wonder if the VSS has any bearing on this.

Sounds like you've ruled out restriction with the cat and filter changes. Feedback might be a factor, you didn't mention ignition module or crank sensor, although your problem doesn't sound typical of those.

I suppose if the VSS isn't telling it the car is moving, the ECM might cut the throttle, thinking it is preventing a nuetral overrev.

When u start up it is fine, when u have it in neutral it is fine when u give it gas it is good i think it is under load is the prob, the fuel pressure is good and the vac test was good, the fuel pump was bad and it was all checked and the cat was rusted out and we checked the whole ex system and it was fine, so it is just when u give it gas it falls flat what do u think our next step would be?

How old are the plugs and wires? Bad wires are notorious for breaking down under load.

What happens if say, you leave it in second and try to accelerate above the threshold for the point where it falls down? Can it accelerate past it in a lower gear (less load)?

Has anyone checked the fuel pressure regulator for defect?

You can rent a fuel pressure gauge at Auto Zone, I think. Attach it to the service port on the fuel rail, run it up to the windshield and tape it to it so you can see it and drive, watch what it does when it starts to lay down. If the pressure is still within spec, then there is no fuel issue. While you have a gauge on it, the regulator can be checked by clamping the return line with the key on, the reading should remain the same. If the reading jumps way up, the regulator is bad.

When it lays down, is the motor smooth, just refusing to run up, or missing and popping or backfire or anything?

Try to determine by using different gears at different speeds if the problem is load or RPM related.

When it is first started cold, will it accelerate normally?

The reason I ask, the torque convertor lockup will cause a condition they used to call "trailer-hitching" if it refuses to unlock on demand, and feels to the driver as if the engine is trying to pull a heavy load. Doesn't want to accelerate, but will cruise normally. Usually, if the TCC is failing to unlock, the car will also stall hard when coming to a stop sometimes too. You didn't mention anything like that, so I doubt this is the problem.

Anyway, TCC operation is not allowed until the engine is fully warmed up, that's why I asked.

I need vacuum schematics for 3.1 chevy lumina.

My sister's car ('96 lumina 3.1L) seems to do the same type of thing, only intermittently. This car has two crankshaft angle sensors - one which works below 1250 RPM (24X) and one that works above (7X). Since this car always idles good it looks like the 7X sensor could be working interemittently. Check to see if your problem is rpm related - maybe by attaching a tachometer - if so it must be a "feedback" system problem either sensors or the ECM.