[Jazzbass]

Easiest way to test the fuel pump is to put a fuel pressure gauge on the left side FI rail on the engine. This will tell you if the pump is working and that it's putting out enough pressure (> 3bar IIRC). If the pump isn't working it could be:

1. Bad pump
2. Bad DME relay
3. Bad DME
4. Bad sensors as Dave indicated

The DME will only turn on the fuel pump when the ignition is on AND either (a) you're cranking the starter or (b) the engine speed > 400 rpm.

If you don't have a fuel pressure gauge, listen for the pump whine when someone is cranking the engine. Alternatively, jumper the fuel pump on using a jumper wire to the bottom of Fuse 2 and Fuse 3 (fuel pump fuse). That'll turn the pump on regardless of the DME or relay. That can help you figure out if it's the pump or the DME.

Make sure all the connectors in the engine bay are good and closed. As discussed earlier in this thread, these connectors like to deteriorate over time. If the speed or the ref sensors (left side of the engine, bolted to the manifold) are undone, that's a problem. Likewise any of the connectors on the main FI parts - throttle body, etc. Sounds like you're good with a meter; almost all of these sensors can be tested. Make sure:

- Throttle position reads fine
- AFM is fine
- Speed sensor resistance is in range
- Position sensor is in range
- Cylinder Head Temp is in range (this is a likely culprit, BTW, esp if you still have the old 1 wire sensor)

I like to test the sensors at the DME connector itself to make sure the entire circuit is functional. BTW, was the spare DME relay you put in new or used?

- Bad coil - test resistance.

My guess? One of these:
- bad fuel pump
- CHT sensor

FWIW, although it wouldn't have helped in this case, hopefully you can see why having a spare DME relay IN THE CAR is a good idea. Nothing worse than paying $$$$ to have your car towed just so you can install your spare $30 relay.