1990 convertible. About 60k miles.

Car has been sitting in the garage for a few months. Ran fine a few months ago when parked. I went to start it up and it started for about 2 seconds and died. I then tried starting it multiple times and cranking it over for at least 10 seconds without it starting. I shot some starting fluid in through the intake and she will fire right up and then die quickly.

I did not hear the fuel pump come on like I used to when turning the key to "on" so I assumed the fuel pump was bad and installed another one from Racetronix. The new fuel pump also does not come on unless I apply 12 volts directly to the fuel pump wires. I also directly applied 12 volts to the old fuel pump just for fun and it also seems to run fine. Great.....I put in another fuel pump for nothing.

So after more reading (FSM) and searching I applied 12 volts directly to terminal G on the ALDL. Still no luck. No power to the fuel pump.

I then traced the hot wire from the fuel pump (tan with white stripe) which changes color to gray at the rear junction connection. This gray wire travels to the front passenger side of the car near the fuse panel.
I then back fed 12 volts from the fuel pump and can get 12 volts all the way to the gray wire near the fuse panel. So it appears the wiring is fine at least all the way to the fuse panel area.

Next, I swapped the fuel pump relay for another relay and nothing changes.


Sorry for such a long post but I need some help now at this point.

Any ideas or suggestions.

 

I direct wired the fuel pump to 12 volts and have a steady 45 lbs of fuel pressure at the fuel rail. The car still will not start with the fuel pump running and the 45 lbs of pressure. I'm now thinking my ECM might be bad. I don't think I have any noid lights to check the injectors but they must not be getting activated. I can still spray starter fluid in the intake and she will start right up for a couple of seconds.

 

Yes, check the Injector Ohms.

Also, remove the Fuel Pressure Regulator vacuum line and see if there is any fuel in it which indicates a torn diaphragm.

Are you sure you switched the right relay? The one behind the passenger side knee panel mounted underneath the dash frame?







.

 

I did remove the fuel pressure vacuum line already and did not see any fuel coming out. I'm sure I switched the right relay. I removed the passenger seat so I could lay on my back to get to it. For the 1990 there is 3 relays on the left side and 2 relays on the right side of an air duct that is in the middle. It is the relay closest to the air duct (in the group of three). The injectors should be OK. They are rebuilt Bosch III's from Jon from FIC but I will Ohm them anyway. They are a few years old now.

I removed the ECM and took it to Advanced Auto Parts for an exchange.
They will have another remanufactured one tomorrow morning.

Thanks for the reply.

I will post back tomorrow when I get the new remanufactured ECM in.

 

The ECM turns on the fuel pump through the fuel pump relay when it sees DRPs (Distributor Reference Pulses) from the ignition module inside the distributor. Even if that doesn't happen, the oil pressure switch should supply power to the fuel pump after cranking for a while (it turns on at 4 PSI and it takes a while to build up that much pressure).

This diagram is for my '86 and the relay connector letters are different on your car, but it will give you the idea (maybe your FP fuse is open?):



Can you check the timing while the engine is running? If it shows 6° then the ECM is not controlling the timing. The ECM sets the timing to 20° at idle. It takes over control of the timing when it sees DRPs.

The ECM uses the DRPs to synchronize the firing of the injectors to the rotation of the engine. If it doesn't see DRPs then it won't fire the injectors. The ECM also needs to see a VATS signal or it won't fire the injectors.

Is your ECM fuse OK?

 

Thank you so much for suggesting this. The 3 amp ECM fuse was blown. I don't know why I didn't think about checking it. Replaced it with a new one and she fired right up! I also have a new remanufactured ECM in the car now because I had already dropped the old one off yesterday and picked up the new one this am. Thanks again for your help!