Hi all:

Once again the gremlins are on the march. We have (2) '91 245 auto's

One is now working fine, but I can not figure out what the issue is the the other:

Any help will be greatly appreciated.

This car is used infrequently as it is used to tow a trailer. It sat for 4-5 months over the winter, but I used a trickle chager on the battery. In the spring I hooked up the battery and it fired right up. I made (3) short trips with the trailer about 7 miles round trip. On the third trip I noticed the fuel level indicator moving up and down. I thoght it might have been caused by shifting fuel as the tank was only about 1/3 full. (My stupidity as I forgot to top off when I parked it months before).

So no problems other than this strange fuel level indicator. I parked the car and left it over the weekend and then on Monday when I need to go to the town dump with the trailer it would not start.

I added 5 gallons of fresh gas and the fuel indicator went up normally. I shot some starter fluid into the intake manifold by the throttle body and it started to take but would not hold indicatiing to me that there must be a fuel problem.

Well this is what I have done without success:

Changed the fuel filter

Changed out the fuel pressure regulator with a new one

Put a new Fuel pump relay in

After serval attempts to crank and start I pulled a plug and it is not wet and does not smell of fuel

Checked that the main fuel pump spins up ( I hear it when the key is turned on)

Took the ECU (working 561)out of the working '91 245 and put it in the problem brick ;;;result no start! But with the working ECU I did not hear the fuel pump start and spin up)

Put the orig 561 ECU back in and the fuel pump starts (I hear it) but car does not start.

Took the new fuel pressure regulator off (under pressure) and got gas under presure!!! whick means thats the fuel pump is working and gas is getting to the fuel rail. (even if the in tank prepump was bad I am getting fuel pressure at the rail) and this also means that the check valve at the main pump is fine. BTW the fuel filter was clean with absolutely no dirt in the fitler or line)

So my conclusion is that the ECU is not getting a signal from ??(somewhere) to send the command to fire the fuel injectors

Qustion: Can a bad CPS cause the ECU not to send firing commands to the injectors? IF the CPS is toast there would be no signal from the Hall effect sensor and therefore the ECU does not know what the firing sequence is.

Any other suggestions? I am getting a noid light to check the injectors but I think it might be the CPS.

I am baffled as I had thought that a working ECU would solve the issue unless of course that the ECU is missing a input signal.

What should I check next?

Thanks