My 2000 S-Type 4.0 has a new problem (new to me) Initially, she failed to start and the message "FUEL COMPUTER DATA ERROR" popped up. If i shut the key off and tried again, it would start. Over the couse of several days, it seemed to progress to causing the vehicle to seeem to stall (gauges drop out and vehicle slows) while driving. Now she might start but will stall soon after. At this point, the "FUEL COMPUTER DATA ERROR" message may or may not appear while attempting to start.

I have disconnected the battery for an hour, I have checked the battery (12.5 volts idle, 11.4 volt while cranking) Fuel level is above 1/4 tank. I have tried to check codes and my Actron ABD II Autoscanner says "ERROR" it cannot communicate with the vehicle (I have used it many times on this and other vehicle without any issue) I have tried a handful of other things that i have found here and on other sites and she still sits in the garage!

Any thoughts?

PS; last 6 of VIN: L50663

 

12.5 V @ idle seems low, should be 13.5 to 14.5.
You might be out of fuel in the right side of the 'saddle-tank'.
The electric pump is in the right side and the 'jet-pump' is a transfer pump to put fuel from the left side to the right for the electric pump. If the jet pump fails you could have a 1/4 tank but it will all be on the right. The fuel level sensors are an average between the 2. (1/8 right + 1/8 left = 1/4 total but 1/4 right and 0 left = NO FUEL to the electric pump)
You might try a fuel pressure test to see if the fuel is actually getting to the fuel rail.

It could be a fault in the RECM (rear elctronic control module) as that controls the electric pump.

Could be a network fault between the PTEC (powertrain electronic control) and the RECM.

I'm not familiar with "FUEL COMPUTER DATA ERROR" but failure to communicate with the PTEC is not good.

bob gauff

 

Thanks for the input. I made a poor choice of words on battery voltage. That voltage is with the battery sitting idle, not the car at an idle... Sorry!

I have run through a series of tests and have the following info:
When I turn the key on, the fuel pump relay does not click. If i check the power supply to the fuel pump, with the key on (Pin 1 on the relay) I have no voltage with the key set to "run" However, if i depress the brake pedal, Pin 1 is energized and i hear a click.

Fuel pump diode supply power, is good
Fuse 4 in the primary junctionn box is energized
Inertia switch supply to fuse 4 is good
inertia switch outbound to the diode input is good

Based on all of this, it appears as though i need to replace the inertia switch. If it is bad:
1. could it go out slowly causing the car to be more and more likely to fail starting?
2. Could it couse the message :Fuel Computer Data Error" to appear.

In other words, am i on a wild goose chase hear and should i be looking elsewhere?

Last question: I was going to buy a fuel pressure tester but the auto parts store only has one and it lists some Fordm GM and Chrysler verhicles and that was it. Any idea whether i can buy one at the local auto parts store that fits these?

THANKS!

 

The fuel pump is NOT an on/off pump. The fuel system is a RETURNLESS system and the pump is controlled by a PWM (pulse width modulated) signal. This speeds the pump up for more pressure and slows to reduce pressure. Without a diagnostic computer and fuel pressure monitor you are only guessing at a fuel related problem.

Unfortunately you might need a computer to talk to another computer and then tell you what the first computer said.

There is a fuel pressure sensor on the fuel rail but you might need a Jag compatible computer to use the datalogue feature in the PTEC module.

You could pull the back seat cushion and see if you have power to the pump itself.

Fixing cars is easy if you know the problem. Diagnosing is an art unto itself.

bob gauff

 

I have exactly the same problem 2001 4.0, and it's driving me crazy!