Drove to six miles came home about 2 hours latter tried to start but engine turns over without starting it only has 23,000 miles on it, changed the gas fillter , fuse and relay, test light shows power to relay when key is turned on, no current goes to the pump. checked ground seams o/k, car is in laredo so no humidity to worry about. Mike

 

You might have a bad wire to the fuel pump. Just because you have voltage there doesn't mean you have the current to turn the pump. I know this because I once had a similar problem with a different car. Everything looked good, I even had voltage at the pump. I finally just took a jumper wire and hooked it directly to the pump. The pump ran fine. The fuel pump power wire was buried in a bundle somewhere in the frame, and it had apparently corroded internally. I had 12V at the pump with the wire removed, but as soon as I hooked it to the pump the voltage dropped to zero. So I just ran another wire from the fusebox to the pump. I hooked it up in the exact some spot the existing wire was hooked to, I just bypassed the high resistance in between the pump and the fusebox.

 

Have codes p1111 IAT high voltage and p1230, fuel pump low speed malfunction
> what would be the next step?

 

P1111 is completely normal. You'll always have either a P1111 or a P1000. Those are two normal codes.

For a 1998 XK8, the fault description for a P1230 is "Fuel pump relay malfunction". The possible causes are:

*Fuel pump relay failure
*Fuel pump relay to ECM circuit fault
*Fuel pump relay coil power supply open circuit
*ECM ground circuit fault (relay coil drive)

The first thing to check would be the fuel pump relay. It's in the trunk. lift up the cover over the battery on the floor of the trunk on the right side. You'll see a fuse box. The fuel pump relay is in that fuse box. Here's a diagram:




There are probably other relays in that fuse box that are identical to the fuel pump relay. Try swapping the tail lamp relay or the fog lamp relay, or any relay that fits, for that matter, with the fuel pump relay. You should probably avoid using the ignition positive relay, however. I'm not sure what it does but it sounds important.

If swapping the relay fixes the problem, then you know you need to new relay. If swapping the relay doesn't fix it, then let us know. You probably have a wiring problem of some sort.

 

Hmmm... I'm not sure why that pic was so small. Trying again.



That's better...

 

And if the relay fixes it, LET US KNOW! LOL! I hate to be left hanging.

 

Rev:

I went through much of the same diagnosis, but my problem was just a bad fuel pump. I got the Airtex (Ford) fuel pump, sock filter and fuel filter @ Rock Auto.

Pulling the tank while on jack stands is a real pain, so I farmed the job out.

My local garage picked up my car on a rollback, and they charged the normal 2.7 hrs. labor charge. Come to find out, the mechanic works on Jags all the time.

$50 per hour mechanics and a $65 wrecker charge are a good reason to live in The South. It was well worth $200 to have them pull the tank.

 

The Rev is right on.

The "Fuel Pump Relay Circuit Malfunction" fault code indicates a open circuit in the wiring from the ECM to the Relay Coil, or a open circuit inside the Relay (feeding the Coil). The ECM monitors the current feeding the Relay Coil and if there is no current flowing when the Coil Circuit is energized, the fault is shown.

The current flow to the Fuel Pump itself is NOT monitored. So a bad (Open Circuit) Fuel Pump will NOT trigger a direct Fault.

A bad connection inside the Relay in the (High Current) connection to the Pump itself would also NOT trigger a Fault.

 

Have no current at the pump, replaced the trunk fuse block, complete, the Car sat for 4 Years, so replaced , with a new one still no current to the pump. Mechanic ran an external grd. wire and hot lead direct to the pump, the pump didn't work at all. My code 1230 says "Fuel pump low speed Malfunction" don't know if that agrees with what you sent? but will remove the tank and install a new pump, if that is advisable? the car only has 23, 000 miles as I work overseas. It is the only XK8 in my6 home town and no one wants to work on it here so am doing work with a local mechanic friend, and we need lots of info.

 

Please see my new heading and thanks.

 

Oh nearst Jag dealer is 156 miles from here or they would have had it already.

 

If you go to my page you will find wiring diagrams and a procedure to R&R the fuel pump if you need it. www.jagrepair.com

 

Thanks to everyone for the help, Pictures of tank and description of work needed to replace the pump were helpful.
>Bought a fuel pump from Auto Parts Warehouse for $56 dollars, onsale from$143. they paid shipping. Jag runs great again.
> I learned that the electical circut to the pump is completed at the trunk fuse box via the relay, so checking the fuse and relay will only show they are in operating condition. The pump proper should be operational with an outside 12 volt source.
>No fuel to the filter, can be checked with home made leads to the pump, thus bypassing all the cars circuts.
Wish all thanks again.