Car starts and dies immediately, runs bad the few seconds it runs.

Fuel pressure: Zero psi. Verified by pushing on the pintle with a pick. Very very little fuel pressure shot out. And of course, fuel pressure gauge read zero.

Relay: Swithed the license plate/side marker relay with the fuel pump. Still zero psi. License plate still works, so that verifies relay is good.

Fuse: Number 7 Fuse in the trunk. Didn't light up using my testlight. Yes the testlight works. Took the fuse out. Looks good to me.



Conclusion: bad fuel pump? For what it worth, I do hear the rail prime. But only the smallest amount of fuel comes out when pushing on the fuel pintle.

 

Is the yellow fuse 30 amp ?

Check fuse # 16 / 10 amp LH heelboard fuse box . This closes the relay

The FP relay will click on for 4 seconds then click off by design , it will click a 3rd time on when the ECU sees engine rotation




hjs controls the relay

 

Just checked that relay, it is good.

 

caalapsed fuel filter ?

Have you put your finger on the pump relay to feel it click

Even though it may click do you have the 2nd pump relay to swap "

Check the pumps connector for burnt pins

Some XJ8s have a noise suppressor in the pump connector wires

 

I'll check that when I get back home later,today. Thanks!

 

If your car has about 100,000 miles on it, then the pump is likely DEAD!!!!!!!!!!!!!
The pumps seem to last about 100K miles on average.

Plenty of info on fuel pump replacement.

bob

 

It has 120k miles. Based on the history, the pump was replaced about 3 years ago. But yeah I definitely need to check for burnt pins. If all checks out, what pump do you guys recommend?

 

You can do a simple test to check the pump. On the attached picture, the relay pin marking in red is the Jaguar marking, in black is the standard marking. Take the pump relay out and verify that you have 12V present in the socket for pin 3 (30). It is better to test it with a bulb, connected between pin 3 and ground. If this is ok, use two short wires, each with a spade connector at one end, and plug them into relay sockets for pins 3 (30) and 5 (87). Keep the 20A fuse in. With a fuel pressure gauge connected, tie the free ends of the two wires in the relay socket together and see whether you are getting good fuel pressure or not.

 

You can drive the car around this way but as you exit the car will stay on and drain the battery

 

Using a test light, it did light up on the 86 terminal. I do know the pump is getting power. I removed the fuel cap, put my ear in the fuel fill hole. Had my mom turn the key to ON position. Heard the pump pretty clear actually. It just makes the smallest amount of pressure.

 

The socket for pin 86 gets power with the ignition "on", the socket for pin 30 should have power all the time. If you bridge socket 30 to socket 87, you do not need to switch the ignition at all. This will run the pump continuously (as compared to a few seconds with the ignition on) and give you more time to listen and also see if you get better pressure after a bit longer pump run. The commutator of the pump motor (the copper segments on which the motor brushes rest) can get gummed up, from long sitting, and cause the pump to run at much reduced rpm. It is worth trying with letting the pump run for a longer time which may clear the commutator and restore the pump speed.

 

Ok so this is weird. Last Sunday, my dad came to verify that the pump was bad. While attempting to see if it would turn over, it sounded like it had no compression. I was like wtf, it ran fine two days ago. Just did a compression test, now that I had time to. And about 3 or 4 cylinders are zero psi. Highest cylinder went to 90 psi. 2 cylinders went 30 psi and another at 5 psi. Some pics.

 

 

This makes zero sense. But my dad sprayed starting fluid into the TB a few times and the engine finally started and ran great. I'm not trolling you guys or anything. He said this exact problem happened on one of his x308s.

 

With the engine rotating and the CKPS and ECU sees this the # 1 fuel pump relay will get the 3rd click on for the duration of the drive

So that is good along with your relay and pump if you only had the # 1 fuel pump on the normally aspirated engine

With only the key to on position only before start position do you get the r# 1 relay to click on then off after 4 seconds for your initial starting fuel charge ?

With the # 2 fuel pump there is a senerio where the # 2 fuel pump will turn on in the starting sequence other then the normal # 2 / 4000 RPM trigger on

I am not fully aware how this fail to start on # 1 then reverts to # 2 works as you have the car out of configuration like a removed # 1 relay

With the senerio that it's your # 2 fuel pump running your engine you can still have a issue with your # 1 pump not working at all in both the starting fuel charging sequence and engine rotating continence on for the drive

You would have to remove the # 2 relay and listen for the # 1 pump sound with the trunk open depending on your ear quality

 

BORE WASH???

It does even happen with the AJ6/16 from time-to-time and that is NOT a nikasil engine.

bob

 

This is what my dad said as well. Very weird.

 

@Lady Penelope It's a single pump car. I'll have to double check if I get the 4 second click tomorrow morning.

 

I won't be back until Monday afternoon

Put your finger on the relay and feel for the 2 clicks before the 3rd

The clicks verify you have the right commands to the relay but the relay can still be intermittently bad in not contacting for enough current flow to start the pump

Fuel pump relay swapping options ? as long as the same part number like maybe the A / C clutch , Heater water pump , Cabin blower