Hi all, I just bought a 1999 XJ8 project car and gave it the once over. The battery was completely dead and the plugs were all sludgy. I put in a new Battery and changed the plugs. The car sat for quite a while before I purchased it. I have had no luck in getting the car started. I checked the fuel pressure at the fuel rail when I turn the key and I get over 40psi which in my mind means the fuel pump is working. When I had the plugs out a checked the 1st few for spark and the coil overs were working. If I spray starting fluid while cranking down the intake, she fires and then dies which would indicate to me a fuel issue.

I am wondering what else I can try mechanically to test and eliminate. I have moved relays and check the fuel injection and fuel fuses. Can the gas go bad in a few months and cause the car not to start? When I pulled the plugs I did not see a bunch of wet plugs.

Is there a code reader out there able to tell me if the fuel injectors are firing?

I was going to change the filter and drain the gas tank but as I mentioned I did not see wet plugs which if the gas was not good should have coated the plugs.

Please let me know your thoughts. As mentioned I have good pressure at the Shrader valve.

 

My Daughter's Jetta is from Snohomish- small world.

When it cranks, does it crank slow like normal, or kind of fast? Might be cylinder wash, especially if it has sat for awhile.

 

I had the same diagnosis problem with a Ford engine. Everything seemed to be as it should be but no fuel out of the injectors. Mine had set up a little more than you indicate but not one was actually injecting. An $80 professional off the car cleaning solved the problem.

Because I only had a two wire permanent B+ and a PCM controlled pulsing ground to operate the injectors it was obvious that it was an injector problem and not an electrical issue. I have no idea how to test the Jaguar injectors on the car.

. . . and we were through Everett in June.

 

Well I did some more testing last night and now I have no fuel pressure at the Shrader Valve which would then make it a fuel pump issue. I will have to verify this most likely at the fuel filter and power to the pump. I am no hearing anything in the trunk when I turn the key other than the relay clicking.

 

Hi Greenlee63,

The previous owner of the XJ8 I bought had let this car sit for 2 months in her garage during the winter of 2011. Ended up with a dead battery which she had the Jag dealer come out and replace, it still would not start so it was towed to the Jag dealership where they diagnosed that the fuel pump had died, and replaced it.

 

There have been many reports of fuel pumps failing after extended storage.

 

Well I plan on testing the circuits first and then tackle the nasty job of pulling the tank. I will most likely pull fuel filter first just to make sure but I don't hear the pump kicking on when the key is turned anyway.

 

Well, this is a very old thread, but very similar to my problem, so I'm goin to revive. We recently acquired a 97 jag XK8 and the above symptoms are exactly like mine, but I haven't checked pressure at the fuel rail. I'm in the middle of changing the fuel filter now.

The car sat for 2 maybe 3 yrs, so it has been awhile, but if I spray starter fluid in the throttle body it will run during continuous spray, so I think I have good, or mostly good spark.

Since the car sat so long, I am going to go ahead and pump out the fuel, and replace with new. The fuel inside the tank tho looks very clean and clear really, so other than being very old, I don't see other issues with the fuel.

My pump also makes "no audible sound" whatsoever, but it does get 12V at the harness. I also had to put in a new battery. I;m not sure about the pump, but I keep praying it's not that. haha.

I will replace the filter next, then the fuel, and then I want to check the injectors. I had a friend say that he will checks the fuel rail pressure first, and if that's good, then he checks the injectors but pulling them out (leaving them hooked up) and bagging them with a baggie to see if they actually spray fuel. Has anyone out there tried this, is it possible with this model?

 

Might also check the fuel cut off valve in the right (passenger: US) foot well. If the car was bumped, it will trigger the valve. See the drivers handbook

"Originally Posted by Parker 7
"... on a separate note and try first , there is an inertia / crash switch ( kills engine and fuel pumps ) always located on the cars far right by the passenger's right foot that can act up , does not always reset by the rubber button , place a paper clip between the 2 white wires on the 3 wire connector"

 

Another followup... While I had the fuel filter loose, I cranked the engine to see if I got fuel coming out on the input side to the filter, and I didn't really see any change. I noticed that even with the input side disconnected, fuel doesn't flow out, just drips continually, but doesn't come gushing like I expected. Does that make any sense? The tank is about 1/3 full, so I would expect a pretty healthy from just from gravity? Why would I not get that?

 

I meant "pretty healthy flow from just gravity?
"​​​​​​​

 

Because it has to flow though the pump & if the pump let fuel pour through like you expected then it'd have no ability to produce pressure to pump fuel to the engine.

 

Main thing is to place finger on # 1 fuel pump Relay and feel for click closed on key rotation , 3 seconds then click off , than click back on on engine spinning / turning up in starting

The fuel pump relays are " controlled " by a secret small fuse at the rear seat other than the large power fuses in the trunk

# 10 left heelboard fuse box , this fuse may have to have the ignition positive # 2 relay ( in the fuse box ) click closed to power the fuse , there are relay swapping options to test , researching

This control wire path is very defiantly affected by the inertia / crash switch




At the # 1 fuel pump relay the large # 3 socket ( battery power , hot at all times ) to # 5 to the pump motor ( jumper wire option but the pump will run at all times draining the battery )

Is contolled by this small fuse having control power " sitting " on small socket # 1


The relay closes by the engine ECM providing a ground on socket # 2 to close the relay

This socket # 2 can be tested by a common meter as 0 resistance ( pump relay closing ) with no harm to the engine ECM

The socket back on # 1 will blow a replaceable fuse inside the meter if left on resistance position , so check before touching

This ground will be provided for 3 seconds only on key rotation

The ground will come back when the crankshaft position sensor sees engine rotation for the duration of your drive , safety design

There is a specific engine fuel injector relay to allow them to open , you can see it hanging out by itself at the bottom of this pic

 

Of course! Makes complete sense now that I hear you say it. Thanks, at least I have a better understanding of the situation now.

 

Oh wow! This is extraordinarily helpful! Thank you! I will study this and check for relay operation, and I will check that inertia/crash fix -as both you and another have mentioned- although I feel like there is little chance that it should have tripped as I am friends with the previous (2nd owner) and the car was drivable about 2yrs before when it went on "stasis"... It has been parked in their garage since, until they gave it to us, and we have now towed it home.

 

Thanks! will do!

 

Just a small update from the weekend. I was able to drain the old fuel out (being 2 maybe 3 yrs old I figured it simply best to eliminate that potential issue). I also was able to change out the fuel filter under the drivers side - not too much problem (except for the crumbling plastic fuel-line supports which did not cooperate well. The rubber there is in good shape, and I am comfortable I got everything put back into a satisfactory condition).

I'm going to go in maybe today and see if I can run some diagnostics on these relays, and inertia switches and such, and verify they are all healthy. I plan to be very careful about doing anything tho that could hurt the ECM - it seems to be reporting fine. My OBD2 reader does report the following:

P1000: Manufacturer control
P1224: Throttle position sensor B out of test range
P1229: Intercooler pump driver fault
P1224 (a second time): Throttle position sensor B out of test range

So, if anyone can decipher something from that, it would be appreciated. I have the 4.0, do I have an intercooler pump? (Apologies - I am a complete novice at Jaguar.... My other hobby is a 69 Mustang)

 

Here's the car I'm working with. Really great shape, and a beautiful car if ever there was one.

 

With the XK8 the specific relay and fuse #s given are for the 4 door sedan XJ8 but follow the same form

The relay sockets will be the same ( 1 ; 2 ; 3 ; 5 ) but not the car location or fuse location

 

For your 97 XK8

See page 24 and 33 ( NAS ) North American Specification upper left corner

Do you have starter rotation ?

For fuel You would have to put your finger on relay : EMS relay , Fuel Injector relay and Y and feel for click when starting also the fuel pump relay in trunk , fuel pump relay 3 clicks On 3 seconds - Off - On . The fuel pump " control " has a secret fuse Z , and of course the inertia / crash switch reset , this switch has nothing to do with airbags blowing

Fuse Z is # 3 / 5 amp trunk fuse box , this fuse requires the ignition positive relay in the trunk fuse box to click closed

You can jumper the fuel pump relay between socket 3 and 5 to directly power the pump but will drain the battery with keys in your pocket

Use medium gauge wire with blade type wire ends that the auto parts store can put together for you with a kit under the cash register , take the relay for blade size






There is a thing of bore wash that the cylinders have been placed into if the fuel washes the oil film off the cylinder walls ruining compression to start

Can you find the engine tag to see if AJ26 or AJ27 engine ?

X100 97/E FM SHORT