Hi all,

I have a 1996 XK8 that has been off the road and unloved for a few years. After a bit of TLC it was coaxed back to life and (to my surprise) purred nicely and even drove reasonably well.

Chuffed to bits that I could soon see the XK8 back on the road I set about giving it a proper look over and noticed what (I believe is a slight coolant leak) and decided to get it up on ramps so I could look underneath to see where the leak was coming from. No sooner had I got it up the ramps than the engine shut down without warning. It did not splutter like it was starved of fuel more like it shut down as if I'd turned the ignition off!

The car will crank happily but makes no attempt to fire, not even trying.
The car does now have check engine light on
Fuses all checked before anyone asks :-)
I checked for fuel pressure at the Schrader valve on the fuel rail and no fuel pressure at all.
When cranking the engine the tachometer doesn't even flicker. Its my understanding the tachometer relies on either the cam position or crank position sensors to work and if they are not the ECU will shut the fuel pump off. This obviously would coincide with my check engine light.
Another suspect could be a failed fuel pump/blocked line but I'm not sure either of those would throw up a check engine light.

Does anyone have any ideas/suggestions on what to try now? I have tried a couple of OBD2 readers but so far neither have read a error code which is frustrating. Ideally I want to find one the works with the car but that can wait if needed at the moment.

Your help is much appreciated, I really want roof down V8 motoring again soon

Thanks
Fr

 

If the car has sat for a long time it could well be a dying or dead fuel pump.You should be able to obtain a good squirt at the schrader valve.

Try ignition on briefy a couple of times. The pump should run for about two seconds after ignition on to prime the system, then see if any fuel pressure has built up.

There may be other issues, but that's where I'd start. Replace the fuel filter anyway as it's quite likely original.

Where are you located? With a 96, I'd guess UK?

 

Hey I don’t know if this will help but I recently bought a a 1997XK8 with lower miles, but was garaged most of the time. The car came to me with almost a full tank of fuel that I presume was pretty old. Initially, the car ran OK however, that was being light footed on the Excelerator. Once I had title and bill of sale in hand, I hammer down this thing and I got 11 fault codes. Turned out to be the capacitors in the ECU. However, your situation sounds different.
In the simplest terms, mechanical theory, states that an engine needs four things to run. Air, fuel, spark, and of course compression in the motor.
When I got my 11 codes, some of them were for ignition coils, and my motor was running rough. Aside from that I changed the fuel filter and the spark plugs. The spark plugs were definitely old and completely way off recommended gap. The fuel filter was original to the car, and upon removing it the gas that came out of the lines and into my drip pan was half water and half old gas, which smelled like varnish.
If the car cranks over, but won’t start, I’d start with air, the easiest of which to check.
Then move onto fuel, like previous poster stated, if you turn ignition two on then off, then on a few times, it should prime fuel to the motor. A pressure gauge on the Schrader valve can tell you how much fuel pressure you are getting.
If you have good airflow, and sufficient fuel, then move onto spark. Easy enough to check with the proper tool.
If all above checks out, a compression test on each cylinder will tell you if motor is up to par enough to run. If that’s good, and still no start, your issue might be deeper rooted.
If all else fails, pop the intake tube off and have someone crank it over, while you spray a very light spray of starting fluid directly into the throttlebody. Again very very light spray.
If engine doesn’t want to start at all, then bigger problems exist.
If engine starts and stalls, then I would suspect that air fuel or spark is the issue.
if you read around on this forum, you will see many suggestions, but I always start with the simplest i.e. is the battery good and up to par? Is the fuel good?as you know these cars need high octane fuel. Is the air intake restricted at all? Is there a mouse nest blocking the airflow?
Exactly How long has this car sat?
keep trying different scanners mini will read the codes but not clear them. Let us know what you find.

 

Hi all,

Sorry for being a bit quiet; things have been a mental busy with a relocation.

michaelh yes I am based in Norwich in the UK

Some updates on the situation:

I have taken the connector off the fuel pump and put a multimeter across it a) with the ignition off and no surprise no voltage at the connector b) with the ignition on (but not cranking) and shows no voltage.

The question is when the ignition is turned on will the pump be permanently priming the fuel rail (so I should see voltage) or does this only last for a few seconds and therefore I may have missed it between turning the ignition on and making my way back to the boot to pin out the connector?

In my mind the check engine light is indicative of a sensor failure that would potentially shut the fuel pump off and perhaps not be a pump failure itself. This would align with the way it shut down (I was stood right next to it at the time thankfully), it did not splutter or cough at all and simply shut down like I had turned the ignition off.

stevis05 can you shed light on a scanner that works? I have tried three now with no joy which is infuriating at this point.

Thanks for your help guys

Forestred

 

Are the rear fog lamps working? If not, check fuse #3 (5A) in the trunk fusebox. Check also fuse #7 (20A) in the same location.

Check that the inertia switch in the passenger side fascia fusebox hasn't tripped, - press it to reset - although I'm not sure if the car will crank if it has.

The pump should run for approximately two seconds after the ignition is switched on. Probably best to get someone to do the ignition switching while you monitor at the connector.

I use a cheap & cheerful ELM327 clone with Torque on my Android phone.

 

Thanks michaelh

Yeah all fuses are good but will check again tonight as a precaution. I have checked the inertia switch and as far as I can ascertain its ok and like you I doubt it would crank if it had been tripped.

I'll find a willing or otherwise volunteer to turn the ignition on for me while I monitor the meter. If this fails is there any harm in briefly supplying 12v to the pump directly to see if it primes the fuel rail and thereby determining that the problem is elsewhere?

Yeah I have tried a cheap ELM but it won't connect to the ECU - I do hope thats not a sign!!!

 

As far as scanners go I don’t know what will work other than what I’ve read about here in the forum. I have an innovia 3160 or something like that(I forget the exact model) it’s a cheap one from auto zone but it actually did read my engine codes, however couldn’t read the abs or srs codes. My buddy used his scanner that read 12 systems, the ecu, abs, srs, Tcm, ipk, and others. I don’t know what it was but I know it’s an expensive one, a couple thousand dollars I’m guessing. He runs an auto body shop and fixes cars for insurance after collisions so it’s gotta be able to read everything. There’s actually a lot of debate about what scanners work and what don’t. Wish I could help more

 

Yes, you can apply 12 volts direct to the pump & see if the car starts or you have fuel pressure. I'd put a fuse (10-20A) inline with your alternate power source.
You could also bridge the relay contacts.

You can download the Electrical Guide for you car from member Gus' site here:
http://www.jagrepair.com/images/Auto.../jagxk1997.pdf

which may help you.

 

Yeah the plan is not really to get the car started because I believe as soon as I get to the root cause of the no fuel situation it will be purring again; its more to prove or dis-prove the functionality of the pump at this point. If its sensors etc. I can fix those, if its a pump then it means tank out and is a real pain of a job to do and expensive as its a garage job only.

If I am going down the pump route I want to be absolutey certain that its not working before a £600/700 bill.

I had hoped to get a female connector, the same as the one on the loom that plugs onto the pump to make a little flying lead to get onto the pump's pin contacts rather than trying to squeeze through a small gap to half blindly get clips onto the pins and risk damaging them; however; I have been unsuccessful finding a supplier. If anyone knows of someone breaking an XK8 or has spare looms or where I can buy the connector new then please let me know, I do prefer tailored solutions rather than 'hacks' if I can avoid them.

I will have a look at bridging the relay to see what I need to do.

Thanks for your help guys.
Fr

 

Ok so a quick update.

I put 12V to the pump and it whirred away quite happily so I think we can put the failed pump idea to bed now.

Although this was successful in itself it still did not pump fuel through to the injector rail. At the moment the fuel supply is disconnected from the rail whilst I looked at getting to the Cam Position Sensor. I put a container over the end of it hoping to see fresh fuel and nothing arrived.

I am now wondering if the fuel level senor is to be believed and if the car has actually run out of fuel. Although the way it shut down was not symptomatic of a vehicle running out of fuel i.e.no stuttering/lumpy running etc. and I do still have a check engine light on.

Any further thoughts as to what to look at next guys?

Kind regards
Fr

 

Check the fuel filter. It’s on the drivers side under the body in front of the rear drivers side wheel. I just bought a 97 and changed mine and the one on the car was stock/original. It has a holder bracket that has I think two screws holding it to the body, the filter itself is an “inline” one so it’s fairly easy to change. I removed the bracket to body screws, and followed the line in both directions (toward tank and toward motor) and took off the first fuel line holder in each direction for some more flexibility of the line. Using two open end box wrenches disconnect the inlet and outlet side of the line from the filter and remove the filter with the bracket altogether (use a drip pan underneath as small amount of fuel will spill)
once out an 8mm bolt must be removed that clamps the filter into the bracket.
slip a new filter in and replace the 8mm bolt in the bracket to clamp down the filter to bracket.
at this point I turned my key to on position to get the pump to run a few seconds and clear out the line of any junk from tank to filter(with drip pan still in place obviously) I did this about five times till nothing came out, but what did come out and into the pan was watery and smelled like varnish. The line from the filter to the motor also backdrained a little bit which I was happy to see.(clearing out any junk on post filter side of line)

this will be a good test for you too, if you get fuel spray from the tank/pump to the filter, then obviously the pumps working(you may have a clogged line from tank to filter, or filter to throttle body, especially if the cars been sitting a long time that ethanol is a killer, turns into white gunk and clogs everything.) you could even go as far as spraying some carb cleaner in the lines and using air compressor to blow through the lines to help clear out gunk/deposits, low pressure of course and let the crap drain back out of lines before reconnecting.

now put new filter with pre installed bracket back in, connecting both lines snug. Reinstall the bracket to body bolt(s) and the line holders. Then when all set in place give a once over on the inlet and outlet lines for a final tighten.
once done turn the key to on a few times(not cranking) to prime the air out of the line.
Then crank her over and see what happens. I’m total it took me about 40 mins to do this, which included jacking up the rear end for a little more space to see what I’m doing, as well as like fifteen trips in and out of the garage for different wrenches and more rags. I got a k+n filter from oriellys auto part for like 20 something bucks I believe. After that and new spark plugs and a fresh tank of high octane gas, the difference was night and day on how the engine ran.
good luck ,

btw, where are you located?

 

I just re-read your last post and you mention you have the fuel line feed disconnected at the motor. Definitely take off your fuel filter and spray carb cleaner in the line at the motor, and blow compressed air through it to make sure there is no blockage. If it blows through no problem spray more cleaner in there and follow the line down the body back to the filter to check if you have a rotted out line or a hole somewhere(you could also block one end and blow air into the line. If there are any holes in the line you will find it by sound or see a wet spot)

 

Small update this weekend:

I managed to hook up a 12V LED to the pump connector from the vehicle's harness such that I could watch it as I turned the ignition on and it did indeed light for a second or two so the pump is being told to prime the fuel rail its just not doing it.

Despite more fuel the pump is still not pumping anything even though I can hear it whirring away happily when supplied with 12V.

The weather here has been awful today so I didn't fancy crawling round on the wet floor trying to find fuel lines under the car, does anyone know where the fuel line runs from the tank to the engine and if there is a break in the line anywhere (i.e. a filter) that I could disconnect to see if the fuel is being pumped as far as that?

I need to know its the pump for sure at fault before I get charged £700 to change it only to find that when I go to an MOT the things fails catastrophically on rust and gets written off (worst case scenario here).

I am trying to get the car running so it can fail an MOT and I can figure out just what I am up against here :-/

Kind regards
FR

 

Through the magic of the internet I have found a filter should be in front of N/S rear wheel. My plan is now to break the line there and run the pump to see if fuel pours out - and of course replace the filter while I am at it.

If I get fuel there under pressure then I have a blockage further down the stream, If I don't get fuel there it will be a blockage in the tank/line out of or a dodgy pump - a garage job at any rate :-(

 

Hey go back in this thread to post 11 I think it was I gave you step by step info on the fuel filter change.

 

I think Psntbroke gave a summary of how to change the fuel pump in situ. See if you can find that post. It wasn't a walk in the park but he made it sound doable.

Sounds like you need the workshop manual as well which you can download from the stickies.

 

I have an XKR, so some things may be different.
My XKR was running fine, then it just shut off and wouldn't restart.
It would crank fine, but never catch and showed 0psi at the fuel schrader port/check valve in the engine bay.
I read the schematics here, found the fuel pump relays in the boot, and jumpered them individually to supply 12v to the in-tank pumps without having to get into the tank.
I could hear both run, but still had 0psi at the check port in the engine bay.
I put in a new fuel filter, but no change.
I drained the fuel tank, opened it up, and found that one of the fuel pump exit lines had come off.
Once that was fixed, it ran fine again.

 

Indeed you did Stevis05; my apologies I had forgotten about that and thank you

 

you don’t say what year of XKR you have, but as mentioned “both” pumps I’m guessing it’s a 4.0 liter 2002 or older, since the newer 4.2’s only have the one fuel pump.

in which case, your car should still have ran with only one pump operational. You
might be running on the auxiliary pump which normally only is activated during heavy acceleration. You can test if both pumps are working correctly by pulling the fuse for the primary pump. After the engine cranks for a while without starting, just a few seconds, the secondary pump should activate. You can reverse the procedure by pulling the secondary pump fuse to verify the primary pump is working as well.

Z

PS: hearing both pumps run is indeed a good sign, but having the car actually start and run on each pump separately is the best way to check if the output pressure is correct.

 

Yes, in a closed system.

In my case, both pumps were operational, but one pump had its exit fuel line come off the top fuel pump nipple, making it an open system

I assume that in this case (since it's been a long time since I was in there), the intact pump/hose simply vented all its flow back into the fuel tank through that open fuel line and no fuel pressure made it up to the engine for ignition.

Yes, it's a 2001 4.0.