Hi all,

Been trying to help a friend diagnose & repair a problem with his 1995 X300 3.2.

It all started the other evening - we went for a drive to drop another friend home, and the car was running beautifully. However when we reached my house, the car started idling very erratically, and then cut out. The fuel light had come on about a minute before, so we went and bought 5 litres of fuel and added it to the tank - the engine would now start briefly (ie 1 second or so) then die.

We left it, as it was late in the evening, and the next morning I went out to have another look - it started first time! I assumed it must have been damp or something, and drove the car back to my friend's workplace. However by the time I arrived (15 minutes approx), the car was idling badly again, and stalled in the car park. It would not re-start.

After this second run, the car refused to start at all (didn't seem to be firing). We checked each pen coil, and each one was giving a spark of very similar intensity, so this seemed ok. There is definitely some fuel reaching the engine, as we could smell it when we cranked the engine over before we removed the fuel pump fuse.

I found that if I hold the accelerator pedal in one particular place, the car would ALMOST start, but never quite managed to get going properly.

An OBD code reader returned P0116 and P0413, so our first port of call was to replace the 2 pin coolant temperature sensor (no difference), fit a new crimp onto the single pin coolant sensor (wire was very corroded) and also carried out a compression test (all cylinders read more or less the same). We have also changed the fuel filter and cleaned the idle control valve as it was very coked up.

It was recommended that we try the flood clear procedure (crank engine with throttle full open, then slowly back it off), and since then, the engine now fires, but won't keep running for more than a second or so.

One thing I have noticed is that the car is much more likely to try and start if I turn the ignition on then off a few times before I try to start the engine (e.g. if I prime it a lot). Also, when trying to start the car, there is a lot of gurgling coming from the fuel tank (we have taken the liner out that covers the tank). Wondering if this could be a fuel pressure / delivery problem now?

Any ideas welcomed!

Thanks

Rob

 

When you crank what does the rev counter register?

 

Around 2-300 RPM I seem to recall from last night

Thanks,

Rob

 

A fuel pressure test is the only real way I reckon, as it sounds like a dying pump, "better results if I prime it a few times".

They do NOT like to run too often or long in the fuel light area. If the car has done somewhere around 100k miles (160k kms) the pump is on borrowed time, ACCORDING to the manufacturers, NOT me.

Mine has done 16500okms and sometimes you can hear the pump, and when you can hear the pump the engine is a little "off", so pump replacement is very close.

My XJ-S pump died at 145k kms, and again at 249k kms, so maybe they are right, dunno.

 

Just remebered something I read somewhere recently, forgot where, I do that often.

There was a bulletin about the fuel hose becoming dislodged from the pump spigot inside the tank, and the bulletin was to fit a clamp to said hose, now I think it was X300, but it may have been "late XJ40", as I said I do forget. However it also stated that the replacement pumps have a flare arrangement on this spigot to prevent hose dislodgement. Interesting at least.

 

Check the fuel line where it goes into the fuel injectors. Disconnect the line right where it goes into the fuel injectors. Once that’s done have someone get in the drivers seat and turn the key to start it. Tell the person that’s turning the key to do it in short spurts the reason for the short spurts if the fuel pump is working at full pressure fuel won’t be all over you and your engine. If gas comes out at a good pressure rate you need to check for spark from the plugs. If NO gas comes out check the fuel relay if the relay has burned prongs, change the relay. The next move is to check the fuel filter if that’s okay now it's time to go directly to the fuel pump. I hope this helps.

 

Thanks for the replies guys, our next job on the list is certainly a fuel pressure test, just as soon as I can find someone local who has one for loan or hire (seems silly to spend out £80 on a tester when it might not be the problem!).

We know we are getting sparks on all the coil packs, so it seems a most likely to be a fuel issue.

The car has done 157,000 miles, I don't know if the pump has ever been replaced, but if not then I guess it's fairly likely to be our problem!

As soon as we've done the next test i'll post an update to let you know how we've got on!

Cheers,

Rob

 

Ok, how's this for an odd update?

Since we have added another 10 litres of fuel, we have found that if we let the car sit for a while (say 24 hours), then try to start it, the car will fire, and run absolutely fine for about 3 or 4 minutes. After this time, the idle becomes rough, then the engine will stall and won't restart.

We disconnected the fuel supply line from the fuel rail, to check that the pump was priming and running correctly - seems to be ok, but I did notice that the collected fuel really didn't have much of a smell to it...

Does this sound like fuel contamination? I'm wondering if leaving the car for so long between starts is allowing the fuel to settle/separate from whatever the contaminant is, which allows it to start, then the return pressure is stirring everything in the tank up and causing the contamination to enter the fuel system again?

Ideas appreciated as always!

Thanks

Rob

 

Nah, fuel remains volatile enough to run an engine for about 3+months. NOT sure about this Ethanol stuff, may be different.

If it dont smell like petrol it probably aint petrol????, but what is it?????.

Secondly that 3-4 minutes could be a fuel tank vent issue, iffy I know, but worth trying with the filler cap OFF, and see if anything changes.

When it finally stalls, crack that fuel connection at the fuel rail, and see if you get a fuel "squirt" or a "dribble". If it is a "squirt" you still got reasonable pressure, if its a "dribble" you have lost pressure, pump has died, they do that.

Since you will have fuel spillage,

TAKE ALL THE REQUIRED CARE BBQ JAGUAR TASTES AWFUL, I MEAN IT.

Another thing to try, is find someone with GOOD hearing, place them in the boot, dont shut them in its not nice, start (or try to start) the engine, and they should hear the fuel pump inside the tank "whirring", if it starts and stops "whirring" sounds like a pump issue, check the pump relay (in the boot fuse box I think), as some people have had them burn the contacts and the pump stops.

You state that the idle gets all offish, is it overfueling????, could be the fuel pressure regulator has failed, and flooding the engine, I have had that with the V12's, and these are the same basic unit, anything is possible. Remove that small vac hose to the regulator and see if it has fuel dribbling out of it, or smells of fuel, which would indicate a fractured diaphragm, problem found.

 

Just a rule here guys most fuel pumps on cars should supply 1 pint of fuel every 30 seconds. To test it take out the fuel relay and jump out the circuit. You then need to find the Shriver valve, hopefully you have one on the fuel rail. I then use an old freon charging line that will depress the shriver valve, put the other end into a 20 oz cokacola bottle. Get someone to turn the key to the run position the fuel pump shoud now start and run without stopping time on 30 seconds then the key off. The bottle should be approx 3/4 full if it's less than that then the pump in on its way out..

 

Ok, so having been out in the cold for the last couple of hours, we may have some progress!

We have managed to get the car running, and had it going for about 15-20 minutes without major issue to begin with. However, after revving the engine to around 4000 rpm then backing off the throttle, the car idled at 1500 rpm instead of the usual 800. I found that if I then "blipped" the throttle, the idle revs would happily drop back to 800 rpm, but the idle was not completely smooth.

We tried to move it, but after moving it forward it stalled.

Does this behavior sound like a faulty throttle position sensor??

Thanks

Rob

 

Maybe.

I just re-read yor original post, just to be sure.

I reckon it MAY be a cruddy throttle body and disc. Give it a GOOD clean, NOT easy, removal is the only proper way, but if you remove the intake trunk and soak a clean rag with solvent (carby cleaner) and wipe all the black gunk you see out of the body and off the disc. It may take a few goes to get it all clean, so dont rush it. Mine required carefull scraping to remove it when I first purchased the car, so be warned.I am used to this gunk, the V12's are habitual "gunkers".

This will restore the air bleed gap designed into it, and MAY sort your issues.

The TPS is a pain to get at, and fills up with all the oily gunk from that throttle shaft, and that is NOT good for the TPS, and they can/do fail from that contamination. Again, I gave mine a good flushing with solvent back then and have no issues, or codes.

 

Thanks for the advice, will whip it off over the weekend, give it a good clean and let you know how we get on!

Cheers again,

Rob

 

Hi all,

Still not got to the bottom of this, been trying a few different things though so I thought I would post an update to see if it sparks any flashes of wisdom from any of you!

Since the last time, we have removed and thoroughly cleaned the throttle body - a bit surprised to find about 1/2" of oily gunk throughout it when first removed! We also replaced a plug coil which had a split insulator in case that was causing the problem. At this point the car still would not start.

We thought that we had a breakthrough after my friend took a trip to the local breakers yard, where he picked up a second hand idle control valve (as we suspected that the original was faulty), and fitted it. At this point, the car started, so we let it sit and idle for 20-30 minutes, then ran it (hard) around his work car park where it has been parked since it was recovered by the RAC! All seemed well, and cleaning the throttle out had given the car a new lease of life (I almost lost the back end in the car park, and it never had that power before!!), so we took a trip over to Lakeside in Essex.

All was well, until we pulled into the car park, when the car began to idle roughly, then stalled as we pulled into the parking space. As of this moment in time, that was the last time that the car ran under its own steam. It would not restart, so we called the RAC, the patrol came round, and admitted to being a bit stumped, so he called his senior, who also came to investigate. After adding 10 quid of petrol, and about 40 minutes of trying different things, they gave up and called a recovery truck. The senior guy said it seemed like a fuelling problem, but he wasn't sure.

The car is now sitting outside, and it still won't start. Tonight we tried swapping the fuel pump relay with another identical one in the fuse box, but to be honest it seemed to be working fine anyway (ignition on - click from relay and whine from fuel pump - after one or 2 seconds another click and the whining would stop as the system was primed).

After that, we tried removing the idle control valve again, and starting the engine without it in place - the engine started successfully, and revved high for about 10 seconds before it made a "pop" noise (like a backfire) and stalled.

It seems to me like we have an air - fuel ratio issue - i'm starting to wonder if it could be the MAF as previously suggested.

Anyone got any ideas where to turn next?

Thanks

Rob

P.S. Sorry for the essay!!!

 

Ok, so another frustrating evening!

Start point - car would fire then immediately die, as if it was burning the "prime" of fuel, but not getting any more.

We connected the fuel pressure tester into the supply line to the fuel rail. Turned the key to position 2, which primed up to around 45psi on the tester.

Released the pressure, and cranked the engine, which also jumped to around 45psi... repeated 5 or 6 times with the same results, so now assuming that the fuel supply is good.

We metered the throttle position sensor, which returned similar readings to those on Jim Butterworth's site, so assumed this was ok too.

At this point, I unplugged the MAF and cranked the engine - it started, but with a very rough idle. I plugged the MAF back in, but it seemed to make no difference. Also, if I tried to rev the car, it would try to stall. After 5-10 minutes, I switched off the engine, and then it would not restart.

We also picked up a complete second hand throttle body today from a local breakers yard, so having tested the throttle position sensor on the new body, we swapped the whole assembly.

Now we're still pretty much back where we started, the car tries to start on the key but won't run.

HELP!!!!!!

Thanks

Rob

 

Gut feeling here.

MAF maybe, although I have had NO issues with any of the cars I have had, Jag and others with the MAF, but it seems to be a favourite subject on the forums.

Crank angle sensor. I say this cause mine died, bugga, drove in the driveway, spouse wanted to go out for tea, X300 NO GO, bugga again, took the trusty XJ-S (her car) and heard all about how reliable hers is compared to mine, hahaha..

Tried all manner of "sensible" things, no go. Stole a sensor from the nieghbours car (he was at work, car home) , and succcess, life restored. Purchased a new CAS all sweet, so is the neighbours.

NO sense at the same time, still got the old sensor, so just for the hell of it, refitted it and NO GO. Again I am hearing 100k miles and these things die, WHY, no moving parts, no contacting parts, makes no sense to me.

 

Cheers Grant,

Going to do some more testing over the next day or two, will add your suggestions to the list and let you know how we get one!

Thanks

Rob

 

Hi all,

Still not any further on really... it's all getting a bit
depressing now!

We've checked the ECU connectors (no security bar so no
problem there) and they are both completely clean and free
of any signs of ingress.

We've also checked the white and black connectors behind the
right side headlight, and they appear to be fine.

Fitted a new battery today as the old one had completely
given up the ghost from repeated cranking/charging/jump
starting. Car now cranks much more quickly but still fires
and almost immediately dies.

We removed the crank sensor, and metered it on mV while
passing a lump of steel back and forth in front of it, but
there didn't seem to be much at all happening (0.1-1mV)
unless we had the metal practically touching the sensor
(less than 1mm) whereas in the car there seems to be around
a 4-5mm operating gap. However, i'm not sure if this is an
issue as the tacho is reading at around 200 RPM while
cranking. It has the expected 1300 ohm resistance.

If I unplug either the crank or cam sensors the car doesn't
seem to fire at all.

On top of all that, it appears someone has noticed the car
has been sat for some time and has tried to get into it by
breaking the rear quarter light and bending the chrome
surround! Not impressed, especially as this is a nice quiet
road where everyone knows each other!

Any ideas where to go next on the non start issue
appreciated.

Thanks

Rob

 

How closely have you checked all of the coils? What is their origin? How old are they? They may generate a discharge but are you sure it is enough and on time?

Check carefully for cracks and for bubbles under the sealant on the cover.

Also it is best to use a conductive grease between the tip of the coil and the top of the plug.

You did say you found cracks in some of the boots. Look for small cracks in the bakelite. A quick fix that is a good test is to wind the entire coil in resistant silicone tape. Cover each one completely and then plug them up and test fire. They are amazingly sensitive to heat and the ECU is just as sensitive to improper fluctuations in charge and your coils are discharging into the cover or back into the ignition system, you can have a world of problems.

Just some ideas.

Because basically, if it's got spark, fuel and timing, it should be running.

 

Update - replaced MAF and the car now starts first time. However, it now idles between 100 and 1300 RPM, never any lower. Any ideas what may cause this?

Thanks

Rob