The good thing about cleaning the throttle body/plate & part-load breather is that it doesn't cost much-if anything.

Also, they were both known issues with the early X308's & Jaguar issued Technical Service Bulletins about the engine stalling issues. If the engine can't suck any air in because the breather & throttle assemblies are all coked up, then it doesn't matter how much electrical/fuel system fault finding you do.

If the engine physically can't suck in any air due to carbon blockages or jammed throttles, then it ain't going to start...

 

The fuel pump has 2 stages one when the key is turned on then the ECM takes control of the pump resulting in 2 sources of power to the pump. See the attached link.

Link JagRepair.com - Jaguar Repair Information Resource

 

I'll be going through this tomorrow... looks to be the most likely issue.

 

About to throw in the towel on this car. Gone through every test, and everything is as it should be.

The last possibility now is the cam timing. So sad because the car is in wonderful low miles condition. And I simply can't stand to even look at it anymore.

$3500 or nearest offer takes it.

 

Does the pump come on and produce fuel pressure of around 40PSI?

Note: I do not see you as one to give up.

 

Yep. The car gets spark and fuel pressure but no injector pulses. It doesn't even get small pops from spraying ether as if the car might try to start. The pump primes and holds pressure, it actually goes up to 43-45 on this gauge... and still not even a hint of starting.

I tend not to give up, but with winter coming and the car being outside it leaves me the weekends to mess with it. This car has already annoyed me sufficiently to not want it anymore. If it begins to take away my weekends or costs me a delay in my 1964 Lincoln's restoration, that annoyance will become resentment.

 

Time to walk away and give it a rest. If you elect to use it as target practice let me know. Did you see the PM I sent to you?

 

I can't remember if you have checked for water in the fuel yet- just bleed a little fuel into a glas container using the hose from a fuel pressure tester. And... You have tested the compression, right?

 

Highlander, don't give up yet! Gus put a bug in my ear about this yesterday, and in between copious amounts of turkey and dressing etc. over the day, I pondered a bit.
I'm wondering if the car has possibly set a fault that your reader cannot see. Something that can be maddening can happen and leave a guy in the predicament you seem to have.

First things first. Considering everything both you and the car have been through, I would suggest backing up a bit and reassessing. Start by making sure you have dry cylinders and spark plugs, then do a few things in this order.

1. Be sure you have the original ECM installed, the substitution you have done may have complicated the issue. You have a 1998 with PATS security that reads the key pellet. The ECM is involved with that system and substitution won't get you anywhere unless you have the Jaguar diagnostic equipment to sync it up. Without that it will never initiate fuel injection.

2. Disconnect the battery for a few minutes, reconnect and let all the systems re-initialize properly.

3. With the car doors etc. all closed, lock the car with the key to be sure the security system locks and arms correctly with the one chirp. Wait a minute and make sure nothing out of the ordinary occurs, then unlock the car and disarm the security system. If all that seems OK, we are confident the security system is not interrupting fuel injection for any reason.

4. Enter the car and key to ignition on ONLY. Look at the shifter and see if the "P" for park is illuminated. If it is not, that might be pay dirt. If it is lit, that at least tells us the shifter is probably OK.

5. Press the brake pedal and see if the shifter will move from park, if it does, march through all the gear positions and check the alignment of the cable detents to the physical notches in the shift gate. If the detents don't match up really close, that tells us something. If they do seem to align OK, flip the shifter back up to Park sort of forcefully.

6. Press the accelerator pedal to about 3/4 travel and give it a crank and hold it for up to 20 seconds.

Let us know the results and what if any action you got from the engine in the way of sounding like it's attempting to fire.

What I'm wondering about is the possibility of a failure in the trans rotary switch. There is a failure mode where it doesn't "agree" with the switching in the shifter, and the result is a car that cranks, but the ECM never initiates fueling or sometimes ignition. This failure can set faults P1516 or P1517, which are corporate codes and many times not recognized by generic scan tools. Once in a while a P0706 will set, but not always. My understanding is that this business is another safeguard against a car starting when not in park or neutral. It protects against a shifter being in Park, which would allow starting, and a trans actually being in gear during a start. It's just another thing that they can do with a multiplexed car, without adding more "stuff" to do it.

Certainly worth a try.

Good luck!

 

Just a thought, I recently had to swap out a ECM (my car would not start) I picked up one on ebay, every single number matched.
The jag dealer said it was from a manual(stick shift) car and therefore displayed ABS/Stab codes.

Thats what I got told, I used a second ECM (same numbers again) all worked fine.
So manual and Auto ecms might be different although they have same numbers??? who knows????

Now if I could only stop my passive alarm from doing its own thing......
Stan

 

Law of unintended consequences.

No water in fuel. Plenty of fuel pressure. Plenty of compression (tested that after oiling the cylinders just in case of a cylinder wash situation I feared, but the car still had compression the whole time anyway.

Running fuel from the schrader to a bottle showed that while there was plenty of pressure building at key on, flow rate drops almost immediately. The pump runs fine, but isn't pushing much at the rail.

Plenty of fuel flowing to the filter, clean and dry. Pump output is perhaps more than I had expected (whoops... it'll evaporate). New filter. Old filter was original to the car. Car is now popping and trying to run on short squirts of starting fluid and whatever gas is reaching the fuel rails.

Now I've got to check the typically unlikely but increasingly likely in this instance possibility of a line blockage. Are there any soft lines to look for that may be collapsing (or being ethanol-degraded) internally? Any that are perhaps a common trouble spot, or relatively common, or at least been seen before? I'll be very annoyed and very relieved if it all boils down to something so stupid and simple.

 

This is very encouraging indeed.

If you go back to the original troubleshooting now, perhaps it will be resolved?

(clean spark plugs, compression test/oil unplug battery)

 

That is not really indicative of anything as the rail will quickly depressurise once open. If you suspect that the fuel pump is not keeping up then you need to put the fuel pressure gauge on and observe while you are starting/running

There is a short in-tank hose from the pump to the outlet line. There is also a in-tank filter sock on the pump inlet.

 

There are not two sources of power to the fuel pump. There is one wire coming from the ECM which grounds one pole of the relay coil. Grounding the relay coil results in power flowing across the relay power poles via a single wire leading to the fuel pump.

The ECM toggles power as required. From key on, the ECM will energise the relay for a short period of time to prime the fuel rail. It then cuts power. Once the engine is turning, the relay is energised again and remains energised except for conditions such as a impact or rollover.

There are small differences seen in the supercharged cars due to the presence of redundant pumps.

 

Thinking (perhaps incorrectly) about the well that supplies my house and how the jet pump has no issue with building pressure but cannot maintain volume when the filters get beyond a certain point, it would seem a reasonable assumption that if volume is compromised then no matter how tip-top the fuel pump is (and with the filter out, it filled a gallon bucket faster than anticipated) if it can't push enough fuel past a blockage, the car will never get running properly.

When cranking, the pressure at the gauge on the rail goes up to 43-45. it drops, then spikes, then drops, then spikes. The pump runs solidly when jumpered, operates properly when the relay is in place, but it took almost 3 minutes to get 16 oz from the schrader. That's 9.5 liters per hour, roughly. Hardly seems enough to run an injector system... actually, around 10% of what I'd expect.

Am I off-base in my thinking?

 

As an addendum, I'd like to sincerely thank everyone who has contributed in this thread. All ideas are well-received, well-considered, and have been pursued - and there finally seems to be some type of light at the end of this tunnel. Hopefully not a cat in flames.

 

I have had the fuel pump inlet sock that Plums referred to get blocked, then apparently drop the silt back into the tank, then pick it up again, causing the fuel presure spikes you refer to. It was all I changed, and everything went back to normal.

 

Progress, of sorts. Running but just barely. P1336 now - CMP/CKP sync issues.

Video at Index of /jag

 

Just checking- did you disconnect and reconnect battery? Also, when it first fires up you should let it go through the gyrations for a couple minutes.

 

Repeatedly, as mentioned in the thread. Just did it again now and am back to strong cranking with no popping or start/rough running. This was a step backward.


The videos posted directly before your post show the car "going through the gyrations" for almost 20 minutes - long enough to get up to full running temp according to the gauge - but it never smoothed out.