I am going thru and checking everything you guys have recommended. Also, what should the valve clearance be? I am seeing conflicting numbers on other posts.

John

 

Update: Compression was 120 to 130 psi on all 6 cylinders. Getting strong spark and tested each plug when grounded to exhaust manifold. Injectors are spraying and plugs are wet, after cranking and trying to start. My guess is that the spark is happening but at the wrong time. I had set the distributor when I had the number one cylinder at tdc, and was setting the cam shafts with the jag cam tool, so I am on the compression stroke. i have tried rotating the distributor housing and cap slightly, thinking that I may have to advance or retard the spark from the rotor to the cap. When I unplug the Maf, I get a Maf error code, so I think the Maf is ok. battery voltage is good and getting strong crank. Any Ideas??????
John

 

Hi John,

As suggested, show us a pic of the leads on the distributor csp and which cylinders they go to.

Also have you changed the fuel for guaranteed fresh fuel?

Is the butterfly devinitely able to open? Have you tried disconnecting the air filter from the MAF

Paul

 

Thanks Paul,
yes I have distributor wires positioned correctly. there is even a jaguar label on the air filter canister with the firing order. Fuel is fresh, less than one month and I have air filter canister removed from the Maf I have a spare ECM and will try that tomorrow
John

 

But here then is also question I have. So when the rotor is pointing at the plug wire for #1 at tdc, that means both exhaust and inlet valves are closed. So does the spark and fuel injection occur at exactly tdc, or slightly before or after tdc? Many engines will have a 10 degree adjustment for this, which of course is done on the timing marks. So does the ecm make this adjustment? or should I manually rotate the distributor housing slightly?
John

 

Logically thinking, the spark and fuel injection should occur, as the inlet valves are opening after being closed at Tdc. Is this assumption correct? Does the Ecm control this adjustment between the CPS and the rotor?
John

 

The fuel injection goes with the inlet valves. Air and fuel go into the cylinder together on the down intake stroke. The piston then goes up on the compression stroke, with all valves closed. Ignition is at the top of the compression stroke, maybe 10 degrees before the top of the stroke, but on the compression stroke. Either way, intake valves opening to ignition are a full revolution out from each other.

 

Dear G,
Exactly, just as I thought and you point out, ignition must happen slightly before TDC, 10 degrees is used on many engines. So when I set the distributor, do I have the rotor pointing and centered on a plug wire stud in the cap or slightly ahead of the stud?
John

 

The timing of the spark is controlled by the ignition system, NOT by the rotor position (on some cars turning the distributor changes the spark timing because it changes the position of the spark timing mechanism at the base of the unit - not because it changes the rotor position relative to the cap HT posts). On your vehicle, I do not think you have the distributor controlling the spark timing, you have a crank sensor which does that. You can verify spark timing against the crank position with a strobe light, or no doubt with a Jaguar compatible computer gizmo.

 

Thanks Greg,
Had the distributor removed today, in order to remove the upper timing chain tensioner, and set the cams with #1 at tdc. With the #1 still at tdc and the cams set properly, I installed the distributor. So if i am correct, the rotor is now pointing at the #1 plug post on the distributor cap and I can set the firing order from there.
John

 

John,

I assume that with all the head work and cam timing etc that you're working from the Jaguar workshop Manual. In which case, I guess you will know the rotor position routine. So forgive me if I'm covering stuff you know, but I thought I'd just paste the page with the positioning detail in case you hadn't seen it in the manual.

Cheers

Paul

 

Thank You So Much Paul,
No I had not seen those pages, it will be a great help.
John

 

John,

Let me know if you need any more pages out of the manual on any aspect of the ignition, fuelling, timing etc etc

Paul

 

Paul Thank you for the offer,
Which workshop manual are you using, the akm9063 book? The manuals I have are no where near as detailed.
John

 

Paul,
Could you do another post of the second page you sent on the distributor. Figure 3 on the second page, got cut off and that figure shows the starting point for the rotor.
John

 

Paul,
I think figure 3 will show the rotor pointing to 6 o'clock and the distributor cap notch at 5 o'clock. if I am correct don't bother sending photo.
John

 

John,

I'll be home in an hour and will post it anyway just to be sure.

Cheers

Paul

 

John,

Here you go.

I have a number of manuals for the XJS. This particular page is from Vol 2 of the XJS facelift service manual Publication Part No, JJM 10 04 06 / 20

There's a number of pages in there, as you would expect on exactly how the ignition systems and fuelling systems work. As I said if you do need any further info, just shout.

As always, I'd really suggest you get hold of the appropriate manuals. It's the first thing I do on any vehicle that I own. In the UK, we grew up on the "Haynes" manuals that were published for many cars. As I got older, I realised that it was madness to try and run a car without the detailed manufacturers manuals. Whilst the internet and forums such as this have helped all owners, I still insist on having detailed manuals for all my vehicles.

Hope the pic is ok. As I said, just shout if you need more.

Cheers

Paul

 

Thanks Paul,
Yes I have jaguar official diagnostic and repair manuals, as well as some other online manuals, but none went into any detailed instruction on distributor setting. So today I went back to the basics of checking fuel and tomorrow will check spark again. Pulled the fuel rail with injectors attached, cranked and got fuel spray from all 6, so that rules out any sensor that would cut off the fuel pump. Double checked all fuses and relays especially the (Orangeblossom) relay under the right side knee bolster. Changed coolant temperature sensor and temp sending plug. Inertia switch is operating properly. Switched out ECM's (I have two) no change, just crank and no start, even with a spray of starting fluid. Switched out MAF's (I have two) no change. So tomorrow I will do like Nigel on Fawlty Towers and give the car a good thrashing with a tree branch.
Is there possibly some sensor that would have the ECM shut down fuel or spark?
John

 

I am thinking to try another CPS, would that be a logical next step. As previously mentioned the CPS air gap is 0.030
John