1999 XJR 4.0SC

So the 1st mistake I clearly made was blending 2 unrelated problems rather than fixing one and then attacking the other after verifying the fix for the 1st. So long story...….1st was an apparent power steering pump failure while out driving aggressively (wet weather donuts). Pulled the car in the garage and the belt was not broken, neither was any hoses and fluid was good so I assumed either rack or pump failure. chose the easier of the 2 and replaced the pump which was super easy but once done It wouldn't start. I was able to get the car to start by spraying fuel into the throttle so I knew I had a fuel problem. The prior couple months I had been getting signs of a bad fuel pump/clogged filter or injector issue prior to the power steering failure. The car would start fine when cold but when warm it would need 3xs the amount of cranking time to start. Also it would briefly lose power for a second or 2 wile cruising as if fuel supply stopped briefly and then returned, full throttle seemed fine. So when this no start came up I said time to replace the fuel pumps. Got to them and the strainers were so clogged it was unbelievable they were working. The rubber hoses were cracked and brittle. I replaced both pumps, hoses and relays for good measure. Instead of verifying I now had a running vehicle I immediately went to the secondary tensioners I had been putting off for a while. There was a timing chain rattle at cold startup which indicated these needed to be done. I completed this job using the Zip Tie method to lock the chain to the exhaust sprocket. The process went well with no issues expect that the passenger side had a lot of valve spring tension on it when I pulled it. Once I had gotten all the caps off the cam was wedged in and wouldn't come out. I solved this by reinstalling and torquing the caps and then taking them off again more slowly. It worked better but the cam was still wedged a bit and a little tug got it out whereas the driver side lifted out easily. Anyway I continued the job, installed the new tensioner, caps and cam covers on each side. I took care to make sure there were no scratches or damaged components before reassembly. When I went to crank It did not start.

At this point I thought I should verify my fuel pump fix was A-OK. Got a pressure gauge and I saw 45psi at the rail test port. The pressure did not hold like it should and slowly bled down so I may still have a leaky injector or bad regulator allowing pressure to return to the tank. My thought process is though this is an issue that needs fixing the car should atleast start for a moment with that primed fuel supply and then die. Just for good measure I got a spark tester and tested one plug on each bank and it had a spark pulse. This led me to think maybe I did something wrong while replacing the tensioners so I pulled both cam covers. All four cam flats nearest the tensioner align which from what I understand is how it should be. I am now at a loss and don't really know where to go from here. I guess one of my questions is could there have been anything else I screwed up with the tensioners to cause the no start? From my perspective I don't think so. I'm thinking though my fuel pumps and filter (changed that also) were heavily clogged maybe the initial no start wasn't caused by their condition. Here are my thoughts:

1) power steering pump replacement surely is not related to current issues
2) Engine cranks over fine and I don't see how there could be any other issues cause by the tensioner replacement.
3) Seems I still have a fuel problem

I swapped out the fuel injector relay with a known good relay, no change. I need a simple way of checking if the injectors are firing without a noid light or expensive test equipment. I think the injectors may be firing though because I pulled all the plugs, cleaned and gapped them and they seemed to be fuel fouled. Squirted a bit of oil in each cylinder to ensure good compression and I got a brief start with fuel sprayed into the throttle but still no start on its own. Any ideas will help. Thanks all.

 

I see a lot of folks stopped by but had no suggestions. Lets see if I can help you out.I assume from your write up that you used the tie wrap method for the change out. I must ask did you tie wrap the chain to both the intake and exhaust sprockets?.
The first step for troubleshooting this is you need to do a compression test.We need to know that we have good compression.
The next thing maybe even before the compression test is to do a very thorough examination of the work area and see if by chance you have leaned on or pushed against any thing that has become dislodged.
I wouldn't not recommend any further use of starting fluid. It may start the engine but it is highly volatile and can ruin the intake manifold and damage the 02 sensors.
Let me know what compression readings are and I will in the mean time look at injector testing.

 

Thanks for the reply. While doing the tensioners I tied only the exhaust sprocket to the chain. Theres tons of write ups and videos out there but i didnt notice anyone tying both. Does seem like a good idea in hindsight to ensure no movement. I like your thought process regarding compression. A good compression test should indicate the valvetrain is still properly timed. I will look to do that next. Regarding the injectors i saw a video where a guy simply pulled the connector with key on engine off and tested for power using a test light connected to ground. Once he verified it had the power from the fuel injector relay he then plugged it in and back probed the opposite wire while cranking. With the test light connected to 12v instead this time. What he saw was a pulse in the test light which represented injector pulse as the ecm switched ground on and off. Could this work on my XJR.? I was fearful maybe it could damage the ecm.

 

Vern, is there a possibility of bore wash this late in the age game? Not saying it is wwilson0704, but here's a link to review.... JagRepair.com - Jaguar Repair Information Resource

May I suggest a simple test after the compression test is determined, perhaps the MAF went T up (the 3x starting time and power loss)? Disconnect the MAF and try starting it....the ECU will go into a default and provide the ability for the car to run if the MAF is the issue and allow fuel trims to level out. Its a code you can clear after. Also, did you clean your tank? I'm wondering how the residue got into it, I did my pumps a few years ago and it was spotless in there.

 

Good morning Highhorse, My first thought to was bore wash. The poster stated he had put oil in the cylinders when he found the plugs coated in fuel, so I don't think it is bore wash but then again it might be.
I think he should try the bore wash procedure first and then move on to the compression test. I would do a first compression test and then add oil to the cylinders and repeat the test to see if it improves.
Unfortunately with not being on site it hard to determine what the exact cause is but the various tests will give us some insight in to helping him resolve the issue.

 

This is getting complicated: still, I have to believe there is something he did that caused the non-starting problem.

Bore wash, maybe, but should have been fixed by the addition of oil to a cylinder to two. But his plugs were wet. Suggests a problem with ignition, I think. Maybe a critical wire torn, grounded, cut -- mostly in the circuits to the coil packs. Maybe corroded coils?

Maybe a review of all steps, again.

And then, since you were working on the power steering pump, check that there is electricity at each fuse in the fuse box on the left side of the engine bay. Corrosion in this box has caused cases of strange behavior.

 

Thanks all for the suggestions. So I did the compression test with somewhat disappointing but also reassuring results in a way. Fuel pump relays pulled, all coils and plugs removed I got the following in PSI: Drivers (left) side from front to back - 70, 75, 70, 75. Passenger side from front to back - 70, 70, 70, 75. I was definitely dismayed by such low numbers but the consistency was a good sign. So I dropped in 4ml of 10w-40 and repeated. Drivers side front to back - 105, 115, 110, 115. Passenger side front to back - 110, 110, 80, 85. This struck me as odd since it was so consistent the first time around. Since I squirted the oil in all cylinders and then began testing I figured maybe that extra seal created by the oil had worn off so I gave those last 2 cylinders another 2ml. After the additional oil I only saw 90 in both the last 2 cylinders. Throughout the entire test with and without oil I had been doing 5 hits per cylinder. So the last thing I did was allow 6 hits on those last 2 cylinders and they each developed 110.

So what I don't know for sure is what this engine should develop?? Its a 99 with 162,000 miles so it is surely beat up but ran great, made great power etc. Something that could be playing a role in the low #s is the fact that it has 0w-30 oil in it, a suggestion to help with the timing chain rattle which really didn't help. I intended to go to 10w-40 with a quart of lucas stabilizer after this work was completed.

2nd what is the interpretation of the results? I guess it depends on what normal spec is and how far away from it we are (that's where I rely on you guys). I was thinking 120 was a good # which means Im close to it. Likely have some pretty worn piston rings coupled with inadequate oil viscosity, But do you see anything that indicates a timing issue?

Regarding other suggestions - all fuses under the hood (both left and right side have been checked, relays that sit next to ecm checked. Tested for spark and it has spark. Rubber plug boots could use replacing but it ran when it came in the garage initially for the power steering pump. There are no codes and there were none prior to any of this. I regularly drove the car with my scan tool connected b/c I find it interesting to see exactly what the engine is doing and that was done days before pulling into the garage. The MAF was reading properly at that time and I have tried to start it without it connected with no success. The fuel pumps had what seemed like some kind of black insulating material attached to them. It had totally broken down and was like the consistency of chewed gum. It had virtually totally clogged the strainers on the pumps. I got it all out by hand, new pump, screens and filter installed. The stuff was thick so there was no way it could pass through the strainers and filter. At install the pumps were tested and created 70 psi with just 12 inch hose between the pump and the gauge. They held pressure at 60 psi for hours so they seem to be good.

Last note - when removing the plugs for the test a few of them were wet again and I had dried them all the last time they were out yesterday. Granted, I have done tons of attempts to start since then but they really shouldn't be wet like that from what I understand even after all that cranking w/ no start. I couldn't tell by smell if it was oil or fuel so I put my torch to it and it did not ignite leading me to think its oil. Seems I have some leaky valve seals to go with my piston rings maybe? I was thinking of confirming my injectors are firing and if they are, popping in new plugs and rubber boots and changing the oil and attempting to start her up again. What do you think?

 

Its probably obvious but I didn't literally state it so to be clear Im thinking of changing the oil to get that 0w-30 out and the thicker 10w-40 in to help the valves and rings do their jobs a bit better.

 

Ok it sounds like the results for the compression test are leaning toward bore wash. The good news is it doesn't appear to be a timing issue or the results would have been much worse.
First lets see if you can get here started. Put everything back together and let's get ready to fire it up.
Push the accelerator pedal all the way down to the floor and hold it there. Don't let up on the pedal during the sequence.
Crank the engine over for about 10 seconds and turn the key off 10 seconds. Repeat this at least 4 or 5 times. Then turn the key to crank for starting, as it is cranking slowly raise the pedal from the floor. Putting the pedal on the floor with the key off shuts off the injectors. Cranking without fuel will allow the cylinders to seal and finally as you are releasing the pedal fuel will be restored. You may have to repeat a couple of times but it should fire up and run.
Now for the 10w-30w oil. The handbook recommends 0w-30w or 5w-30w if you jack up to 10w-30w you run the risk of damage to the mains and rods with have very tight clearances and are not really designed for 10w-30w oil. The key to preventing bore wash is to DRIVE IT. Bore wash occurs when the vehicle sits for long periods of time and the oil film dries off of the cylinder walls.

 

Jaguar manuals state that 5W-30 is the initial fill and that it is also for maximum economy (0W-30 is not recommended). At the same time, the manuals state that 15W-40 is fine for ambient temperatures that do not fall below freezing (below 0C). So 10W-40 is perfect for your sunny Florida. In my 4.0 SC engine (Daimler Super V8, in Malaysia), I am using fully synthetic 4T (motorcycle) oil 10W-40 with addition of Liqui Moly MoS2. Why motorcycle oil - because nowadays only motorcycle oils still have sufficient levels of Zinc and Phosphorus (ZDDP) for good wear protection of flat tappet engines (like the AJ26/27). I add MoS2 as a friction modifier since motorcycle oils do not have as much of it as car engine oils; however, this is only for better economy and not really as anti-wear additive (although MoS2 helps there too).

With regard to your compression readings, they look fine to me. The proper method of compression measurement is to do it on a warm engine and with the throttle fully open. With fully open throttle, you will get higher compression readings.

I believe your no-start is caused by something else, maybe just coincidental with your work. It looks like the first no-start (after replacing the PS pump) was caused by clogged fuel pumps and filter. Since, after you replaced these, you still have no-start, I would remove the fuel pressure regulator, the fuel rails and the injectors and thoroughly inspect and clean them (backflush) as some of the debris from your deteriorated fuel pumps may have entered the fuel system and clogged the injector strainers.

 

Thank you avern1 and M. Stojanovic. You two are like the left and right side of 1 brain. 2 totally different next steps, but 2 totally logical and likely correct next steps. AWESOME! This is my first non American car so its great to have experts to go to at the drop of a dime. Bore wash does sound probable. With all of this work and the fact that I don't need to drive the car daily it has sat for maybe 3 months. I will try the bore wash procedure when I work on it tonight as a first step. If I get nothing we will go to the other side of the brain and go back into the fuel system. I will update afterwards.

 

I used 10W40 in my 97. High zink is for engines with rocker arms.

 

According to the information I have read, the higher Zinc/Phosphorus (ZDDP) additive content in engine oil is required for engines where the valves are directly driven by the camshafts over flat tappets, just like what AJ26/27 engines have. There have been many reported cases of excessive camshaft wear on such engines (especially Porsches) when using modern engine oils which have much reduced ZDDP content due to regulations by the Environmental Protection Agency (EPA), especially after the reductions introduced since about the year 2000.

On the other hand, I noticed that AJ26/27 engines have much softer valve springs than what I have seen on other flat tappet engines so the Jaguar camshafts may not suffer too much with reduced ZDDP oils. Anyhow, I prefer to be on the safe side so I use 4T oils which have about 1,200 ppm ZDDP (recommended as a minimum for wear protection of camshafts on flat tappets) whereas most current car engine oils have their ZDDP content reduced to some 600-800 ppm.

 

Interesting oil discussion: but . . . has the car started yet? Might try ether (for starting in very cold weather).

 

Sorry for the delay. Daughters birthday halted late night car work. New plugs installed (just because I was gonna do that anyway). Oil changed (needed anyway). Ready to try bore wash fix. Will do so in a moment. In the mean time a quick question - I went in the fuel tank just to make sure the problematic clamps and hoses were secure on the fuel pumps. Inside there are the 2 pumps, hoses from each going into a Y fitting and 1 hose to the bottom of the tank were it heads to the front of the car. Next to that at the bottom of the tank is another similar hose going to a similar metal pipe. Does anyone know what this second hose is? I ask because the hose is severely swollen. I actually poked at it w/ my finger and I think I poked a hole in it its that bad. Needs to be replaced. What is this?

 

, bore wash procedure completed one time...……..no start. I got a logic probe which is computer safe and will allow me to check for power and ground at the injectors. I guess that will be my next step. Timing is confirmed good, spark good, compression good, We've still got a fuel problem. I will start with that and see what happens.

 

Don't give up after one try. It sometimes takes a few tries. Give it a couple more before surrendering to somthing else.

 

ok so logic probe on injector results are in...……...don't really know how to interpret the results because I don't yet know the specifics of the operation of this system (guess I need to research). So I used a thin knitting pin to gain access the one of the injector wires. Logic probe indicated continuity with ground and the green light was a bit faint not as bright as if I just went to a random chassis ground. Turned the key over while monitoring probe and the ground flashed brighter at a pace equal to the speed of engine cranking. Seems this indicates a switching or pulsing that we want to see. Probed the other wire and got the exact same result - a faint ground connection that pulsed between faint and strong with engine cranking. Anyone familiar with this system? I was expecting to see power at 1 of the 2 wires and ground at the other. I got ground at both that pulsed between faint and strong connection as I cranked engine? Does this seem correct.

 

I'll try it a couple more times. I feel bad for that poor little starter.....Running out of time so I will update later tonight.

 

The second hose, according to your description, appears to be part of the fuel return line. This is the line from the fuel pressure regulator that enters the tank near the fuel delivery line (the one to which the "Y" fitting is connected) and probably has a length of rubber hose connected to it inside the fuel tank. Does the hose you poked have one end free inside the tank? If so badly deteriorated, it will keep on releasing flakes/chunks of rubber that will clog the pump strainers again.