yeah but mowers have fiddly poorly made carbs and connections. Also, them not starting is just a fuel issue but your post made it sound like it is a hopeless lost cause and by now the rings are garbage, with the only impied cause being ethanol.


I have an additional V12 that I purchased for $100 and it turns over just fine. I understand how quickly ethanol turns to gunk and how it affects fuel systems, but there is something wrong if your cylinders are coated in ethanol. That should have been burnt last time you were running the engine.

Cleaning and freeing sticky rings is relatively unrelated. So far it sounds like the OP just has fuel/air issues but hasn't done much to work them out.

dorschman, you made it sound like you quit after the starter fluid issue. Try starting it and if it doesn't go, try it with the throttle in various positions. When I first got my XJS started it was with the throttle around the spot that would normally be 4500 rpm. I had to hold it there and very very gradually let it down until it finally let go and actually idled at a regular throttle position.

Being only 3 years it may how more ethanol in it, so there is a change your injectors are sticky if your fuel pressure is fine. So if you have no luck getting it started pull them and clean them out.

I did like you said when I got my v12 and just ran it for about 30 minutes a day until it was really well settled

 

I didn't mean for it to sound hopeless. I just know from experience, what I saw. When I took the injector rail off of this 94 6.0, and ran carb cleaner through it, the injector spray pattern changed DRAMATICALLY. 5 of them not functioning at all. No amount of starting fluid would have ever made those injectors work. And fuel passing over the top of them, fresh or not, simply couldn't have freed them up. I am sincerely happy for your luck with getting the Jag running by just starting it a few times. I was trying to not only determine if this engine would start, but if it were worth using as a donor engine for my 5.3 that dropped a valve seat sitting in the driveway.

I am only a enthusist, with a passion for Jags, especially the V12. Have rebuilt two V12, worked on countless of them. Am fully engaged in using this 6.0, and installing a 5 speed, with either megasquirt, or Emerald EFI and ignition controller. If you want to know the true condition of a engine, it takes more than starter fluid, and crossed fingers. My rings on the 6.0? Who knows. I only know know that it has a consistant 240psi on every cylider but 1. It has 190-195. I have a long way to go on this current project, and may still tear the engine down, just to find out why it has lower compression on one cylinder.

 

yeah, im not surprised about the backfire given his description of the amount. Usually you just want to spray a little and only add more if it doesn't seem to be enough after trying to start it.

I agree the ethanol is really terrible in how it keeps and a car that has been parked in the last 10 years is probably worse off than a car sitting longer because of the ethanol content.

I would like to clean my injectors, but my car is a daily driver, so i am always afraid of something breaking and having to wait for the mail. My other engine is at my dads house, so I will wait to get the rail and injectors off of it. I am excited to see what difference it could possible make.

Just out of curiosity, which cylinder is lower on compression?

 

4B. My compression was all over the board to begin with.

 

For trying the throttle in various positions does it matter if I hold it open with the accelerator pedal or have someone hold it open at the engine?

Basically will the accelerator pedal affect anything else that holding the throttle open manually would not?

 

No difference
Greg

 

No luck with the throttle at various positions.

So- I am in the process of printing out the chapters of the 700 page book and will proceed to read them to the best of my ability. I have the Haynes manual and have ordered the "Operation Manual" mentioned in Kirby's book. I have local friends willing to help along the way where they can too.

My tentative plan is to do whatever is needed to get down to the spark plugs so I can do a compression test. If that seems ok then change the plugs and clean/ do something to the fuel injectors.

This may take me forever but I have time and effort so that's ok.

Any other thoughts as to other things I should think of?

I know that for someone knowledgeable this may sound like a really frustrating approach but I have to start trying somewhere.

I'm also working on saying "jag ewer"

 

The reason the car is not starting is nothing at all to do with the odd cylinder maybe being down on compression. I think worrying about this is for later.

If it tried to start on ether, then begin your campaign from there. I think this would be the best way to proceed:

• If you have not done so yet, change the plugs
• change the HT leads
• then check to see if there is a GOOD BLUE spark being generated at each plug (lots of ways to do this, but having a friend turn the starter key while you with INSULATED pliers hold each HT lead in turn 1/4 inch from the head is one way) If no spark, post again. You have a Marelli ignition system and guys here can explain how to check it.
• If this is Ok then fuel is your next point of investigation. If fuel is roaring out of the supply pipe (as you indicated earlier) blocked or not functioning injectors is the next point of investigation. You can test them by (a) disabling the ignition and then (b) remove an injector from the engine but not the fuel rail, and poke it into a jamjar and again get a friend to turn the starter key. You should see a mist of fuel spray out in pulses.

If the injectors do not work, then test the electrical circuit they are plugged into to see if they are receiving the correct signal from the ECU and loom. If you decide to do this post again and guys will explain how to test the injector circuit.

If the injector electrics are OK then the injectors are blocked (extremely likely) so they need to be cleaned. You could start by removing them and soaking them in injector cleaner for 48 hours. This very well might work. Or have them professionally cleaned. Whichever you try, refit them with new flexibles.

If the engine has fuel and spark it will start, even if it will not run perfectly. In 2008 I started a 1985 car that had not been started since 1990 and once the ignition was sorted it started and ran perfectly.


Good luck
Greg

 

This car was parked for a reason. The only reason I suggest a compression check first, is because it is FREE, and it will tell you how far you need to go. Rent the tool from one of the national parts stores if you don't want to own or purchase it. Once you have done the compression check, if the engine has no compression on one cylinder, it may have very well dropped a valve seat, and was parked. I'm just saying you should diagnose the condition of the engine before puuting a lot of time and money in it, just to find out it had bidder problems.

 

So- I have the cruise control bellows moved, the a/c compressor moved. Researching how to move the throttle pedestal.

I have a side trip question though- I found a nice snug rodent nest under the cruise control bellows and it looks like they used some of the wire coating for part of their snug little nest. I don't see any wire actually exposed but the individual wires are in some places.

Is there a way to use something to repair the existing protecting covers for the individual wires or do they likely need to actually be replaced?

Pictures included (I think).

 

another question- it seems according to Kirby's book that NGK spark plugs are the spark plugs most people seem to like. But I am not sure how current that is.

I bought some plugs from Advance Auto locally and they are AC Delco. I need to figure out how to set the gap to 0.025 but I will get to that.

I found these on a large web site that is named after a large river in South America-

NGK (1094) BR7EFS Standard Spark Plug
Brand NGK
Item Weight 1.6 ounces
Product Dimensions 4.4 x 2.2 x 2.1 inches
Item model number BR7EFS
Manufacturer Part Number BR7EFS

Is this a recommended or apparently appropriate plug?

I can return the AC Delco ones and buy these- I am just not sure if it makes that much difference.

thank you-

erik

 

Yet another question- I have a set of Bosch HT wires that are 7mm.

Before I was farther into reading I did not know there were choices of thickness (insulation, diameter, whatever?).

Would it be a significant advantage to return these and use 8mm or 10mm wires?

sorry about the multiple replies- it seems the more I read and learn the more I have questions.

 

BR7 EFS well worth buying. return the others

The insulation on the wires can be repaired, bit of a bodge, but OK. From the pics it looks like the outer covers only have been eaten! Carefully look at the pvc insulation covering the actual copper strands. If any of this is eaten away, wrap it with PVC insulating tape wound round the copper/chewed bits.

8mm HT leads of a decent make are a very good idea, but not absolutely necessary. OEM ones will be fine too. The important thing is that they are new. The Bosch leads will do I am sure (unless they have carbon cores which are a total disaster) but are they the right lengths for the V12? Make a clear diagram of where each lead starts and finishes before removing any, best to change one at a time (assuming they are in the right place to start with) !

Removing the pedestal a pain, but very good idea. Unbolt the little bolts you can see at the top and move the capstan. Then (this is what I did) get a 7/8ths ring spanner, heat and bend the ring end to a right angle to get onto the pedestal bottom fixings. grip the end poking up with a large pair of grips and undo!

Good luck
Greg

 

I took apart a great many things but I think I now have access to the "vee".

Do these images look right for beginning to try to blow out crap from around the plugs, change the plugs, change the HT wires, repair the rodent damage, and do a compression test?

 

by the way this is the "workspace" if anyone has suggestions or comments-

 

Well, its for sure you have Marelli ignition. I will stand by my recommendation of a compression test, before you spend another penny. To me, its sort of a starting point with knowing the condition of the engine. I again will say, the car was parked for a reason. If that reason was a dropped valve seat, even the expense of a set of plugs is a waste, unless you plan on doing a major teardown, rebuild of the heads. With that said, if the engine has decent compression, next thing for me, is to check for fire. On my non-running Marelli car, I put the coil leads, (the distributor ends), next to metal, and turned then engine over. I had fire on one side (A), continuosly. B side would drop out after 3-6 seconds. On my car, it turned out to be the rear crank sensor. The Marelli ignition isn't near as intimidating as it was when I purchased the car.
I just know it takes 3 things for a gasoline engine to run (if its in decent mechanical condition). Fire, fuel, and air. To me, in that order. Establish mechanical condition, then make sure you have fire, then fuel, and presumptively, you don't have a blockage on the intake side, and the car "should" run. My offer is open to talk.

 

so as I read about doing a compression test I have come across this in the Kirby book-

COMPRESSION CHECK: First, a brief description of how to properly perform a compression check on any car: The battery and starter must be in good condition. All of the spark plugs should be removed. Power to the ignition system should be disconnected, since an electronic ignition system may be damaged trying to fire with the spark plugs disconnected. And the throttle should be held at least part way open, usually by jamming something in the linkage. On a car with EFI, it would also be helpful to disconnect the power to the EFI system or fuel pump to prevent fuel flow. With a compression gauge fitted to one spark plug hole, the engine should be turned on the starter through several compression strokes, until the reading stabilizes at a peak value.

On the XJ-S, it would be most helpful to have the type of compression gauge that screws into the spark plug hole and has a lengthy hose. Trying to hold the press-in-place type on this engine is not easy. Also, since the A/C compressor usually has to be removed to get at the front plugs, you will probably have to run the test with a dangling drive belt; try to position it so there is no tension on it, and the crank pulley can turn within it without driving it.

On the US-spec pre-H.E. engine, the readings typically will be about 130-150 psi. The US-spec 5.3 liter H.E. engine has 11.5:1 compression, and will read about 200-220 psi. Note that readings will be lower at high elevations.

Keep in mind, however, that the absolute values are not as important as the relationship between them. There are dozens of factors that could affect the absolute values (including the calibration of your gauge), so if your readings are all a little higher or lower than the above, don't worry about it. But they should all be nearly the same; one significantly lower than the others is not a good sign.

If one cylinder reads low, it is customary to add a couple tablespoons of motor oil into that spark plug hole and test it again. In theory, the oil will temporarily seal bad piston rings but won't seal a burned valve, so this test may indicate the level of disassembly needed. Of course, the oil probably won't seal a burned piston or a hole in a cylinder liner, so the results are best taken with a grain of salt. Either way, the head has to come off."


Since I had to take the throttle pedestal off to gain access to the rear plugs the throttle is all apart. I guess I could have someone on each side try to manually pull it open at the air filter housing but how critical is this to the compression test?

And I'm nervous about having all the plugs out at once. I had planned to do one at a time and put the new plug in after each compression test on each cylinder? Is this reasonable or do I really need to have them all off at once?


And- if I remove the two central HT lines from the distributor is that sufficient (and safe) to disable the ignition?

My understanding is that there is a fuse that I can access in the trunk to disable the fuel pump- I will read up on that a little more too.

 

Not sure of the reluctance to pull all of the plugs at once......its just a assembly of many parts, and if you've come this far, all the plugs out is just the next step. I don't really understand having to hold the throttle open, when you have all the other plugs out. I tried it both ways, and there was no difference either way.
You're doing great. Don't worry. The compression test will do exactly what the book describes. It will give you a much better knowledge of the condition of your engine.

 

As I begin to change the spark plug wires (plugs and compression tester are not here yet) I notice that my new Bosch plugs are not all the same angle as the ones in the car- namely it appears to be the front most and back most plugs (1 and 6 both sides I think) have a right angle where the plug wire attaches to the plug.

My new Bosch ones are all straight at the wire/ plug attachment.

Is this a problem (especially under the a/c compressor) and I need to buy different wires or will this be ok space wise?

In the picture the old wire is on the left and the new one is on the right for reference.

And- the new set does not include the two wires that attach to the center top of the distributor- they are both very short. Also pictured. Do these not need to be replaced?

 

I feel you do need the angled boots on at least the front plugs because of the A/C compressor. I can't say the straight ones won't work, yet "may" begin to short to ground pretty quickly as the heat begins its work on the new boot/wires being right up against the compressor.

Not much need to worry with those wires until compression test is done. The neat thing about the Marelli cap, is that it is clearly marked as to which wire goes where. I feel completely comfortable pulling all of the plug wires with my Marelli car. I promise the apprehension goes away, the more you work on your car. I'm really hoping that the compression test goes well for you. As Kirby said, one cylinder much lower on compression certainly means more teardown. If this engine has a mechanical failure in a valve seat, valve, those plug wires will become a very very low priority.