No worries. I was just relieved as it looks like some major surgery going on. I’ll stop shaking now…
let us know…with the new plugs…no reason to chase the goose more…if plugs makes it run…BUT IF NOT…then plenty of comments will come. Hope thats it. (By the way…back in the old days plugs were cleaned either in little sand blast boxes at the gas station,or in Carbont Tet…neither should be done. Nick
I checked the cams and they are in the correct position. I put it TDC at #6 based on the distributor and the timing marks. From the oil filler hole I could see the notch was at the top and the cam lobes at #6 were orientated outwards.
The plugs are also not the issue. I switched the plugs with the ones in my MGC and the MGC ran well. So I now have the plugs from my running MGC in the XKE. I checked the spark again and see it at the plugs. I pulled off the gas feed to the Strombergs and turned it over and it is pumping gas. It did seem a little closer to starting and got some minor pops but did not fire up. I did see a bit of smoke coming back out the carbs after a pop.
I tried it with choke and also with no choke and accelerator to the floor but no luck firing up.
Not sure of the next step to take so any input appreciated.
Jay
In general, when you combine gasoline, electric spark and air, you should get SOME reaction. You say it won’t start, but are you getting any signs of life?
If not, I suspect one of the three components are not getting to the cylinder. Are the plugs wet? If you’ve tried starting for awhile they should show some wetness.
If you know you have fuel in the cylinder, with no signs of life, then I suspect your spark is not getting there or is not strong enough.
Hth
Robert
Hi Jay…try a quick compression test…there are lots of things that can go wrong when replaceing shims and camshafts…especially clashing valves… Steve
The top (straight) side of the pointer is the correct datum.
The damper is precisely keyed to the crank, so the vernier is fixed. The pointer itself is secured to the timing cover with two bolts with essentially zero play, perhaps a fraction of a degree, so if it’s bent out of position - from what I can tell by your pic it appears to be perpendicular and straight - it will be obvious, and even then I’m unable to visualise the pointer bent sufficiently to be six degrees out. Two possibilities come to mind. The less likely is the damper is out of alignment because the woodruff key in the crank or the woodruff key in the cone is either missing or sheared. The more likely is you’re not really at TDC and if you have set your cams up accordingly your valve timing will be out of whack.
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FYI, on my 1970 4.2 the holes in the pointer are oblong so it can be adjusted.
Makes sense. It’s been long enough since I did the rebuild that I may have forgotten the pointer is adjustable, as in achieving true TDC and then positioning the pointer precisely. In which case it still comes down to confirming TDC and confirming the cams are synchronised correctly before proceeding.
Many thanks for the help.
I will run a compression check tonight to make sure all is well with all cylinders. Also re-confirm I am at TDC #6 and check the cams slot is vertical with the relevant tool. I did this before removing the cams but good to double check everything again. I think whoever set the timing pointer used the angled side rather than the straight side, as this is close to zero degrees. I will therefore use the angled side for now if it is correctly at TDC and adjust the pointer once I have the car running.
I have what looks like a good spark and looks like I have gas so could the timing have changed after tightening the chain ? Seems like taking out a little slack should not affect the timing too much but I guess if it was right on the edge, this could have taken it over.
After checking compression, gas, spark, TDC. Would the next step be checking the static timing to see where it is ?
Many thanks for the responses. I was quite dissolutioned on Sunday but am hopeful to get it working again now. And learning a lot in the process.
Thanks
How do you define having gas? Fine, the pump is delivering, but that wouldn‘t have me satisfied that gas is making into the cylinders. Are the plugs wet? My engine was sitting for months w/o gas in the carbs and I had a really hard time before it initially started. It took a prime spray of brake cleaner or the like to start and would die on me. Took a while til it would actually run on it‘s own. No longer a problem but boy it took patience and a lot of squirting direct in the carbs. Make sure gas is making it all the way to the cylinders.
Martin
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Jay, establishing true static TDC is the very first thing that needs doing before anything else, otherwise you’ll risk compounding the problem. If you plumb the archives you’ll read several discussions on how to go about it. I set my short block at TDC before remounting the head and then didn’t touch the crank until after setting up the cams. You may be right that the pointer is misaligned but it’s important that you confirm this. What I do not know, because my experience with and knowledge of the XK engine is limited, is how much the camshafts have to be out of sync with stroke before the pistons foul and bend the valves.
Establish TDC first, static, then move on to the next troubleshooting steps.
so…hoping your compression test is OK…then , yup agree with Nick Saltarelli…verify TDC is really TDC…#6 (front) on compression. Find roughly top on compression…a small rubber stopper in plug hole will blow out rather impressively. then a dial guage…even a wood dowell with many marks to find the "center’ of top dead center…check cam position, check distributor position which at this point should then be at whatever advance setting you use…see if the timing marks/pointer are correctly placed…both for TDC and the degree of advance you use. Check dizzy cap to plug wires are in proper firing order, counter clock and are to the proper plug. easy to have a few switched. check dizzy cap inside that upper central pin is not stuck up…and is free. Verify everything again. Nick
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Thank you all for the information, I will go through it again and verify everything. Frustrating thing is this was a good running and driving car before the valve adjustment. I had rebuilt the carbs a few months back and it was running better than ever.
So my plan of action this weekend is to go over everything again in this order:
- turn over and check for wet plugs
- remove plugs and perform compression check
- find TDC#6 (cyl 2/3 equal height)
- check CAM’s notch with CAM tools (notch straight up and lobe at #6 pointing out)
- check timing pointer position and adjust to zero if needed
- set crankshaft to 10 degrees before TDC
- set static timing
- fingers crossed
- engine starts
Jay
Good luck for the weekend Jay!
check for proper plug wire to dizzy cap in firing order 1 5 3 6 2 4 (6 2 4 1 5 3) , counter-clock…dizzy cap, and to correct plug, #6 cyl is front…so on the dizzy cap the #2 plug wire will be the first one counter clock of #6, .and that contacts of wires are good at cap, center contact inside cap is free to move on its spring. (Note that due to piston at top “dwell”, that is reaching top to start of down, it is very difficult to find the halfway point of that dwell exactly…the movement is miniscule…but it is close enough to verify the TDC if it is correct as is…if it is not correct then there are piston stop methods) Ohh…BTW the equal height of adjacent cylinders method has problems…quite a good thread on this on the forum…due to domed piston tops and spark plug holes not centered over the same places etc etc…)
Nick
After carb rebuild, mine would not start. Turned out the float bowls were full, but the rest of the carbs were dry. I started it on carb cleaner, to generate enough vacuum & that fixed it.
3.? I hereby give up.
All the best.
Sorry Nickolas. Was not trying to get you frustrated, I was trying to gather the information from all responses into a sequence of checks. After re-reading your response I see that TDC should be first thing before anything else.
Apologies Jay
Pardon my testiness.
I’m no XK engine expert. Far from it. But there are some things that are basic to IC engines. Valve synchronization with stroke needs to be so accurate the valves are opening and closing at precisely the right time(s). Not like ignition timing that’s flexible. From what you’ve posted there’s some small possibility your crank and cams are six degrees out of synchronization, if so it’s comsiderable. The compression test assumes both valves are closed at the very top of the compression stroke. If either of the valves is even a little open the compression test would read low. TDC is the First thing to verify.
I would prefer one of the resident engine experts take over. You know who you are.
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Just wanted to say a big thank you to everyone who has given information and advise. Its much appreciated, and I am learning a lot.
Spent a little bit of time last night checking the TDC #6 settings.
To set TDC#6, I set it close and then used #2/#3 cyclinders to determine when they were at the same height. At TDC#6 the timing pointer was pointing to 2 degrees advanced but the cam slots were not vertical at this point. Based on when i did the valves gaps, the cam slots were vertical at about 4 degrees after, so as Nikolas suggested it looks like the cams are off by about 6 degrees.
I tried to adjust the pointer to zero but it cannot be moved up any further. So I will start reading up on how to adjust the cams sprockets and dive even deeper.
Cylinder2 to find TDC#6
Cylinder3 to find TDC#6
Timing Pointer at TDC#6
Exhaust Cam at TDC#6
Inlet Cam at TDC#6
Distributor at TDC#6
Jay