Could someone point me in the right direction as to how to perform a timing check on a V12, please? For complete beginners. One is ashamed to admit that one hasn't carried out this task before!
I have the Repair Operation Manual, a timing strobe and I've located the pulley and timing plate.
Manual refers to 12 degrees BTDC. Is this at a particular rpm?
I've searched the web but cannot find a basic guide relating to a V12 distributor.
In case someone asks, no the ignition system hasn't been upgraded. Yet.
Thanks.
Timing for dummies
#2
Hi Marcus,
You don?t say in your post whether the car is running satisfactorily or not. If not, best to start with static timing. Remove the distributor cap. Look at the ferrite rotor (the circular plastic plate, below the rotor arm; normally white). This should have a notch with ?No. 1? written next to it. This identifies the ferrite rod (embedded in the rotor), which, as it passes the sensor, aligns No.1 ?A? bank cylinder lead with the rotor arm. Next identify the ?A? bank timing mark on the front pulley and rotate the engine until it aligns with the 12⁰ BTDC mark on the timing plate. This is only visible from under the car. You need to be sure the No. 1 cylinder on the ?A? bank (the right hand bank viewed from the driver?s seat) is on firing stroke. If all is close to the correct setting, the timing mark on the rotor will be close to alignment with the sensor. Step 86.35.20 in the original workshop manual describes this and shows a picture, you say you have the manual, if not it?s available on the Forum Knowledge base ? look in the electrical section. If the notch is approximately 180 degrees from the sensor, you are on exhaust stroke and the engine has to be rotated until all aligns. If however, it is neither close to the sensor nor close to 180 degrees from it, your distributor is fitted incorrectly and you will have to set it, starting with getting the No. 1 ?A? bank cylinder to 12⁰ BTDC on firing stroke. Hopefully though, all will be well and you can ignore the next paragraphs moving straight to the static timing adjustment.
To find compression stroke, I put my finger over the spark plug hole and rotate the engine until I can feel the compression forming as the timing mark approaches the timing mark (easier to do than explain), indicating the piston is rising, compressing the air in the piston with both valves closed. Next fit the distributor ensuring the marks align as described earlier. If you don?t understand this, best to get someone to do it for you and explain as they go.
With the Engine at 12⁰ BTDC (?A? bank), firing stroke, if the notch of the rotor aligns perfectly with the sensor, then good, if not, you need to adjust. Coarse adjustment is by accessing the three Allen screws locating the distributor, accessed through the slots in the rotor, again these are shown in the manual at step 86.35.20. Also visible in the picture is the fine adjuster, consisting of a screw adjuster, with a lock nut. This is directly opposite the vacuum unit. Ideally, this should be slackened off and the fine adjustment (achieved by rotating the screw), placed in the mid-point, before aligning the notch/sensor and locking the three Allen screws. This allows the maximum amount of fine adjustment in either direction when Dynamic timing begins. With everything set up, access to the screws is easy and all will be fairly straightforward, if not, then someone has been messing with the settings and it might be best to remove the distributor and start from scratch.
At this time, also check the air gap between rotor and sensor, 86.35.18 in the manual shows this ? the gap should be 0.021? to 0?022? in.
Dynamic timing is no different in principle to any other car. Fit the sensor lead from the strobe to the No. 1 ?A? bank lead and set up the gun in accordance with manufacturer?s instructions. Ideally, pick out the marks on timing pulley and plate in white ? Tippex is ideal. Disconnect the vacuum unit connection, start the car and allow it to warm up sufficiently so you can run it at 500-600 rpm, you should have to back off the idle screws to achieve this, so be methodical and note how much you adjust each ? do the same to both banks and restore by the same amount afterward. With the car running at the correct rpm, check timing (again, 12⁰ BTDC, ?A? bank) and adjust if required by backing off the locknut on the fine adjuster, using a screwdriver to adjust and lock the locknut when complete. Make a final check after locking the nut as this can affect the result. All this is possible with one person, but easier with two. If you have difficulty viewing the timing plate, then lift the front wheels onto blocks of wood for better access. Take all reasonable precaution to chock the car, start out of gear(!) and be aware of the danger of moving parts under the car when crawling under to view. Easier yet would be to do it on a four post ramp.
Reconnect the vacuum, reset the idle and you are done, although it may be best at this point to tune the carbs ? another story!
Hope this is clear, if long winded.
Regards,
Simon.
You don?t say in your post whether the car is running satisfactorily or not. If not, best to start with static timing. Remove the distributor cap. Look at the ferrite rotor (the circular plastic plate, below the rotor arm; normally white). This should have a notch with ?No. 1? written next to it. This identifies the ferrite rod (embedded in the rotor), which, as it passes the sensor, aligns No.1 ?A? bank cylinder lead with the rotor arm. Next identify the ?A? bank timing mark on the front pulley and rotate the engine until it aligns with the 12⁰ BTDC mark on the timing plate. This is only visible from under the car. You need to be sure the No. 1 cylinder on the ?A? bank (the right hand bank viewed from the driver?s seat) is on firing stroke. If all is close to the correct setting, the timing mark on the rotor will be close to alignment with the sensor. Step 86.35.20 in the original workshop manual describes this and shows a picture, you say you have the manual, if not it?s available on the Forum Knowledge base ? look in the electrical section. If the notch is approximately 180 degrees from the sensor, you are on exhaust stroke and the engine has to be rotated until all aligns. If however, it is neither close to the sensor nor close to 180 degrees from it, your distributor is fitted incorrectly and you will have to set it, starting with getting the No. 1 ?A? bank cylinder to 12⁰ BTDC on firing stroke. Hopefully though, all will be well and you can ignore the next paragraphs moving straight to the static timing adjustment.
To find compression stroke, I put my finger over the spark plug hole and rotate the engine until I can feel the compression forming as the timing mark approaches the timing mark (easier to do than explain), indicating the piston is rising, compressing the air in the piston with both valves closed. Next fit the distributor ensuring the marks align as described earlier. If you don?t understand this, best to get someone to do it for you and explain as they go.
With the Engine at 12⁰ BTDC (?A? bank), firing stroke, if the notch of the rotor aligns perfectly with the sensor, then good, if not, you need to adjust. Coarse adjustment is by accessing the three Allen screws locating the distributor, accessed through the slots in the rotor, again these are shown in the manual at step 86.35.20. Also visible in the picture is the fine adjuster, consisting of a screw adjuster, with a lock nut. This is directly opposite the vacuum unit. Ideally, this should be slackened off and the fine adjustment (achieved by rotating the screw), placed in the mid-point, before aligning the notch/sensor and locking the three Allen screws. This allows the maximum amount of fine adjustment in either direction when Dynamic timing begins. With everything set up, access to the screws is easy and all will be fairly straightforward, if not, then someone has been messing with the settings and it might be best to remove the distributor and start from scratch.
At this time, also check the air gap between rotor and sensor, 86.35.18 in the manual shows this ? the gap should be 0.021? to 0?022? in.
Dynamic timing is no different in principle to any other car. Fit the sensor lead from the strobe to the No. 1 ?A? bank lead and set up the gun in accordance with manufacturer?s instructions. Ideally, pick out the marks on timing pulley and plate in white ? Tippex is ideal. Disconnect the vacuum unit connection, start the car and allow it to warm up sufficiently so you can run it at 500-600 rpm, you should have to back off the idle screws to achieve this, so be methodical and note how much you adjust each ? do the same to both banks and restore by the same amount afterward. With the car running at the correct rpm, check timing (again, 12⁰ BTDC, ?A? bank) and adjust if required by backing off the locknut on the fine adjuster, using a screwdriver to adjust and lock the locknut when complete. Make a final check after locking the nut as this can affect the result. All this is possible with one person, but easier with two. If you have difficulty viewing the timing plate, then lift the front wheels onto blocks of wood for better access. Take all reasonable precaution to chock the car, start out of gear(!) and be aware of the danger of moving parts under the car when crawling under to view. Easier yet would be to do it on a four post ramp.
Reconnect the vacuum, reset the idle and you are done, although it may be best at this point to tune the carbs ? another story!
Hope this is clear, if long winded.
Regards,
Simon.
Regards,
Simon
Series III FHC
Simon
Series III FHC
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#3
Hi Simon,
Thank you for the detailed guide. I should have mentioned that the car runs very well in the drive, but is a little hesitant underload whilst accelerating, in all gears. At least it was both when I test drove the car before I bought it and also 10 days ago driving into the village for its MOT. I'm awaiting a registration from the DVLA, so am unable to go for a decent drive to check her out properly.
So I spent time yesterday on the timing and tuning and discovered first of all that the timing was way advanced at about 23 BTDC. Managed to adjust this back down to 12. The previous owner hadn't tightened the distributor lock nut and as a consequence it was free to move on its own accord.
I then moved on to carb tuning with the aid of an STE synchrometer and the owners manual. I was proceeding quite well balancing the right side, but failed trying to do the same to the left. To be more precise, the problem arose when the manual moves on to tell you to adjust the balance screw to bring the rear left up to the same setting as the front left, which had already been balanced with the right side. When I altered the balance screw it only increased the airflow on the front left and not the rear. At this point I packed up and called it a day. It's probably me not following the instructions , but I did wonder if the balance mechanism was somehow inverted as it looks very different to the right side.
A kind, fellow V12 owner let me have the special carb adjustment tool for altering the mixture. I think its running quite rich at the moment as the plugs are sooty. So if I can keep my nerve on this issue then I'll look into this sometime.
If tuning doesn't improve the hesitant acceleration I'll look into the ignition side of things. It still has the original ignition amplifier etc.
Thanks again.
Thank you for the detailed guide. I should have mentioned that the car runs very well in the drive, but is a little hesitant underload whilst accelerating, in all gears. At least it was both when I test drove the car before I bought it and also 10 days ago driving into the village for its MOT. I'm awaiting a registration from the DVLA, so am unable to go for a decent drive to check her out properly.
So I spent time yesterday on the timing and tuning and discovered first of all that the timing was way advanced at about 23 BTDC. Managed to adjust this back down to 12. The previous owner hadn't tightened the distributor lock nut and as a consequence it was free to move on its own accord.
I then moved on to carb tuning with the aid of an STE synchrometer and the owners manual. I was proceeding quite well balancing the right side, but failed trying to do the same to the left. To be more precise, the problem arose when the manual moves on to tell you to adjust the balance screw to bring the rear left up to the same setting as the front left, which had already been balanced with the right side. When I altered the balance screw it only increased the airflow on the front left and not the rear. At this point I packed up and called it a day. It's probably me not following the instructions , but I did wonder if the balance mechanism was somehow inverted as it looks very different to the right side.
A kind, fellow V12 owner let me have the special carb adjustment tool for altering the mixture. I think its running quite rich at the moment as the plugs are sooty. So if I can keep my nerve on this issue then I'll look into this sometime.
If tuning doesn't improve the hesitant acceleration I'll look into the ignition side of things. It still has the original ignition amplifier etc.
Thanks again.
1971, S3, 2+2, manual. Red.
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#4
Hi Marcus,
I have sent a PM so you can contact me and I can send some files to you which might help. However, in response to your post, I believe you may have an air leak, a common problem on a car with as many possible sources of leak as the V12 Jaguar engine has. I had to check my car fully for leaks recently and lost count of the sources of possible leaks I found and tried to correct, but in the end the car is much better.
Regards,
Simon
I have sent a PM so you can contact me and I can send some files to you which might help. However, in response to your post, I believe you may have an air leak, a common problem on a car with as many possible sources of leak as the V12 Jaguar engine has. I had to check my car fully for leaks recently and lost count of the sources of possible leaks I found and tried to correct, but in the end the car is much better.
Regards,
Simon
Regards,
Simon
Series III FHC
Simon
Series III FHC
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#5
Finally sorted the uneven/rough acceleration under load issues.
After methodical step by step examination of possible causes with the help of the ROM and experienced advice from fellow owners, notably, Peter, Simon and Marek the problem has been resolved.
Working on the basis that one starts at the beginning with timing, this is what was checked first. It was way out at approx 20 degrees BTDC at idle, basically due to the fact that the locknut on the adjuster on the distributor was so loose that it was moving about all over the place. Well, this wasn't helping anyway.
Then moved on to tuning the carbs. All 4 were way out, so reset with the help of a synchrometer.
Mixture checked next and again there was quite a discrepancy between all 4, mainly rich, but needles stuck also.
Then checked all leads fitted in correct order and condition of said leads.
Inline tester connected between each plug and lead. All 12 lighting up the flashing bulb. Seems OK!
Quick illegal test drive round the block. No reg plates you see. However, taxed MOT'd and insured. I just needed to know.
Still major issues in accelerating .
Now I'm loosing sleep over the cost of going down the ReOpus/Lumenition route.
Actually, I'll just fit 12 NGK BPR6ES plugs, although it can't be something this simple surely.
Indeed it was. Quick test drive round the lanes and she pulled like a train. Different car now. Deep joy. :D
After methodical step by step examination of possible causes with the help of the ROM and experienced advice from fellow owners, notably, Peter, Simon and Marek the problem has been resolved.
Working on the basis that one starts at the beginning with timing, this is what was checked first. It was way out at approx 20 degrees BTDC at idle, basically due to the fact that the locknut on the adjuster on the distributor was so loose that it was moving about all over the place. Well, this wasn't helping anyway.
Then moved on to tuning the carbs. All 4 were way out, so reset with the help of a synchrometer.
Mixture checked next and again there was quite a discrepancy between all 4, mainly rich, but needles stuck also.
Then checked all leads fitted in correct order and condition of said leads.
Inline tester connected between each plug and lead. All 12 lighting up the flashing bulb. Seems OK!
Quick illegal test drive round the block. No reg plates you see. However, taxed MOT'd and insured. I just needed to know.
Still major issues in accelerating .
Now I'm loosing sleep over the cost of going down the ReOpus/Lumenition route.
Actually, I'll just fit 12 NGK BPR6ES plugs, although it can't be something this simple surely.
Indeed it was. Quick test drive round the lanes and she pulled like a train. Different car now. Deep joy. :D
1971, S3, 2+2, manual. Red.
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#6
Hi,
I have just been through the same as you, getting my V12 up and running after 10 years of inactivity.
After stripping and cleaning the carbs, setting the timing, new leads, cap, Reopus ignition, coil and getting the fuel pump pumping properly it would still not run well and wouldn't pick up smoothly from idle.
I was starting to give up on it so gave Angus Moss a call and he asked if I'd put in new plugs. I hadn't because they had been changed just before it was laid up and when I inspected them they were nice and clean.
anyway, he said to change them anyway so I put a set of NGK BPR6E (not the S) and as with you it was cured !
The car is now running nicely, other than on start-up as I need to adjust the choke.
Blumin quick car! :D
I have just been through the same as you, getting my V12 up and running after 10 years of inactivity.
After stripping and cleaning the carbs, setting the timing, new leads, cap, Reopus ignition, coil and getting the fuel pump pumping properly it would still not run well and wouldn't pick up smoothly from idle.
I was starting to give up on it so gave Angus Moss a call and he asked if I'd put in new plugs. I hadn't because they had been changed just before it was laid up and when I inspected them they were nice and clean.
anyway, he said to change them anyway so I put a set of NGK BPR6E (not the S) and as with you it was cured !
The car is now running nicely, other than on start-up as I need to adjust the choke.
Blumin quick car! :D
Richard
____________
1972 S3 2+2 - Black with Red leather, 4 Speed and Wires
1966 S Type 3.8 MOD - ex South Africa
1994 XJS V12 coupe - 59,000 miles
____________
1972 S3 2+2 - Black with Red leather, 4 Speed and Wires
1966 S Type 3.8 MOD - ex South Africa
1994 XJS V12 coupe - 59,000 miles
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#7
I'm glad to hear you are nearly there now Marcus and can start enjoying your beast 
64 S1 4.2 OTS 1E10012 73 S3 2+2 manual 2013 V6 F type OTS
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#8
Ian.
Just put the original reg back on the car after 5 years of Czech plates. Let's just say the fun has started!
Richard.
Glad you're enjoying the car. You deserve to after spending a tidy sum on it.
Just put the original reg back on the car after 5 years of Czech plates. Let's just say the fun has started!
Richard.
Glad you're enjoying the car. You deserve to after spending a tidy sum on it.
1971, S3, 2+2, manual. Red.
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#9
Hi.
Going through a very similar process myself. I've just rebuilt the carbs completely. Set them up on the bench and expected a few tweaks would have the car running great. Not quite that simple, as it turns out!
Carbs completely rebuilt using the zenith kit, along with new jets and manual spec needles (car used to be an auto).
Replaced ALL hoses that connect to the manifolds/ carbs with brand new items.
New air filters, fuel filter, etc. The car also has a DAB 113HE kit from SNG barratt. It has a new set of leads and I changed the plugs a couple of months ago.
It starts poorly, runs if idle is kept high (1200 rpm+). I can balance the carbs using my synchrometer and all the linkages appear to be opening the throttles at the same time. When driving it sounds like it's missing some cylinders. Have checked and double checked leads (and a few times more), including fully removing and replacing one by one.
My biggest problem seems to be timing. I can not find a set of timing marks. I seem to have the same problem that one of the chaps (Craig) has on this thread http://www.jcna.com/forums/view.php?Vre ... Vthread=51 where he has no timing marks on the damper. Not sure if that thread is conclusive on this matter, but I have no timing mark indicatorhttp://www.sngbarratt.com/ProductDetail ... 9416182612 either.
This makes it just a tad more difficult than usual to set the timimg! I could follow the instructions for the static set up at the bottom of the JCNA thread but TDC is a bit tricky to find with the engine in the car and not being allowed to rotate it backwards...
Has anybody else experienced this and if so what did you do to address it? Any advice welcome!
Thanks,
Calum
Going through a very similar process myself. I've just rebuilt the carbs completely. Set them up on the bench and expected a few tweaks would have the car running great. Not quite that simple, as it turns out!
Carbs completely rebuilt using the zenith kit, along with new jets and manual spec needles (car used to be an auto).
Replaced ALL hoses that connect to the manifolds/ carbs with brand new items.
New air filters, fuel filter, etc. The car also has a DAB 113HE kit from SNG barratt. It has a new set of leads and I changed the plugs a couple of months ago.
It starts poorly, runs if idle is kept high (1200 rpm+). I can balance the carbs using my synchrometer and all the linkages appear to be opening the throttles at the same time. When driving it sounds like it's missing some cylinders. Have checked and double checked leads (and a few times more), including fully removing and replacing one by one.
My biggest problem seems to be timing. I can not find a set of timing marks. I seem to have the same problem that one of the chaps (Craig) has on this thread http://www.jcna.com/forums/view.php?Vre ... Vthread=51 where he has no timing marks on the damper. Not sure if that thread is conclusive on this matter, but I have no timing mark indicatorhttp://www.sngbarratt.com/ProductDetail ... 9416182612 either.
This makes it just a tad more difficult than usual to set the timimg! I could follow the instructions for the static set up at the bottom of the JCNA thread but TDC is a bit tricky to find with the engine in the car and not being allowed to rotate it backwards...
Has anybody else experienced this and if so what did you do to address it? Any advice welcome!
Thanks,
Calum
1973 Series 3 2+2. UK car that was converted to LHD. Now back in UK as of Nov 2013.
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#10
I had a crawl around and took some pictures all around the crank pulley.
http://1drv.ms/1pxZwfb
Seems that the engine number matches the plate at least! The car is unrestored and I don't think the engine has ever been out.
Thanks!
Calum
http://1drv.ms/1pxZwfb
Seems that the engine number matches the plate at least! The car is unrestored and I don't think the engine has ever been out.
Thanks!
Calum
1973 Series 3 2+2. UK car that was converted to LHD. Now back in UK as of Nov 2013.
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