Jumping and spitting under acceleration
#21 Re: Jumping and spitting under acceleration
Great stuff Philip
I figured that getting to the timing ref. plate would be a challenge!
At east I know what to do now, so thanks.
Hopefully get some time this weekend to level things off - and even more hopefully, drive around in a super smooth V12!
Will keep you posted.
Have a good (Bank Holiday) weekend everyone
I figured that getting to the timing ref. plate would be a challenge!
At east I know what to do now, so thanks.
Hopefully get some time this weekend to level things off - and even more hopefully, drive around in a super smooth V12!
Will keep you posted.
Have a good (Bank Holiday) weekend everyone
Hilton - V12 2+2
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#22 Re: Jumping and spitting under acceleration
Just for the sake of more consternation and mayhem...
My car is idling (smoothly) at:
19deg BTC - without vacuum attached to vacuum advance.
30deg BTC - with vacuum advance attached. (Its notable that only 11 degrees advance is added - another argument in favour of not needing ported vacuum )
My timing light is an EQUUS model 591 538 with buttons to change the strobe to align the pulley TDC mark with the "0" mark on the timing plate and then read the timing value. Setting the timing light to 0 gives the same readings on the car's timing plate. A measuring error is thus rather unlikely.
My car is idling (smoothly) at:
19deg BTC - without vacuum attached to vacuum advance.
30deg BTC - with vacuum advance attached. (Its notable that only 11 degrees advance is added - another argument in favour of not needing ported vacuum )
- When I remove vacuum, idle speed drops. Would anyone care to offer an explanation why?
- When I re-attach vacuum, idle speed picks up again.
- When I suck VERY hard on the pipe to the vacuum advance, I can make the engine idle higher than when vacuum is attached. Would anyone care to offer an explanation why?
My timing light is an EQUUS model 591 538 with buttons to change the strobe to align the pulley TDC mark with the "0" mark on the timing plate and then read the timing value. Setting the timing light to 0 gives the same readings on the car's timing plate. A measuring error is thus rather unlikely.
Best Regards
Philip
Jag: 72 S3 XKE, 74 S3 XKE OTS, 80 XJS (Megasquirt + 5sp manual O/D)
Jensen: 74 Interceptor (EFI by Megasquirt + O/D 4sp auto)
Chev: 59 Apache std, 70 C10 (350V8, 700R4)
Philip
Jag: 72 S3 XKE, 74 S3 XKE OTS, 80 XJS (Megasquirt + 5sp manual O/D)
Jensen: 74 Interceptor (EFI by Megasquirt + O/D 4sp auto)
Chev: 59 Apache std, 70 C10 (350V8, 700R4)
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#23 Re: Jumping and spitting under acceleration
Hi Guys
+1 to Philips timing post.(apart from the porting discussion)
Use 12deg Before TDC at idle with the vacuum disconnected, and plugged .
You need a good timing light to achieve this. You will also probably have to clean up the marker plate and perhaps remark the degrees with a white marker pen.
I agree with respect to the distributor retard module. Just leave this disconnected and plug both the module and the carb entry, which should be under the left rear carb looking from the drivers seat. Your car will love it.
By the way I run 95 octane with no problems, as 98 is hard to get reliably down here.
cheers
mark
+1 to Philips timing post.(apart from the porting discussion)
Use 12deg Before TDC at idle with the vacuum disconnected, and plugged .
You need a good timing light to achieve this. You will also probably have to clean up the marker plate and perhaps remark the degrees with a white marker pen.
I agree with respect to the distributor retard module. Just leave this disconnected and plug both the module and the carb entry, which should be under the left rear carb looking from the drivers seat. Your car will love it.
By the way I run 95 octane with no problems, as 98 is hard to get reliably down here.
cheers
mark
Mark Brown
1971 S3 Etype, now sold, sadly.
1971 S3 Etype, now sold, sadly.
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#24 Re: Jumping and spitting under acceleration
Do you have any reference for this chip Mark and a test schedule for the checking whether the existing is duff please? I have the SNG kit in my series One XJ12 , which is playing up and having asked and asked SNG for test information , resistances etc , I have not heard anything. I am keen to see whether mine is ok, or needs replacing and dont wish to buy the whole thing again. Thanks Andrew42south wrote: ↑Tue May 22, 2018 9:19 pmHi Hilton
The Amp mounts in the valley where the original was. Don't worry about this as the internals of the amp are now a GM solid state chip, not the original style circuit board with its heat sensitive components. So the comments about moving the amp to the front of the engine for extra cooling dont apply to this amp.
Heaven forbid that you should ever have another amp problem, but the internal chip is available on the internet for around $25USD.
Cheers
Mark
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#25 Re: Jumping and spitting under acceleration
Hi Andrew
If you google search for AC delco D1906 you will find several sources. The amazon ad has a picture.
As far as testing goes Perhaps the testing listed for the later cars with the CEI amp will be suitable. It is the same system.
As you can see it is possible to open the amp from the bottom. I have seen reference to a zenier diode in there which should be replaced as well.
Im afraid I have very limited electronics knowledge, so hopefully someone with more knowledge will answer.
Cheers
Mark
P.S. I just checked Kirbys book and there is quite a bit of info on the HEI ignition module in there.
If you google search for AC delco D1906 you will find several sources. The amazon ad has a picture.
As far as testing goes Perhaps the testing listed for the later cars with the CEI amp will be suitable. It is the same system.
As you can see it is possible to open the amp from the bottom. I have seen reference to a zenier diode in there which should be replaced as well.
Im afraid I have very limited electronics knowledge, so hopefully someone with more knowledge will answer.
Cheers
Mark
P.S. I just checked Kirbys book and there is quite a bit of info on the HEI ignition module in there.
Mark Brown
1971 S3 Etype, now sold, sadly.
1971 S3 Etype, now sold, sadly.
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#26 Re: Jumping and spitting under acceleration
Haven't had much time to time the motor yet due to family crisis but had a few minutes last night to stick my head under the front......
Now this is a bit embarrassing, but couldn't find the timing adjuster plate!
Admittedly, didn't look too hard, but could anyone help a blind old fart please?!
Cheers :)
Now this is a bit embarrassing, but couldn't find the timing adjuster plate!
Admittedly, didn't look too hard, but could anyone help a blind old fart please?!
Cheers :)
Hilton - V12 2+2
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#27 Re: Jumping and spitting under acceleration
Its the black metal plate immediately below the crank damper. Hard to see on the car.
Best Regards
Philip
Jag: 72 S3 XKE, 74 S3 XKE OTS, 80 XJS (Megasquirt + 5sp manual O/D)
Jensen: 74 Interceptor (EFI by Megasquirt + O/D 4sp auto)
Chev: 59 Apache std, 70 C10 (350V8, 700R4)
Philip
Jag: 72 S3 XKE, 74 S3 XKE OTS, 80 XJS (Megasquirt + 5sp manual O/D)
Jensen: 74 Interceptor (EFI by Megasquirt + O/D 4sp auto)
Chev: 59 Apache std, 70 C10 (350V8, 700R4)
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#28 Re: Jumping and spitting under acceleration
Thanks Philip - that's very helpful
Must've been so close I couldn't see it!!
Hilton - V12 2+2
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#29 Re: Jumping and spitting under acceleration
Yes, its quite a challenge to shine the timing light on it AND see what the result is. The large lower coolant pipe is somewhat in the way.
Best Regards
Philip
Jag: 72 S3 XKE, 74 S3 XKE OTS, 80 XJS (Megasquirt + 5sp manual O/D)
Jensen: 74 Interceptor (EFI by Megasquirt + O/D 4sp auto)
Chev: 59 Apache std, 70 C10 (350V8, 700R4)
Philip
Jag: 72 S3 XKE, 74 S3 XKE OTS, 80 XJS (Megasquirt + 5sp manual O/D)
Jensen: 74 Interceptor (EFI by Megasquirt + O/D 4sp auto)
Chev: 59 Apache std, 70 C10 (350V8, 700R4)
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#30 Re: Jumping and spitting under acceleration
If you can get hold of a spare timing plate from an XJS (or similar v12) then a sensible thing to do would be to set the engine to TDC on cylinder 1A one last time at the old timing plate and then fix a new plate to somewhere visible and paint a new line on the crank pulley against the zero mark.
I have mine just the the right side of the car under the water pump.
kind regards
Marek
I have mine just the the right side of the car under the water pump.
kind regards
Marek
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#31 Re: Jumping and spitting under acceleration
Hi guys
When it comes to shining the timing light on the degree plate I found the best way was to get one of the timing lights with the adjustable tilt head, and a small screen to read the numbers from.
It allows you to poke the head up between the hose and the degree plate whilst still being able to read the screen or see the light on the degree plate.
Check out eBay, they are reasonably priced.
Or just follow Marek’s advice.
Cheers
When it comes to shining the timing light on the degree plate I found the best way was to get one of the timing lights with the adjustable tilt head, and a small screen to read the numbers from.
It allows you to poke the head up between the hose and the degree plate whilst still being able to read the screen or see the light on the degree plate.
Check out eBay, they are reasonably priced.
Or just follow Marek’s advice.
Cheers
Mark Brown
1971 S3 Etype, now sold, sadly.
1971 S3 Etype, now sold, sadly.
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#32 Re: Jumping and spitting under acceleration
Well, here’s an update fellas:
I’ve got the timing pretty near and the answer to the thread title’s problem is in one word: Ignition.
The car now starts, runs, idles and accelerates as smoothly as you like. So if anyone with a standard OPUS ignition system asks the same question, I’d just point them in the direction of the SNG Barrett ignition upgrade for £468 (also available from M & C Wilkinson of course!)
I did have a split in a carb diaphragm but even when this was replaced, it made only a marginal difference as I believe the old ignition was about to let go anyway as it seemed to be getting worse every time I took the car out.
So in summary,
The car now runs better that it ever has done in the 8 years I’ve owned it. Smoother and more responsive and so far at least, none of the hot start issues that were plaguing it.
Thanks for all the advice guys - you’ve helped me enjoy my car again. I owe you all a drink
I’ve got the timing pretty near and the answer to the thread title’s problem is in one word: Ignition.
The car now starts, runs, idles and accelerates as smoothly as you like. So if anyone with a standard OPUS ignition system asks the same question, I’d just point them in the direction of the SNG Barrett ignition upgrade for £468 (also available from M & C Wilkinson of course!)
I did have a split in a carb diaphragm but even when this was replaced, it made only a marginal difference as I believe the old ignition was about to let go anyway as it seemed to be getting worse every time I took the car out.
So in summary,
The car now runs better that it ever has done in the 8 years I’ve owned it. Smoother and more responsive and so far at least, none of the hot start issues that were plaguing it.
Thanks for all the advice guys - you’ve helped me enjoy my car again. I owe you all a drink
Hilton - V12 2+2
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#33 Re: Jumping and spitting under acceleration
Best Regards
Philip
Jag: 72 S3 XKE, 74 S3 XKE OTS, 80 XJS (Megasquirt + 5sp manual O/D)
Jensen: 74 Interceptor (EFI by Megasquirt + O/D 4sp auto)
Chev: 59 Apache std, 70 C10 (350V8, 700R4)
Philip
Jag: 72 S3 XKE, 74 S3 XKE OTS, 80 XJS (Megasquirt + 5sp manual O/D)
Jensen: 74 Interceptor (EFI by Megasquirt + O/D 4sp auto)
Chev: 59 Apache std, 70 C10 (350V8, 700R4)
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