Went to start the car the other day and it simply wouldn't start. Was running it the day prior, and has never failed to start.

However, the day prior it almost didn't start, but with some flooring of the gas it eventually fired and started after trying to turn it for awhile with starter (slow eventual start). Then we drive around town with no issue, and it started after the next stop when we went to come back home.

So I'm suspecting a possible fuel supply issue (gas is fresh and high quality).

Now it won't even fire and show signs of possible starting. It just turns the engine.

I have spark at plugs.
Removed air canister to ensure no air restrictions.
The distrubutor seems solid so firing angle shouldn't be off. And because it started after the first issue, I'm suspecting something was building towards failure, rather than a sudden break or change.

Are these signs of a fuel pressure or supply problem?
What's the best way for me to determine sufficient fuel pressure to the carbs?
I opened the two carbs and there was full fuel under the floats.
Is there a way to know if the fuel is actually reaching my cylinders?
Is there a quick test to get fuel into the cylinders and verify spark timing?

Trying to get this up and running again for an upcoming engagement, and to enjoy while weather is still fitting.

Any help or ideas to try would be truly appreciated...

Jerry.

 

Well it's all up to you?
How deep can you troubleshoot this?

You have checked for spark but is it happening at the correct time?
Do you have a timing light?
One suggestion for the future is ALL old stuff I work on gets a breaker less ignition conversion if there is one made for it. Really helps with starting.

Have you checked for fuel?
If you don't have a fuel pressure gauge you can unhook the fuel line to the carburetor and crank the engine. Now my MK2 has an electric fuel pump so it might be as easy as just turning the key on?

What type of fuel pump do you have? I would think a 1968 model would have the electric pump? Can you hear it running?

From your description I guess the engine is turning over but not starting?

One quick test I always do is spray a bit of starting fluid in the air cleaner. Does the engine kick off now?

Sure sign of a fuel problem but be aware it can mean you are flooding the car as well as not getting enough fuel.
.
.
.

 

Also check the choke, if the plugs are soaking wet then you are flooding the engine, if they are dry as a bone after some cranking then probably little/no fuel.

Sometimes holding your hand over the air intake to each carb while cranking will cause a large vacuum which can suck the petrol through if there is some crud in the jets, timing should not have gone off unless you have a really loose timing chain.

Fuel is the most likely scenario.

 

Firstly... THANKS SO MUCH for the quick replies!!!

It's my first time on thIs forum as the car is a recent acquisition.

I don't have a timing Gun but can get one... figured it would be the last thing I try as the chain jump isn't the most likely but plausible for sure. Was looking to try the simpler checks before I ratchet it up more.

I do have electronic points on order for exactly the reason you mention, but will likely reach out to pubfolks again as that distributor seems shoe horned under the intake manifold....

It does have an electric pump which you can hear build when the key is turned. It isn't the original but has worked for the prior owner for the last four years... I understand there's a filter near it as well, and if there's a pressure problem it be going there. You mentioned simply removing the line at the carb... am I expecting a jet, or lower pressure? With a float carb I suspect the vacuum is driving the consumption, rather than the pump pushing it in. But I will regardless disconnect and check.

When I removed the plugs they didn't look wet after trying to start, but I may need to try to turn it more... should they be obviously wet as soon as I turn it over and remove them?

I will also try the suggestion about covering the carb intakes.

Yes the engine is turning over but not any sign of firing (not even a hint of combustion that would give me hope).

On spraying directly into the intake, I did this... I use a Quick Start product which has resolved every spring startup issue I've ever had with mowers or other engines, sonitjstried and true, and still it didn't fire... so I thought perhaps it was a spark issue. But perhaps I hadn't sprayed it properly... one can spraying down into the open Carb (with piston removed)... other carb not opened up at all, so fuel. And this might have been tried after flooding it.

Would vacuum lines or lack of vacuum prevent me from getting a "firing" - I have no reason to suspect a vacuum issue, but it entered my mind as something to ask about.

So.... I will:
Try the hand over carb intake method to see if I get fuel ducking in...
Take the fuel line off to check for some sign of strong flow
After trying to turn it over, will check plugs for wetness

Does pouring a bit of fuel into a couple plug holes and inserting the plugs act as a way to see if spark is there, or any value at all?

 

replace the fuel pump.

 

This is getting too complicated.
The fact that you can drive it around town indicates that it's getting fuel, ignition and the ignition timing is correct.
If the problem is only happening with a cold engine, then it's either not getting enough choke or too much _ flooded engine _ you would smell fuel in this case.

And you have a 68 240, do you have SU carbs or Solex ???

I think T John is heading in the right direction.
Either too much choke or not enough.

 

I was able to drive it around town until it wouldn't start anymore.
SU Carbs.
I can smell fuel, or could.
I emptied the glass bowl and cleaned it out. It was filled up slowly when I turned on the key (electric pump).
I've tried starting it at both ends of the choke with no difference. It always started instantly without issue, until when it recently decided not to.
Except for maybe the last day where it did seem to be trying to fire while turning, but never enough to run.... then, assuming it was flooded (smelled gas), let it sit overnight, and it has never since fired. It only turns.

I checked oil to ensure there wasn't any fuel in it from flooding past the rings in the event of subsequent floods, but oil is just oil.

 

Have you removed a plug and laid it on the engine to see if you are getting a spark when you try to start the engine? When you turn the engine over are you getting a regular sound or is it irrregular?
I have just purchased a 'S' type that was running, as the owner was decelerating to a stop he watched the tachometer continue to drop as he stopped he realised the engine had also stopped. Turns out the top chain eccentric had become loose and allowed the cam timing to slip-bent valves!

 

Assuming you still have points, check those first (replace just to eliminate that) _ condenser too.
Substitute with a known working coil.

99% of stuff like this is usually ignition.

Do the simple things first before assuming more series things like valve timing.
Remember that Jags have a very over-kill valve train, so it's highly likely that it's the problem.
A simple compression test would rule that out.

Carbs are simple, they don't usually go wrong, you've checked the float bowls so it's getting gas.

You can check for sticky pistons, but that normally wouldn't' cause it to suddenly not start.

An unpredictable ignition could can show spark if tested, but under any kind of load, they can fail.

Also check the braided wire inside the distributor to make sure it's not grounding out.
Make sure it's not frayed through too.

Also remove the distributor cap and make a serious attempt to turn the rotor _ it should not turn. If it does turn the drive gear, roll pin and or key are having issues.
There should be some play to it from centrifugal advance.

Make sure you're actually getting 12 volts to the coil.
What make of coil do you have, is it a 12 volt coil or one that requires a ballast resistor ?

 

Quick check - you will need a friend

whilst cranking and pedal half down, squirt some quick start into both carbs, if it starts and runs, warm up and then turn it off, if it re-starts then choke problem probably. If it doesn't start or fire at all then spark, if it fires and dies then fuel issue in carb.

Reading the above, Jeff looks like he's on the trail, I would be looking at coil, a weak spark would cause cold start issue, and when a coil is old, it often breaks down when it gets hot resulting in a dead engine.

Good luck.

 

Spark test as described: yes
Regular sound, no deviations (as in partial firing), therefore no firing.
The last drive came right home without an issue or symptom of firing issues (that we pick up on). The next attempt to start it was rough with some attempts to fire (so it was trying), but didn't quite get there or stay running. Then it ultimately just won't fire now. Still parked where it was the last drive.

I just posted a couple nights ago, and work long hours so i need to still try a couple great tips from the guys in this forum. Hoping to do that this weekend.

This dialogue is helping me get some hope and to line up what I need to try these tests and possible solutions (or at least get closer to the cause).

 

This is really good!
I do have 12v (positive gnd), and it has a Mopar coil in it which I suspect is not the original, but it's not new and has worked for some time (but perhaps not ideally and I'm not ruling out it may be wrong or need a ballast). Looks like the original however. I measured the primary to be 1.8 ohms... which seemed inconsistent with internet references to being under 1 ohm with a resistor, or over 3 without. I could not find what the original coil resistance was supposed to be or if it had a resistor. I don't see a resistor near this, but not sure where they would have placed it anyway (some guidance here may help me). So, I went to get a replacement for this Mopar coil to eliminate it (the number was all still clear), and both cross referenced coils looked the same and each stated a ballast resistor was needed. Only one had the center high voltage (pressure) male connection that looked like mine, so I measured the primary coil resistance... 1.8 ohms (same as mine). So I assumed mine must still be good and didn't buy it. Mine has been running as is without issue in the past so either I don't know where the ballast resistor is, or it's at the cusp of not needing one. But based on your comments that getting a spark isn't a guarantee it fires under load, I will replace it this weekend considering the low cost. But I'd like to know what the primary coil resistance is in the original, if I should get the same coil I have, and if I need a resistor. When I look for local C30120 coils for cross reference, they can't find it. So I had to use the proven Mopar as my base. Any advice here on primary resistance, resistor location and sizing, or a replacement I could get from Amazon.com or eBay.com would be great. I'd rather not replace the Mopar with an equivalent if it isn't ideal.

Now on the distributor... firstly, how do I get at it?!!!! I see all the new cables coming from it, and the high voltage lead going in there, but the cap itself seems inaccessibly tucked under the intake manifold. I've worked with distributors before, but I could always see fairly well directly into it. Do I need to remove the intake manifold for this work? I can't even see where the high pressure feed connects at the center, so I fear starting such a job only by feel, when I really will need to see the innards when I open it... I'll need this advice anyway when my electronic points kit comes in. I'm totally in agreement with you on eliminating the simple stuff first, and don't even have a problem replacing contacts kit and condenser now to be safe, if I can access them, and get a replacement locally (will my locally unusual positive ground system require a different condenser?). I know my positive ground electronic contacts had to come from Britain and just shipped so they'll be a couple weeks.

AGAIN... I thank you in advance for your time and patience... we're having great weather so this is killing me to see her parked there...

 

I will be doing these tests you mention this weekend so thank you. When I sprayed the Quck Start into the one open carb while my don turned it over, I got nothing, which is why I went into the spark mindset and the coil work I replied to John with. So I'll be going back to that with further replies on my coil questions and advisement on dustrubutor cap access.

 

Just reread your note... I did not have the pedal pressed down when I did this but believe the choke had the butterfly valve open.

Also, I meant the post from a Jeff (I cited a John). But thank you both.

I'm looking forward to trying this work on the weekend and will report back. I only now need tips from you guys on the distributor cap access, and my questions regarding the coil and resistor.

 

Gbourck
There's your problem, you're running a coil that's rated at 1.5 ohms in a car with an ignition system that's designed for a 3 ohm coil.

There's a Bosch ceramic 3 ohm coil that works well, it's epoxy filled so it can be mounted on its side so the oil doesn't run out.
Plus it can take the vibration from the engine being mounted just above the crank case breather.
This is a actually a bad spot to mount a coil because of the engine vibration and it's too hot. (right above the rad)
The S-Types had them mounted on the inner fender well closest to the distributor. (cooler spot)

Yes, it's a bear getting at the points, but it can be done. If you remove the breather for the brake servo, it makes it a little more accessible, but you have to be carful not to drop the tiny bits into the distributor.
Personally I don't even bother any more because it's such headache.
I place number one on compression at 6 degrees BTDC and slip the distributer out.
It's so much easier to grab my timing light and meter then it is to try and work on the distributor in-situ, but it's up to you.

You will have to replace the points and the condenser, they are probobly burned from too much current flow.

Be carful, there are lots of fake ones out there.


A quick explanation about coils.
At idle the points stay closed the longest, this is referred to as "dwell".
At slow speeds, the coil gets totally saturated with current and you get a good spark.
The problem with this is that because the points are staying closed at idle and at slow speeds too long, the coil can become too saturated (too much current flow).
This causes the coil to heat up beyond what it's designed for.
When this happens the insulation on the windings inside the coil break down prematurely and it shorts internally.
When the coil is cold things still can work OK, until it heats up.
That's why bench testing a coil with an ohm meter is a poor test.
Too much current flow can also causue the condenser to fail and you then get burned points.

To prevent this from happening they up the ohms resistance to 3 ohms to cut back on the current flow or the introduce a ballast resistor into the primary winding circuit.

Here's some reading on what too look for to get the right one.

http://www.ratwell.com/technical/BlueCoil.html

EDIT:
At the beginning of that article it talks about an internal resistor inside a 3 ohm coil.
This is wrong, a 3 ohm coils resistance is increased through more winding of copper wire.
This is also achieved by using a thinner gauge of wire.
A knock-off coil will have thinner gauge wire, it's cheaper to achieve the 3 ohm resistance then it is to add more windings.

 

I have been a while typing this and doing other things, in the meantime I see Jeff has posted, so this duplicates a lot of what he has said, sorry, I thought you had electronic ignition, if I am wrong ignore what I have said as Jeff has pretty well covered it above.


I will try and answer, there are 2 resistances you can measure, the primary which is what you are reading at approx 1.8 ohms, and the secondary (from HT outlet to coil +ve) this should be 7000 to 10000 ohms.
A normal non ballast coil for a distributor system would be normally 3.2 Ohms, and a coil for a ballast system 1.6 ohms.

However that is not the end of the story, when electronic ignition systems are used, they often specify high energy coils which fall into the 1.6 Ohm area (lower resistance, higher current, more output)

So before you change the coil, check what electronic ignition you have, and then check the coil spec that applies to that system.

As a test, if you take off the primary HT lead from the center of the distributor, on cranking this spark should jump approx 1/4" to ground, if the spark is weak, it could be down to 1/32"

A poor spark can be caused by a coil that is breaking down (can sometimes only breakdown when hot), on standard point systems, there is a capacitor that can go bad which is crucial to the spark, and on electronic ignition systems, the ignition amplifier which controls the spark can also be faulty. The ignition amplifier can be damaged if a coil of too low a resistance is fitted, as there is too much current draw through the amplifier, which is why the manufacturers normally specify what coil resistance to use.

If you check the spark first, if that is good then it is fuel or timing, if spark is good and it won't fire with quick start at all then I would suspect timing is off, you will need to take the cam covers off and check the valve timing, but I would be surprised if it was that with what you have described.

The distributor is not readily accessible, but you don't have to take off the inlet manifold to get to it, it's just awkward rather than impossible, you just need rubber arms and eyes on stalks, I have some in my tool box for just such occasions !!!

I hope this is of help

 

I assumed he has points, electronic ignition fails and that's it, but his didn't fail out right.
Points will limp along and then totally stop after a while for what ever that reason is that caused them to fail.

 

You are absolutely right Jeff , the OP said he had electronic points ON ORDER, I misread it, missed the "on order" bit. I guess he means contactless. So the contacts could well be burnt as you say, probably nearly closed and a weak spark as a result (he did say he had a spark) The 1.6 Ohm coil maybe OK with the new contactless points, but he will need to check spec with the suppliers.

One point re Electronic ignition, although 90% of the time they do fail outright as you say, there is a capacitor in the module that is switched in/out of circuit by semiconductors, if the capacitor starts to fail it can weaken the spark, this is not common, as the semi conductors usually go and then it's dead, not common, but also possible, so misfires and poor start can be electronic ignition too.

Addendum--

Just checked online, and Powerspark use a 3 ohm coil, but 123ignition use a 1.8 ohm coil, haven't looked at any others.

 

I had a Pertronix unit on my TR7 ages ago, the first one was DOA, the second unit worked for a few years then quit _ the tach was jumping all over the place, but it still ran. Couldn't trust it.

Had a Luminition unit on my Bentley and it just up and quit too, but it always had a week spark. Maybe had a bad capacitor in it from day one _ and very expensive.
Had to call a tow truck.

I'll never go back to these after market cheesy ignitions again.

 

Thanks to you both.

The primary was 1.8 on the e siting coil, in place for some time before my acquisition, and no resistor that I could see. The secondary came out between 10-11k ohms.

Just regular contacts in place still, installed about three years ago I'm told, when he had carbs rebuilt, tuned, and all plugs, wires, and contacts / condenser changed.

Spark I get off high tension gets 1/4 inch jump easily, and I get perhaps an 1/8+(going from memory now) going from the spark plug lead to the plug tip. But I'll need to recheck this. I did order the suggested Bosch epoxy coil from Amazon which will be here later next week (along with 6 new plugs). I got the "good one" based on the Ratwell article (thank you!), and seems to be the one with most ratings and very well rated by the customers... it's the Brazilian Bausch. I might simply start with that coil as I only want to change one thing at a time. But regardless, I'll get at replacing the contacts (replace even if the coil turns out to be the silver bullet.

The positive ground electronic ign kit ordered and now en route is:

K1pp & R4 - Powerspark Electronic Ignition Kit for Lucas 22D6 & 25D6 Distributor Distributor Positive Earth - Powerspark Ignition

It simply states "To be used with a coil resistance above 1.5 ohms only".
So I'm hoping that means the 3 ohm Bosch I now ordered is going to work still.

In the mean time I'm still wanting to validate the fuel supply situation and will play this weekend with that.

Stay tuned!!! (No pun intended)