It has to be electrical, right?

[jeremybarnes]

Nearing wits end, hope someone can help... Have posted the same thread on J-L this morning, while sitting on the side of the road, in the hope of ideas.

1967 E-type, 4.2l, coupe. Car wouldn't start about a month ago, after replacing all ignition parts. Checked and double-checked everything, nothing was amiss. Finally pulled all the ignition pieces apart again and put it back together, and she started perfectly. Drove 50+ miles last weekend without any issue, including multiple hot-starts to ensure everything was good.

Started the car this morning, choke on and a quick bump on the starter, and it was perfect. Drive about three miles when it backfired loudly through the carbs and died. On the side of the road, waiting for a tow truck as I type this...

I have just checked: cap is tight on the car. Cap is clean and rotor shows that it's been contacting the cap. All wires are tight. Pulled the coil wire out the cap and it makes a fat spark when grounded to the head. Checked, and there is a spark when you pull the points apart. Gap still .018. Pulled the fuel line off the rear carb and it gushes fuel with the pump on, so that system is good.

Car turns over cleanly on the starter, so plenty of cranking power. One out of five or so start attempts, it will sort of catch but dies in seconds -- when this happens, the engine shakes and coughs; the rest of the time it just cranks without firing.

I know it's electrical, it has to be because it's intermittent, but I'm at a loss... And I'm sure it'll turn out to be something simple too. Help!!

To recap: Stock ignition system. I've replaced the plugs, used two different caps and wire sets, two different condenser and points sets. Points set to .018, timing set dynamically to 9 degrees. Ran perfectly last weekend, and again this AM. Now no start.

Any ideas what to try next?

Thanks all,
Jeremy

[mgcjag]

Hi Jeremy......sounds like intermitant electric........check out the live feed through the ignition switch..and fuse block to coil....you will need a test lamp/meter and move all the contacts to check for bad connection

[jeremybarnes]

Not sure I follow what you're saying, Steve. The "live feed"? When I drop the center panel down, all wires on the switch appear to be tight and connected properly. Can you elaborate on what I should be looking for?

Thanks for the idea.

Jeremy.

[ralphr1780]

Jeremy, did you check the dizzy is well positioned? It could have rotated if incorrectly/insufficiently tightened and hence wrong timing.
The rotor can also be of poor quality and causing loss or poor spark.

[jeremybarnes]

Thanks Ralph. Just went and checked, dizzy is rock-solid and tight, hasn't moved at all. Thought about the rotor, so put the old one back in as a tester, no change at all...

Jeremy.

[mgcjag]

Hi Jeremy....the live to the coil comes via the igniton switch, rev counter, fuse panel connection etc, could be an intermittant bad connection anywhere

[Hugo]

[quote="jeremybarnes"]Nearing wits end, hope someone can help... Have posted the same thread on J-L this morning, while sitting on the side of the road, in the hope of ideas.

I have just checked: cap is tight on the car. Cap is clean and rotor shows that it's been contacting the cap. All wires are tight. Pulled the coil wire out the cap and it makes a fat spark when grounded to the head. Checked, and there is a spark when you pull the points apart. Gap still .018. "

Rotor arm? There are a lot of cheap Chinese rotor arms about these days that will earth down to the distributor centre post. You may have a spark coming out of the coil, but is it going to the plug leads? Incidentally, the rotor arm shouldn't contact the terminals in the cap - it just has to get somewhere near them. Like wise HT wires don't have to be tight - it might actually be better if they're loose.
Can't remember if I posted this before, but one dodge in the old days with motorbikes was to chop the HT lead in half & wind each end (either side of the break) around opposite holes in a plastic button. This means the spark has to jump a gap before it can get to the spark plug, thus ensuring that you have a good fat spark rather than a feeble one which can just dribble across an oiled-up plug.

[Hugo]

And it's no good just laying a plug on the head & seeing if you get a spark - it may jump a plug gap at atmospheric pressure, but that is n guarantee it will jump the same gap under compression. Get the wife to hold one of the plug leads 3/8" or 1/2" away from the head while you crank it. If she jumps it's a promising sign ;)

[cactusman]

I would be suspecting the rotor arm. Get a red one from the distributor doctor...

[paulsco]

Hi Jeremy,

I see no mention of the coil being replaced; I know you said there is a good spark, but coil problems tend to be intermittent.
Have you tried another coil?

Paul

[abowie]

If you are using the repro Champion plug caps these are known to fail and will do exactly what you describe.
Check the resistance of the caps; they should be under 5k ohm.

Also see http://www.projectetype.com/index.php/t ... spark.html

[mark10337]

Check also that the rotor arm is actually turning, not has been turning from the evidence on the cap.
I've had an issue before where all the electrics were new, replaced, and working but it was misfiring and sometimes a real pig to start. Found that the advance weights would sometimes get stuck. Distributor needed a good clean.

[jeremybarnes]

Thanks all. Here's where I am:
- followed Andrew's check-list, and, strangely, it all checks out
- I was using the champion plug ends, but swapped to a push-on wire now
- making gross adjustments to the timing by turning the dizzy makes little difference it seems
- pulled the caps to the carb bowls and they're equal in float level
- starting fluid didn't help
- when it does sort-of start, the engine shakes and coughs just like its only running on two or three cylinders
- when it stalls after 5 seconds or so, a small puff of smoke smoke comes out of the one of the carb intakes, suggesting timing again

Still digging around...

Jeremy

[JagWaugh]

...
Get the wife to hold one of the plug leads 3/8" or 1/2" away from the head while you crank it. If she jumps it's a promising sign ;)

You'll want to pre-order one of these before trying the HV excitation on your partner:

[chrisfell]

Check the cam timing. Very rarely this happens, but the venier in the cam sprocket can crack allowing the cam to rotate within its sprocket. Symptoms are as you describe. Simple to check with the cam cover off.

[christopher storey]

Rotor arm is the most likely culprit. As a temporary expedient, try interposing some cling film between rotor arm and distributor shaft . If that doesn't make any difference I would also try a coil substitution as a temporary measure

[andrewh]

Did you check the inside of the distributor cap for any electrical tracking marks? It certainly sounds to me that its a ignition short somewhere. Could be coming from a small crack in the distributor cap which manifests itself when hot and/or carbon tracking. Maybe worth trying a different Cap. I love and hate these sort of problems in equal measure as they can be so many different things and notoriously hard to pin point but satisfying when resolved. I have had similar over the years on lots of different cars and have found it to be; incorrectly fitted points with insulating washers on the feed not in the correct order, broken low tension lead shorting to the body of the distributor , rubbish rotor arms, cracked caps and faulty condensers just to name a few. Good luck.

[Moeregaard]

Check all of the aforementioned items Andrew mentions, then have a look under the car to see if the ground strap is intact. A flaky ground can send you on a seriously wild goose chase. Regarding a tracked distributor cap, toss the cap in the dishwasher when the wife isn't looking. This often works.

[christopher storey]

C Regarding a tracked distributor cap, toss the cap in the dishwasher when the wife isn't looking. This often works.

That's a good idea. It leads to this thread

"E Type causes marriage break up "

[jeremybarnes]

Interesting development... it now seems that fuel only gets to the engine if a line is cracked or the filter bowl is loosened. Bear with me.

I *knew* from loosening a fuel line at the carb, and because all the carb bowls have fuel in them, that the pump was working fine. Or was it...? It was suggested that the issue might be the fuel pump, so I emptied the filter bowl and turned the ignition on to see if it would refill. The pump ticked loudly for a couple of seconds and then stopped, as if the bowl was full and there was pressure. However, the bowl only filled to 3/4 full and that's when the pump shut off. Did it again, and had the same result.

So, what causes this? I have a vented fuel cap (and have tried with the cap off completely), have done this experiment without a filter in the bowl at all, and it would seem this may be my problem all along, rather than an electrical issue.

So: dead pump? Surely the system isn't supposed to have a vent in it somewhere that is now blocked? Other thoughts? Any reason it would fill part-way, but not more?

Ugh...

Jeremy