My E-type dies after 15 minutes

Yesterday, was the third X in three drives (4 weeks) that my '67 4.2 has died while driving at slow/moderate speed (25-30 mph). Ambient T° was 95 or so. Humid, no rain (Houston). 15-25 minutes into drive and, with neither warning nor fanfare, stops running. Doesn’t sputter or run poorly, just quietly coasts to a stop. (You can feel a loss of power, as RPMs fall) Car was well warmed up and ALWAYS starts from cold on first turn of the key and runs like a bat. Once it’s dead, cranks but won’t fire, and no hint it once to start. 3 tows ain’t that much fun…and my wife is about to kill me. The car is new to me, having purchased it in April, and installing new points, rotor, and condenser.

The first time it was towed home, I replaced the coil, and also installed a new high voltage coil to distributor ignition wire, prior to which, I sprayed starter aeresol into the carbs and it didn’t make a difference. Problem seemed solved with a new coil (SNG Barratt/generic unmarked coil)…car started perfectly and then promptly died after 20 minutes of driving.

After getting home from the second disaster, and a cool engine, I could that the coil negative to distributor wire was off the coil’s negative male connector. Once connected, she fired up, first turn of the key, as usual. Home free, now…not so fast big boy…

Same story yesterday, car died but couldn’t be re-started, even w/starter fluid (can’t blame a boy for trying) Towed and arrived home about 2 hours later. Unloaded from tow truck, fired up on first turn of the key. Ditto this AM: started easily.

Tried this little experiment this AM: car idling in my garage, heated the coil with heat gun…it continued to run fine. The heat from the gun (about 10 minutes)…no effect,

I ordered a new Lucas Sports coil but am a bit gun-shy now. Your thoughts?
thanx steve

Sounds a bit like fuel starvation, although when my S11 XJ6 used to do it you could tell because the engine went onto 3 cylinders as one fuel bowl ran dry first. Was yours a sudden cut off as if the ignition was switched off?

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Try removing the filter element from the fuel filter. I had the same problem a few months back. I could drive about 5 miles, and then it would die. I found the filter was somehow clogged inside, even though it looked perfect. I removed it, and it drove just fine. Put in a new filter an no more problems.

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I think you first need to actually determine if it’s an ignition failure. I make it a habit to carry one of these:
image

They are about $4.00 at Harbor Freight but available at most auto stores.

I’ve also experienced failure in the brass fuel filter some of the cars came with. It’s a flat fine screen in the underside of the lid of the bowl, and can become clogged as Ray says.

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Problems like this require a systematic approach to trouble shooting. Replacing parts at random is rarely the answer. I know, I know, easier to say than do when you’re stranded by the side of a busy road in 100 degree temperatures…

Since you say that it has happened within 15 minutes on your last three drives I’d be inclined to pack a set of diagnostic tools and take the car for a drive around the neighborhood - hopefully on roads that will allow you to coast to the curb when it fails and safely fully diagnose the problem, or at least gather some good data points.

When it fails, the suddenness of the failure sounds more likely to be electrical than fuel related. I’d start by determining which electrical circuits are operational when it fails. You say it cranks, which rules out the battery and battery connections. Do the circuits that don’t go through the ignition switch still work - try turning on the lights to check? Do circuits that go through the ignition switch work - try the direction indicators, for example. If not, try wiggling the ignition key in the lock. Switch failure is quite common on the 4.2 Series 1s. I just had to replace the switch on my '66 S1 which exhibited the same symptoms as you are describing. The key would get hot and after 15 minutes or so of driving the engine would cut out. I could keep it running by wiggling the key and pushing it in a particular direction in the lock. When it was cold there was no problem.

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I’m not reading a sudden failure but a gradual loss of power, which to my mind is fuel starvation - specifically caused by a dirty fuel filter (per Ray). If you have a supplemental in-line fuel filter canister I suggest you change it out, along with the usual element in the glass bowl.

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When my filter clogged up it was still driveable for a bit and only ran smooth while I floored the pedal.
So it loses power gradually yet doesn’t get rough and is not like killing the ignition?

Also if it was fuel it would start on ether. It’s got to be something not fuel related.

If the coil change fixed it for a while it means the new coil didn’t last and you should test the next one around the neighborhood. You don’t have a ballast for the coil right - did you get a 12V coil?

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The engine would fire on ether but it won’t start and run without fuel.

Sounds like we need more details.

What do the sparkplugs look like after the engine dies and fails to restart? If it’s electrical they should be wet.

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If you tried starter fluid and it would not fire, I think it is an ignition problem - not fuel.

I would suggest you try eliminate the possibility that a wire is flexing, (ie with a broken core) and thus becoming intermittent within the wire or at the crimped on terminal connection.

This is what I would do if it was my car

  1. I would temporarily replace the wire between the coil and the distributor with a wire and see if the problem goes away. If problem does not go away, then connect back old wires and go to 2)

  2. Run a wire from the output of the tach, to the coil (after unplugging existing input wire at coil) to check if that wire has a problem. If problem does not go away, reconnect wire just unplugged in test and then go to 3)

  3. Run a wire from unswitched side of fuse box (or from the battery) to a manual on/off switch in your car that you leave on the passenger seat. Put a 10 amp fuse in the line close to the source (ie the battery or the unswitched side of fuse box.) Unplug the input wire at the coil that comes from the tach and tape the end so it cannot short on anything.

From the manual on/off switch on passenger seat, run a wire to the input of the coil. Only turn on this passenger seat on/off switch when car Ignition is on. See if problem goes away. If not reconnect disconnected wires and go to 4) Note that engine will continue to run if you leave this passenger seat switch on and then turn off ignition switch so I repeat you should only turn on this switch when ignition is on and be sure to turn it off when you turn off ignition

  1. If you reach this far, I think the problem is inside your distributor and we can get to that later if your car passes all the above tests

Dennis
69 OTS

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Steve I am also in Houston. I live in the Heights close to downtown. I have not had mine die while driving but I have battled through some no start situations after driving for awhile on hot days over the last 20 years. I don’t claim to be the best mechanic but so far have managed to solve my various problems without taking it to a shop. If you want to try to meet sometime I am happy to take a look and try to help in person. One thing I do have that might help is a Colortune. It is a glass top spark plug so you can see the flame and spark in a cylinder. If we could get the problem to repeat it should be easy to at least determine if fuel or spark or a combination of issues.

David
68 E-type FHC

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Won’t start on starting fluid certainly points to electrical as the cause. Ignition switch getting hot? Coil would have been my first guess, but that usually starts with erratic running before total breakdown. A condensor on the other hand…

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I once received a bad out of the box condenser. After 15 minutes it started backfiring and stalled. After cooling off for an hour it ran great again. If you have a known good and stable one it’s worth the 15 minutes to swap and test it.

I also once had a fuel pump that would start start delivering inadequate pressure, especially under heavy load.

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When these kind of problems show up, I always had for the condenser first.

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I had a 68 Fiat 124 sport Spider. During the restoration I decided it needed a sport coil. Ok, bought the coil, installed it. Car ran great for maybe 30 minutes. Then would just die. Tow it home and it started just fine. Lather-rinse repeat. One time when it died I opened the hood and inadvertently touched the coil; ouch - burning hot. I put the old, flaking paint dented coil back on and the problem never returned.

About 2 years later the car started sputtering and dying after 20-30 minutes. It would sit for a while and then start right up, only to repeat the process. Rust in the gas tank, enough that when the engine was running the suction from the mechanical pump would draw rust particles against the filter enough to block the flow of fuel. Shut it off and the enough of the particles fell away that fuel could flow again until the next build of particles. I cleaned and coated with gas tank with a product I bought from J. C. Whitney.

I’ve only experienced one dead condenser and it was like an on-off switch and once it died it wouldn’t resurrect itself.

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Drive it again until it dies. Then, confirm that you have no spark. If so, follow this.

No spark.

Symptom: car won’t start or run at all.

NOTE: assumes NEGATIVE earth, points in distributor.

To Confirm: Put a plug tester in series with a plug. It should flash when engine is cranked. If no flash check other plug leads as well. No flash = no spark.

If you do have a flash the problem is NOT spark per se, although it MAY be plugs. See 9.
Otherwise the problem may be timing, or fuel or compression. These steps will not help those things.

Take each step one at a time, in order. At the end of each step try to start the car.

  1. Battery flat.
    If the car cranks over it is almost certainly OK.

  2. Engine earth.
    Spark requires a good earth to the negative terminal of the battery. Check that the engine is earthed with an ohmmeter or voltmeter between the battery and the block.
    Visually inspect the engine earth lead (LHS behind the reaction tie plate. If in doubt run a thick cable (jumper lead) from the battery negative terminal to the engine.

  3. Check power to coil.
    Remove the positive connector to the coil. Put a 12v test light in series and turn on the ignition. The light should come on and be steady.
    Jiggle ignition key to eliminate switch fault.
    If no power, run a wire directly from the positive battery terminal to the positive coil terminal and try ignition. If it works problem is between battery and positive terminal wire. Check fuse 7 and chase wiring with multimeter. Recheck ignition switch. NB starter button will not affect spark.

  4. Check points are opening and distributor is turning.
    You can do this visually. Remove dizzy cap and get someone to crank the engine. You should see the points open and close. Use a torch; it’s dark down there.
    Put a 12v test light between the negative coil terminal and the black/white wire to the distributor. Crank the engine. The light should flash off and on as the points open and close. This should work with electronic ignition modules as well because what you are testing is the circuit through the points (mechanical or electronic) to earth.
    Note: the light may stay on or off when not cranking depending on whether the points stop closed (likely) or open (unlikely). This isn’t important.
    Check the points gap (14 to 16 thou) and inspect the electrode faces for pitting. If any doubt replace points and reset gap. Even when you’re sure it’s not the points, suspect them. It’s always the points.

  5. Condenser.
    A dead condenser looks just like a good condenser. Just replace it. They can be tested with an ohmmeter but if you put a new one in and it doesn’t fix the problem it probably isn’t the condenser.

  6. Check the coil.
    If the points are working and the condenser is OK. Get a spark plug and a plug lead. Connect the plug lead into the HT coil connector. Earth the plug by resting it next to a head nut. Turn on the ignition. Use a nonconductive (plastic) tool and open and close the points manually. (Alternatively you can connect a wire to the negative LV connector and tap this on an earth.) There should be a spark on the plug each time the points open. If you have spark the coil is OK. Move on to 6.
    If NO spark AND you are happy with 1-4 above, the coil may be faulty. Check the resistance of the low voltage (primary) circuit by connecting an ohmmeter to the two LV terminals. This should be between 0.5 (low resistance/sports coil) and 3.5 ohm (standard coil). Check the HT (secondary) circuit resistance by measuring between either LV terminal and the centre HT terminal. This should be in of the order of 5000 to 15000 ohm. Note that coil failure can be exacerbated by heat so even if it checks out cold it may be faulty hot.
    Replace the coil anyway with a known good one. (You can just sit one next to the old one and connect the 3 wires to it).

  7. Leads
    Remove the coil HT lead. Inspect for cracking or corrosion. Coolant can leak from the thermostat housing down onto the top of the cap and cause corrosion, especially with “screw in” contacts.
    Check resistance with ohmmeter; it should be virtually zero with copper core wires.
    Check the resistance of each of the plug leads by removing the plug cap and using a multimeter between the end of the wire and the corresponding contact inside the distributor cap. With copper core wire it should be virtually zero. If not check the cap socket for corrosion.
    Modern cable resistance is more complex and you would need to check the figures with the manufacturer. As a general guide though a lead should be between 2000 and 8000 ohm.

  8. Plug caps
    The original plug caps have a carbon resistor in them. They will have a resistance somewhere between 5000 and 15000 ohm. Modern or reproduction caps should be spot on 5000 ohm. If you suspect the caps, replace or eliminate them. You can solder a ring connector onto a fine 1” self-tapping screw. Screw this into the lead in place of the plug cap. Use the ring connector to connect directly to the threaded end on the spark plug.

  9. Spark plugs.
    Remove the plugs. Check for fouling and check gaps. If no success, replace with new plugs.

  10. Distributor cap
    Inspect for cracks or corrosion. The cap really should look brand new inside. Clean up the lead connector sockets if at all corroded. The central contact for the rotor button should have a resistance of the order of 30000 ohm. If the cap looks OK still try replacing it with another one, or a known good cap and set of leads.

  11. Rotor button
    Inspect and replace if it looks worn, pitted, burnt or otherwise faulty. Try another one anyway if it looks OK.

  12. Distributor
    Remove the distributor and carefully inspect it. Ensure that it wired correctly. Specifically check the insulators between the points and the coil and capacitor leads are in the correct place.
    Check that that the coil lead is connected and conducts to the capacitor lead.
    Check that the internal earth lead is connected to the distributor body and the centre plate.
    Check that the distributor turns freely and is mechanically intact.
    Check that there are no small screws or other foreign parts loose inside or causing a short.

  13. Other things
    If you have got here and not fixed the problem.
    The checklist above is fairly complete. Sometimes though electrical components can look OK but be faulty. Replacing each component, one at a time, with a known good (not necessarily new) component will sometimes smoke out a mystery.

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I had them die by the bucket load: that’s why I always kept quite a few on hand, and it’s why absolutely detest points and condenser.

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I think that Steve needs to clarify. I read his statement as one second the engine was driving the car and the next the car was driving the engine. The “you can feel a loss of power” is ambiguous as it isn’t clear whether the “loss” is a gradual reduction or instantaneous cut off. When my ignition switch cut off for the first time the first thing I noticed was a “loss of power” - ie I was slowing down and pressing the accelerator did nothing. My interpretation of what Steve described was the same as my experience.

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WOW! thanx guys. If i want to do any post-failure in-situ testing, gonna need my mechanic, as my wife won’t go on such a sojourn and I might need her to rescue me while waiting (again) for the tow truck.
The failure of ether to at least start the car, leads (cheap pun) me to ignition. Could swap out the new condenser for the old one. My mechanic and I discussed the possibility of the i-switch…so that’s high on my list. The consistency of the data and the acute failure of the system, without sputtering or classic symptoms of lack of fuel, lead me away from a fuel problem, plugs, plug wires, points and dizzy problems. thanx again guys and more later. s

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Does your car have a ballast resistor? If so, could be when it warms up, failure occurs, cools off, back in business.

no ballast resistor.