Engine suddenly cut off when idling

[hspeck]

It's been some time, but I have been enjoying my Esprit for the pass few months without issue.. was enjoying it tremendously

However, on 12 April, the engine suddenly died whilst I was crawling in start stop traffic. No symptoms, the engine just went dead. I managed to restart the car after several tries. The car drove well after that, and had no problems whatsoever. I use the car daily.

But on 22nd April, the same thing happened again, but this time I was waiting at the traffic light, and traffic was smooth with no congestion. The engine just died, no spluttering, rough engine noise whatsoever. I managed to start the car again after about 6-7 cranks... and then the car drove normally again.

And then the same thing happened again on 23rd April. There were no symptoms, everything felt fine, engine sounded fine. It was like someone just turned off the engine, and it simply went dead. It was like when we turn off a light switch, it simply went off. The car started again after I cranked the engine maybe less than 10 times. All these lasted less than 10mins, and the car died at the same spot as per the previous day.

Between 12 Apr and 22nd April, I was still using the car as per normal and nothing happened.

Some helpful folks in the FB group suggested that there might be an intermittent break at the pick-up coil wire, so yesterday i proceeded to do the various test as per the service notes. All the voltages at the coil was as per spec, and the resistance across the coil wire was 3.58kΩ, which was also within spec. I also tried wiggling and twisting the pick-up wire at several points but there was no difference to the resistance. I checked the sparks on all the plug leads and also the lead from the coil to the distributor and everything looks to be good.

Thinking maybe it was due to the carbs being unbalanced and maybe there was fuel flooding, so today I readjusted the carbs and rebalanced them.

After everything was done, which took about 30-35mins, i left the car running for about another 10mins. I was satisfied and as I was starting to keep my tools , the engine suddenly died again. Just a clean cut-off... no symptoms whatsoever. I tried to start the engine again 1 time but was unsuccessful. So i check all the voltages and the coil pick up resistance again. All readings were again within spec. After about 3mins, I started the engine and this time it started without much issue. I did not even need to press the accelerator pedal like the previous 3 times. I think it started this time because I might have flooded the carbs the previous 3 times the engine died. I was anxious as there was many cars behind me then.

Few things to note is that the 1st time it happened I drove about 9km for about 15mins before it happened, and the 2nd and 3rd time i drove for about 1km.

I did notice that when the engine died, the fans were still running, so it doesn't looks as if the electricity was cut off when the engine died...

I was thinking it might be a heat soak issue the first 3 times, but everytime i noticed the coolant temp was barely 80⁰C. 

I am at a loss on what to do and would appreciate any thought and suggestions on what i should check.

Thank you.

 

 

[andydclements]

I think you'll be best to diagnose it when it is in a failed state. Even if you can only get as far as finding out which element is amiss (loss of spark, lack of fuel etc).

I ad an intermittent problem on an Excel which was due to the rotor arm breaking down when hot. I don't think that's your problem, but it was much easier to diagnose and resolve once I knew that I was loosing spark when hot.

[Sparky]

I'd be investigating fuel delivery.  Next time it happens, immediately check carb float chamber levels.  Are the fuel tanks original?

[drdoom]

11 minutes ago, andydclements said:

I think you'll be best to diagnose it when it is in a failed state. Even if you can only get as far as finding out which element is amiss (loss of spark, lack of fuel etc).

I ad an intermittent problem on an Excel which was due to the rotor arm breaking down when hot. I don't think that's your problem, but it was much easier to diagnose and resolve once I knew that I was loosing spark when hot.

I'm with Andy on this, as a sudden cut is not typical of fuel related issues in my experience. Fuel shortage usually causes misfire for a short time prior to the cut and if you had fuel starvation it would manifest most clearly when the demand was up, as when driving rather than at idle. Also, residual fuel in the carbs permits holding off a stall via some shots from the accelerator pumps after reduced levels in the bowls begin to trouble the slow run system, helping to establish that fueling is the problem. I had Lumenition serving wonderfully on a Lotus for 12 years without trouble, however was once stranded on a road trip when a rather new rotor arm had dielectric failure shorting HT spark to ground via the shaft. Recommend you replace the cheap ignition bits ASAP as first, easy step in diagnosis.

Cheers

[hspeck]

8 hours ago, Sparky said:

I'd be investigating fuel delivery.  Next time it happens, immediately check carb float chamber levels.  Are the fuel tanks original?

Yes Sparky, the fuel tank is original. Initially I was thinking that the carbs were flooded, instead of fuel starvation. But on second thought, I do not think it is a fuel issue. I have experienced engine dying due to fuel starvation in my other cars, and usually it dies after some spluttering, not as clean cut as this instance. Thanks for the suggestion, I will look into it if the other test don't produce any results. 

[hspeck]

8 hours ago, andydclements said:

I think you'll be best to diagnose it when it is in a failed state. Even if you can only get as far as finding out which element is amiss (loss of spark, lack of fuel etc).

I ad an intermittent problem on an Excel which was due to the rotor arm breaking down when hot. I don't think that's your problem, but it was much easier to diagnose and resolve once I knew that I was loosing spark when hot.

I was thinking to check that, but I need another person to help me crank the engine. Unfortunately I was alone when the engine died. 

I will try to replicate the problem. If I can do that constantly I will drive to my friend's place and ask him to help to crank the engine while I check the sparks and other specs. 

8 hours ago, drdoom said:

I'm with Andy on this, as a sudden cut is not typical of fuel related issues in my experience. Fuel shortage usually causes misfire for a short time prior to the cut and if you had fuel starvation it would manifest most clearly when the demand was up, as when driving rather than at idle. Also, residual fuel in the carbs permits holding off a stall via some shots from the accelerator pumps after reduced levels in the bowls begin to trouble the slow run system, helping to establish that fueling is the problem. I had Lumenition serving wonderfully on a Lotus for 12 years without trouble, however was once stranded on a road trip when a rather new rotor arm had dielectric failure shorting HT spark to ground via the shaft. Recommend you replace the cheap ignition bits ASAP as first, easy step in diagnosis.

Cheers

At this point I also do not think it is a fueling issue, as I am able to drive long distances after I restart the engine without any issue. 

I will try to replace the ignition parts, starting with the coil pack as that is the easiest. 

I do have a set of Powersparks coil and electronic distributor set. I was told that I do not need to use the ignition amplifier with their set up, but I am not sure how it is possible as there is still a set of wire from the distributor which I presume is to be connected to the amplifier. Do you have any experience with electronic distributor setup on the Esprit? 

https://simonbbc.com/powerspark-lucas-45d-distributor-electronic/

Thanks 

 

[ramjet]

I would be tending to think electrical. Especially if it is instantaneous with now warning. As to what it is though I would not be sure.

It sounds like something to do with feed to the coil or distributor though? Only common parts in the circuit as well as a couple of wires and a lead.

[ekwan]

11 hours ago, Sparky said:

I'd be investigating fuel delivery.  Next time it happens, immediately check carb float chamber levels.  

Do you need to go through all that complication. After the engine dies on ya, I'd be pulling off the fuel supply hose to the carburettors and see if there's any fuel in that. Yes? No?

[drdoom]

No. Pulling a fuel hose is bloody messy and raises risk of fire when spillage turns to vapour on a warm engine. Replace the distributor cap and rotor before you get at anything else, they are inexpensive, not terribly hard to exchange and have been known to give just the sort of trouble experienced here.

[ekwan]

8 minutes ago, drdoom said:

No. Pulling a fuel hose is bloody messy and raises risk of fire when spillage turns to vapour on a warm engine. Replace the distributor cap and rotor before you get at anything else, they are inexpensive, not terribly hard to exchange and have been known to give just the sort of trouble experienced here.

Never had that issue of a fire provided you do it carefully (ignition off, of course). There is no residual pressure in a carburetted system, unlike an injection one. 

[hspeck]

2 hours ago, ekwan said:

Do you need to go through all that complication. After the engine dies on ya, I'd be pulling off the fuel supply hose to the carburettors and see if there's any fuel in that. Yes? No?

I do not think that it is a fuel problem, at least not at this point of time.. So I will not be pulling any fuel hose.. Yet... Hahah

4 hours ago, ramjet said:

I would be tending to think electrical. Especially if it is instantaneous with now warning. As to what it is though I would not be sure.

It sounds like something to do with feed to the coil or distributor though? Only common parts in the circuit as well as a couple of wires and a lead.

Thinking it might be something along this line now, but I did check the voltages at various point along the ignition system immediately when the engine died. All were to spec though... 

2 hours ago, drdoom said:

No. Pulling a fuel hose is bloody messy and raises risk of fire when spillage turns to vapour on a warm engine. Replace the distributor cap and rotor before you get at anything else, they are inexpensive, not terribly hard to exchange and have been known to give just the sort of trouble experienced here.

I may start by replacing the coil and see what happens.. Have to relook again at the ignition circuitry in the service manual.. If I need to replace the rotor and cap I will probably use my newset of electronic distributor and coil.. 

 

Thanks 

[ekwan]

5 minutes ago, hspeck said:

I do not think that it is a fuel problem, at least not at this point of time.. So I will not be pulling any fuel hose.. Yet... Hahah

Love a man with a plan. 🤣

[chris]

I had this some years back and ended up removing the dizzy and replacing the pick off and cables. Ive also heard that people have had problems with the cable that goes from the ignition amp to he pick off. Apparently the wires degrade within the environment of the engine bay. When was the last time that the electronic pick off wires/cables were changed on yours? 

Although this cured my issue for several years I ended up having a spate of ignition issues with my turbo and eventually just converted it to a crank sensor wasted spark system.

I’ve also heard that ignition amps have had intermittent issues but they are very pricey to change. 

Due to the fault being intermittent I think you will have to change components and see if it happens again. Personally I’d change as much as I could afford from the pick off back through the amp to the coil. Not great engineering practise but less chance of further breakdowns. 

SJ Sportscars list the following parts: amp £175, lead from amp to dizzy £28, pick off with cable £56, no idea if they are in stock though.

good luck

[Barrykearley]

5 hours ago, ekwan said:

Do you need to go through all that complication. After the engine dies on ya, I'd be pulling off the fuel supply hose to the carburettors and see if there's any fuel in that. Yes? No?

He’s right though. If them fuel tanks are original - then it’s amazingly common how rust and crap going through the lines can cause such symptoms 

[ekwan]

55 minutes ago, Barrykearley said:

He’s right though. If them fuel tanks are original - then it’s amazingly common how rust and crap going through the lines can cause such symptoms 

Latest diagnostic flow chart.........

[Barrykearley]

44 👍

[hspeck]

1 hour ago, chris said:

I had this some years back and ended up removing the dizzy and replacing the pick off and cables. Ive also heard that people have had problems with the cable that goes from the ignition amp to he pick off. Apparently the wires degrade within the environment of the engine bay. When was the last time that the electronic pick off wires/cables were changed on yours? 

Although this cured my issue for several years I ended up having a spate of ignition issues with my turbo and eventually just converted it to a crank sensor wasted spark system.

I’ve also heard that ignition amps have had intermittent issues but they are very pricey to change. 

Due to the fault being intermittent I think you will have to change components and see if it happens again. Personally I’d change as much as I could afford from the pick off back through the amp to the coil. Not great engineering practise but less chance of further breakdowns. 

SJ Sportscars list the following parts: amp £175, lead from amp to dizzy £28, pick off with cable £56, no idea if they are in stock though.

good luck

some folks in FB also suggested the pick up wire from the amplifier.  I have checked the resistance and it was within spec, so i am leaving it for later when I have to touch the distributor

the lucas AB14 is really expensive, but I do know that it is actually a GM part when we open the cover. I had some issues with the amplifier when I just gotten the car, and have replaced the part if i remember correctly. I think the biggest problem was getting the correct diode ... I will need to go through my posts here again to find the correct part number i think ..

thanks

1 hour ago, Barrykearley said:

He’s right though. If them fuel tanks are original - then it’s amazingly common how rust and crap going through the lines can cause such symptoms 

I am not sure, but it does not seem to point to fuel issues as the engine dead instantly without any spluttering or any obvious fuel starvation .. I will look into it if changes to the ignition system doesn't solve the problem

thanks

[hspeck]

i have a spare set of these and am thinking to replace them if i need to replace the coil pick up or wires at the distributor 

https://simonbbc.com/powerspark-lucas-45d-electronic-distributor-high-energy/

https://simonbbc.com/viper-dry-ignition-coil-high-energy-in-chrome-aluminium-finish/

according to Powerspark we do not need the ignition amplifier with these 2 items,

thoughts?

thanks

[jonwat]

1 hour ago, hspeck said:

https://simonbbc.com/viper-dry-ignition-coil-high-energy-in-chrome-aluminium-finish/

Says it's not suitable for vehicles with ballast ignitions. 

[ekwan]

1 hour ago, hspeck said:

I am not sure, but it does not seem to point to fuel issues as the engine dead instantly without any spluttering or any obvious fuel starvation .. I will look into it if changes to the ignition system doesn't solve the problem

thanks

Obviously never operated a petrol lawn mower before. 😎

Edited April 28, 2019 by ekwan

[andydclements]

16 minutes ago, jonwat said:

Says it's not suitable for vehicles with ballast ignitions. 

In which case, just convert to non-ballast wiring. 

a 12v coil is in reality a 6v coil. With a ballast (resistor) system the coil normally gets 6v and the ballast gets 6v by wiring in series, then when cranking the coil gets a supply directly from the supply which will drop to c10v so that the coil doesn't get too little supply. Non-ballast system just gets battery supply in either situation.

So, simple enough to disconnect the ballast.

[andydclements]

1 hour ago, hspeck said:

 

I am not sure, but it does not seem to point to fuel issues as the engine dead instantly without any spluttering or any obvious fuel starvation .. I will look into it if changes to the ignition system doesn't solve the problem

thanks

I've had ignition problems that grow such as starting with occasional misfire , and others that are instantaneous where the engine just dies. Ditto fuel problems. 

Although the differing on-set can be more common with one type of fault, it's not absolute parity, so don't rule out fuel just by the way it manifests.

[hspeck]

1 hour ago, ekwan said:

Obviously never operated a petrol lawn mower before. 😎

Nope never.. Cannot afford a house here in Singapore... We live in flats hence no lawn to mow

[hspeck]

2 hours ago, jonwat said:

Says it's not suitable for vehicles with ballast ignitions. 

 

1 hour ago, andydclements said:

In which case, just convert to non-ballast wiring. 

a 12v coil is in reality a 6v coil. With a ballast (resistor) system the coil normally gets 6v and the ballast gets 6v by wiring in series, then when cranking the coil gets a supply directly from the supply which will drop to c10v so that the coil doesn't get too little supply. Non-ballast system just gets battery supply in either situation.

So, simple enough to disconnect the ballast.

Sorry but where is the ballast located? I don't recall seeing any in the ignition box... 

And the wiring diagram did not show any resistor/ballast either

1 hour ago, andydclements said:

I've had ignition problems that grow such as starting with occasional misfire , and others that are instantaneous where the engine just dies. Ditto fuel problems. 

Although the differing on-set can be more common with one type of fault, it's not absolute parity, so don't rule out fuel just by the way it manifests.

Yes, I am not ruling out a possible fuel issue. Just that I need to make sure it is not the ignition system before I look at the fuel.. 

Thanks

[ekwan]

43 minutes ago, hspeck said:

Nope never.. Cannot afford a house here in Singapore... We live in flats hence no lawn to mow

Thought I'd remind myself living in this wretched apartment on Beach Rd. 🤣