E-type - problem - not purring at the moment!

[e42]

Hi, bit of a ramble this, but here goes..

I have a S1 E4.2 and wondered if any one can help me with an intermittent problem! I took the car for a run on Saturday, covered about 15 miles at varying speeds, no problems at all. Then parked up while my wife grabbed a bit of shopping, car standing for about 30 mins or so in the sun. Then set off to the pub for lunch and within about half a mile she (the car, not the wife) started to cough and splutter and seemed to run on 3/4 cylinders before petering out. No luck re-starting straight away, but after waiting for 5 mins started up and ticked over nice and smooth.

Set off then same symptoms after about a mile, engine stopped, waited 5 mins, re-started, etc. This happened twice more over the next 3 miles or so (decided to risk getting to the pub for lunch).

Car standing for about 90 mins over lunch, then same problem a mile down the road. After that, the car seemed to run fine until I got back home, another 5 miles or so.

I swapped the distributor last year for a 123 and replaced the coil and plug leads, all have covered about 1000 miles since then through last summer with no problems.

Any ideas much appreciated, or any specialist you might recommend in the NW to take a look!

Dom

[Carsie]

Just happened to log on and saw your problem - sounds like fuel starvation. No doubt the real experts on here will sort you out. Stale fuel, sticking dashpot, dirty filter, sticking SU points - its all well documented - Sounds like you have a lovely car- I wish I could get my Elan back on the road

Edited by Carsie on Monday 12th April 10:39

Edited by Carsie on Monday 12th April 22:40

[e42]

Hi, thanks for the reply - if I could afford a second classic (and if I had the space) an Elan would be top of the list!

Good thought about fuel starvation though, I'll investigate a bit further - the problem is a bit annoying (especially now the weather is getting better) because I can't really rely on the car at the moment and I have a feeling it's something fairly simple...

I don't suppose it could be an overheating coil?

Dom

[JacksHereR]

this reminds me of a problem i had... turned out the 'rubber' I used to make a petrol cap seal.. broke up under petrol and time, and the rubber didnt float.

a flap of rubber was sometimes blocking the fuel line, would be fine for ages.. then a slight bump or pothole would dislodge it to block fuel again

[Huntsman]

e42 said:

I don't suppose it could be an overheating coil?

Dom

Could be.

Carry a sapre plug, next time it does it, pop the nose up, pull an HT lead, put the spare plug in and have someone crank her over to check for sparks. It can be the case that a plug in open air will spark but not under compression so its not a definiteve test but a good start and easy.

Sounds more like fuel to me.

[AJAX50]

Could be the condenser, the spark plug test is a good idea to help with the diagnosis.

[lowdrag]

Sounds definitely fuel starvation and not electrics. Firstly, check the fuel filter. If it is blocked that could be the problem. If the tank has rusted inside there'll be a brown sludge in the filter. While the filter is disconnected, put a can on the end of the petrol pipe and run fuel through by turning on the ignition and check the colour for dirt in the system. If it runs fine and the flow doesn't diminish then you know there isn't a problem from the tank forwards. If there is, then it could be the fuel cap not venting and a vacuum build-up in the tank causing starvation. If the flow does slow then take the fuel cap off and try running fuel through again - it shouldn't slow and all you need is a new cap or clear the small breather hole in the top.

If the fuel is flowing then we have carb problems, possibly caused by insufficient use (as indicated by 1,000 miles in a year) and the needles may have laquered up as the fuel evaporated. You need a good strip and clean of the carbs in that case.

Go from there and if the problem persists then drop me a line.

That being said, what fuel pump do you have? They are well known to cause problems from time to time but usually they work or stop with no in between so I for the moment would discount it anyway.

[e42]

Hi,

Thanks all for your suggestions, much appreciated. I'll try the initial checks on the fuelling first, then take it from there.

Dom

[V10Mike]

I had very similar problems with my Alvis, was convinced it was fuel starvation. In the end though it was a faulty (new) rotor arm, where the insulation broke down when it got hot, but recovered when it cooled again. No visible evidence at all.

[jagracer]

V10Mike said:

I had very similar problems with my Alvis, was convinced it was fuel starvation. In the end though it was a faulty (new) rotor arm, where the insulation broke down when it got hot, but recovered when it cooled again. No visible evidence at all.

He's got a new distributor, I've done hundreds of race miles with the same type and never had a problem, if it isn't fuel it may be the coil but I doubt it's the dizzy.

To the OP, try the simple things first like removing the fuel cap, is the pump working OK, has it got fuel to the carbs, are the float needles sticking shut or maybe a float has a hole in it and it's flooding. if you've renewed the coil and leads I doubt it's them unless you have the wrong coil fitted and it's burnt out.

Edited by jagracer on Monday 12th April 18:49

[a8hex]

Actually, I think I remember reading a problem with someone on Jag lovers having an issue with the rotor arm on a 123.

I'd still vote for a fuel problem.

Edited by a8hex on Monday 12th April 19:00

[jagracer]

a8hex said:

Actually, I think I remember reading a problem with someone on Jag lovers having an issue with the rotor arm on a 123.

I'd still vote for a fuel problem.

Edited by a8hex on Monday 12th April 19:00

It's a standard Bosch cap and rotor so I suppose there's no harm in changing them and not expensive.

[lowdrag]

Depends on the rotor arm but the symptoms do not concur at all with an electrical fault. The car "coughs and splutters and runs on 4 cylinders before cutting out". Certainly a fuelling problem. If it was the coil then it wouldn't happen after about a mile - coils take longer than that to severely heat up and die. No, I'll take any bet it's fuel starvation here if the problem is as the OP states. In my many years of E-type ownership I've been through them all, including a fuel cap starvation problem; I've changed coils (always a spare in the boot); I've changed enough fuel pumps - (always a spare in the boot; my current problem was a misfire under load which I traced - quite easily - to worn plug leads which have served me well for 22 years. I can't think of any other reason for the car slowly dying than running out of fuel.

[gib6933]

V10Mike said:

I had very similar problems with my Alvis, was convinced it was fuel starvation. In the end though it was a faulty (new) rotor arm, where the insulation broke down when it got hot, but recovered when it cooled again. No visible evidence at all.

I had the very same problem with a lotus twincam engine in a racing car. Took a bit of head scratching to work it out!




To the OP, my money would be on fuel as well.

Edited by gib6933 on Tuesday 13th April 14:23

Edited by gib6933 on Tuesday 13th April 14:24

[V10Mike]

e42 said:

within about half a mile she (the car, not the wife) started to cough and splutter and seemed to run on 3/4 cylinders before petering out. No luck re-starting straight away, but after waiting for 5 mins started up and ticked over nice and smooth.

Set off then same symptoms after about a mile, engine stopped, waited 5 mins, re-started, etc. This happened twice more over the next 3 miles or so (decided to risk getting to the pub for lunch).

Could indeed be fuel starvation, but as voltage bleeds off through the rotor arm the weakest cylinder will drop first, giving a misfire. I may be wrong, but it's an easy one to check. BTW my faulty rotor arm was identical to the one shown for the twincam, so maybe there was a bad batch!

[lowdrag]

Rotor arms are a well know Jaguar problem. If they have the original riveted head (I think one of the usual suppliers are now selling them having had them remade) then usually no problems but most of the after market junk out there fails regularly. I Always carry a spare no matter what - but then again the spares in the boot are so numerous I have trouble getting my luggage in - lol. But, I've not come across this problem of intermittent firing (yes - rotor arm) combined with a spluttering out and stopping by the roadside. I do hope the OP finds the answer and I don't have egg on my face though!

[RW774]

Agreed with all that, but also check the fuel filter in the sump of the tank. Its probably full of crap.

[AJAX50]

Also the breather hole in the filler cap.

RW774 said:

Agreed with all that, but also check the fuel filter in the sump of the tank. Its probably full of crap.

[e42]

Hi,

Thank you all for your opinions and advice, one of the great things about this site is the quality and enthusiasm of the responses - thanks again.

I'm away this weekend and probably won't get my sleeves rolled up until next weekend, but I'll keep you posted!

Dom

[logiedurno]

I have the same problem on my S2 e-type coupe 4.2 litre with triple SU carbs.

Starts and runs perfectly from cold but if parked up for more than 5 or 10 minutes after it has fully warmed up it will not restart until the engine has cooled down again.

The problem is one of fuel vaporisation and vapour lock within the fuel system or carburretors. Modern petrol is more volatile and boils or vaporises at a lower temperature which gives rise to the problem and also explains why running can become rough when the engine is hot and underbonnet temperatures are high.

I have yet to find a suitable fix for this although I can't believe it is a unique problem and I am sure there must be somebody out there who has come up with the solution.

Anyone out there who knows how to fix it please add a post!