Unexplained engine cut out

[mrmorrisminor]

I have been having a little trouble with my standard 1098 saloon. After 20 mins or so it begins to faulter and the dies. After a minute or so at the side of the road you can restart and off you go for another few minutes until the pattern is repeated. It feels to me as if it could be some fort of fuel starvation as when you turn the ignition back on to restart, the petrol pump can be heard ticking rather alot as if it is refuilling the carb.

WORK SO FAR.......

-HT leads were renewed at last service, only 1000 or so miles ago

- I have replaced the points and condenser again but the problem persists

-I am running on a new 'electronic' style petrol pump put on a couple of years ago

-I have checked the fuel filter in the pump

-I've had a good check for corroded connections etc on the coil ditsributer and fuel pump

As the fault is so intermittent it is proving very hard to find. Whilst at the side of the road I have put my test lamp on the live to the fuel pump and coil and both are fine but as I said it re-starts almost stright away so by the time I get the bonet open any dodgy connection could have reconnected!
Has anyone experienced any problems with the electronic fuel pumps? or wiring from the ignition to it? Or is there something more obvious I am missing? I've heard stories of rota arms failing, although it's nothing to do with fuel I think I'll try that next as I'm running out of things to try...

[PSL184]

Electronic pumps are notoriously cr*p so I would try a standard pump first - after that I'd look at trying a different coil.....

[mogbob]

Could be either the rotor arm or coil on it's way out.Was the central HT ( king ) lead , coil end, wet when you investigated ?
A possible indication of a failing coil when the insulating oil in the coil is leaking.

" cheap " solutions first, "costly " ones later, if you are not sure.
I'd try the rotor arm first and then test the coil with your Multimeter ( ignition off...obvioulsy ) before replacing.

Bob

[beero]

Take the fuel pipe off at the carb, get a bottle to put the end of the pipe in and switch on the ignition, you should fill a pint bottle in about a minute. If not you have a blockage or the pump is not delivering.

[Roni]

Years ago I had the same symptoms in a Minor, it would just stop and after coasting to the side of the road and sitting for a little while, it would restart. I learnt that if it happened, I could switch the ign off and on and the problem would go away until the next time. Being an intermitant fault, it was hard to trace, especially when it stopped happening at all. I have my suspicions of the fuel pump (points type) being the culprit but could not confirm that.
It was hard to explain to the female friend I was with one night when the car just stopped out in the country on a dark road. She thought I had done something and thought so even more when the car restarted like normal without me doing anything to it.
Good luck tracking it down.

[chickenjohn]

Roni, you should have lifted the bonnet and pretended to tinker for a minute, aha! I fixed it, berrruuummmm, car roars into life again!

As well as the dodgy electronic fuel pump as highlighted by the Meerkat, my thoughs are have a close look at the "LT lead" connections- these are available for £5 or so and as the terminals had crimped connections to the lead- these can fail after a number of years,

It is the small wire inside the distributor that has a terminal on the outside leading to the coil and the other side connects to points and condensor wire under the condensor nut. It looks like this:-

[bmcecosse]

If it happens after a few miles running - could be a vacuum forming in the petrol tank. Next time - jump out (don't switch off) and take the cap off - listening for air being sucked in! Could be the electronic pump - when the engine stops -is the pump ticking away like mad ? Otherwise - all the usual ignition suspects - yes, even that 'new' condenser - oh and it's 'never' the coil! But - worth trying another one if all else fails!!

[mrmorrisminor]

Thanks for the replies.

The braided wire inside the distributor was replaced when I put the new engine in about 2 years ago but worth a check. When the fault has appeared it has always been in dry weather. I am carrying a spare coil, ht leads and pump ready for the next event and will replace the rotor arm before I next use the car. If it continues I will investigate the fuel side further, vacuum, pump etc. I use the car regularly in all weathers and it has always been very reliable to date......

Fingers crossed

[kennatt]

I had an mgb with the same fault,with electronic pump,reverted to standard su ,problem solved,the electronic pumps are very suspect to say the least

[melanddoug]

I have a Triumph Stag which uses a very similar electronic Fuel pump to my newly-acquired Traveller.

The Stag would sometimes cut out and, after pulling over, turn ignition off and on again, the fuel pump suddenly clacks away happily delivering fuel (which means there was a void to fill!) and all ok again for a while.

If this is what's happening, then this might help:

The fuel pump has points in it, a lot like your ignition points. If they get worn or dirty, then they don't make a contact and the fuel pump sticks/stops. Testimonial was when this happened, I could leave the ignition on, leap out of the car, open the boot (where the fuel pump resides) and tap it with a spanner or something- fuel pump springs into life, and off I go.
Sometimes I could drive over a bump or cat's eyes in the road and that would sort it out!

In a Moggy, the fuel pump is under the bonnet (correct?) so if it conks out again, open the bonnet (the shock might send the fuel pump into action) and/or try tapping the fuel pump near the end where the wires attach.

A new pump points kit was £12 for the Stag - probably similar for the moggy. Or you can just clean them up with a bit of fine sandpaper and they'll last a bit longer. They're inside the end where the wires attach.

Doug

[bmcecosse]

The much despised 'electronic' fuel pumps DO NOT have points in them. You are describing the standard well known fix for the original (and much better) electric pump!

[melanddoug]

oops - my mistake!

[bmcecosse]

Surprised to hear the Stag has an electric pump - was that standard ? My TR7 - same generic engine block - has a mechanical pump driven from the jack shaft as standard. I had imagined the Stag would be the same ?

[melanddoug]

The Stag had the infamous Triumph 3.0L v8 .. used only in Stags (phew!)

I think that and the TR7 engine started out form the Dolomite engine, is that right ?
On the Stag one they seemed to 'optimise out' the fuel pump housing, so leccy pump= standard. which means having to pull over and bop it one now and then is also a standard Stag free 'feature'.

[bmcecosse]

TR7 engine is half of the Stag block - same (ghastly) water pump etc - surprised the Stag doesn't have the mechanical pump.

[rsawatson]

I have had two 'electronic' fuel pumps in the past - both failed and I've since reverted to an original SU type with points. From my experience though, when the 'electronic' pumps break they break - there's no warning and no intermittent operation before the do go.

Is the coil overheating? Likewise, a friend had a problem very similar to you for a very long time - the coil would get hot, refuse to work, then after a short time decide to work again once it had cooled down - and the cycle would reciprocate.

He'd replaced his original coil with a new one, couldn't work it out, and having tested everything else eventually removed the new coil and refitted the old one. It's been fine ever since!

[xpress]

[quote="chickenjohn"]Roni, you should have lifted the bonnet and pretended to tinker for a minute, aha! I fixed it, berrruuummmm, car roars into life again!

As well as the dodgy electronic fuel pump as highlighted by the Meerkat, my thoughs are have a close look at the "LT lead" connections- these are available for £5 or so and as the terminals had crimped connections to the lead- these can fail after a number of years,

It is the small wire inside the distributor that has a terminal on the outside leading to the coil and the other side connects to points and condensor wire under the condensor nut. It looks like this:-

[/quote

Test for LT Lead from Distributor:

"Disconnect the small wire on the side of the distributor. Connect an ohm meter between that terminal and the engine block. With points open you should have 50 mega-ohm resistance, or open circuit. With points closed you should read resistance no more than 1/4 ohm (250 milliohm max). If you do have this good ground connection, then you may have a bad condenser. Weak spark is often the result of a bad condenser (and it's a cheap part to replace). If you see higher resistance here, then you need to clean and check the connections and the circuit path to ground through the points. Start by checking resistance across the contact points. Clean the points if necessary. Also check resistance between the distributor body and the engine block. Clean the clamp plate and underlying surface on the iron mount if necessary".

[Rob_Jennings]

sounds exactly like a friends car.

we looked over it for hours checking coils, pumps, etc....

in the end I found it to be the rotor arm, a bad batch had been going around and fitting a new lucas branded one solved the problem. the one we replaced showed no signs of failure at all, but clearly it had been 'leaking' back to the spindle and so reducing the spark to nothing (more so when engine was warm).

Carry a new arm and if it happens again swap them over and see what you get.