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Awful day out
JeffHs - 10/4/17 at 09:05 AM

Made the mistake of going for a drive in the Peak District yesterday. Normally quiet lanes were full of parked cars and people fannying about on foot, bikes and cars. The car had started to splutter and misfire but I thought it would clear if I could give it some beans. It's misbehaved before but has never actually given up but I got stuck in stationery traffic and the engine died and would not restart. I had a look under the bonnet and couldn't find anything obvious. It was hot but the carbs were cool and full of fuel and I had no mobile signal, so decided to let it cool down and after 15 minutes it restarted. At that point I should have turned round and gone home but no, I pressed on and got stuck again in horrendous traffic and broke down a further 4 times, the last one on a very busy main road on the brow of a hill and no way to get off the road. Very popular I was. Eventually it restarted and I carried on only to get into a massive queue to get through Ashbourne. Although it was going to put me a lot further from home I decided to U turn and head for quieter roads. The car ran like a dream for the next 20 miles with no problem at all, so my misfire from last year is still there, goes away by itself and is still a mystery.
I think it must be a heat related issue so once it had some decent airflow through the nose it was ok but the water temperature never looked silly even when it was failing.
Very stressful day, I think it must be 25 years since I last had a breakdown.

Last year's misfire thread
https://www.locostbuilders.co.uk/viewthread.php?tid=204745


CosKev3 - 10/4/17 at 09:15 AM

Sounds fun!

Weekends on our roads are a waste of time if you want a nice peaceful blat I've found in the kit car

Luckily I work shifts so only have one weekend off a month,so plenty of days off in the week when the roads are way quieter


BenB - 10/4/17 at 09:16 AM

That sound horrendous- could be fuel evaporating / vapour locking. Our cars get attention whether we like it or not. When we're broken down it's the wrong kind of attention. I can remember breaking down on the North Circular in North London. I had to run around the North Circular and up / over a footbridge to the local petrol station (I'd run out!!!) to get a jerry can full of petrol. As I was filling the car back up again from the jerry can with cars swerving round me a car behind did a double toot on the horn- in my slightly frazzled and knackered mindset I wasn't in the mood and swung round with the middle finger raring to go- thankfully I spotted it was a police car before I turned round fully- they'd parked behind me with the blues on to warn other drivers


mcerd1 - 10/4/17 at 09:31 AM

quote:
Originally posted by JeffHs
Last year's misfire thread
https://www.locostbuilders.co.uk/viewthread.php?tid=204745


What have you tried since last years issues ?


wylliezx9r - 10/4/17 at 09:50 AM

I went out for a spin in the Brecon Beacons on Sunday in my VX220. I got to Brecon at around 0730 and had about 50 mins of quiet roads and excellent driving by 0830 the roads were packed and a nightmare so I drove home and did some DIY


JeffHs - 10/4/17 at 10:02 AM

"What have you tried since last years issues ?"

I checked out the carbs, checked everything was tight, float levels ok. I changed the old coil for a new one. I really thought it was the coil in the first place, so nothing else and it's been ok since until yesterday.


Norfolkluegojnr - 10/4/17 at 11:09 AM

is it simply overheating? what was the temp reading when it was breaking down?

my personal experiences of crossflows (ive had three in seperate cars) is they are temp sensitive. You need a good rad, and the correct thermostat. I had the exact same issues on track days in the past. would get hot, then idle badly, then die. Once cool, would work fine again.

What rad, thermostat etc are you using? electric fan fitted?

EDIT: saw you posted temps not bad. Where is the temp sender plumber too? perhaps its giving a false reading?

[Edited on 10/4/17 by Norfolkluegojnr]


Mr Whippy - 10/4/17 at 12:10 PM

sounds like the fuel boiling in the carbs or pipes, my Cortina was bad for this. Actually took the carb top off and the fuel was literally bubbling and boiling in the float chamber spurting fuel down the jets! an extra thick plastic carb gasket was all that was needed to cure it totally. Carbs are a pain in the butt either to could and freeze or too hot and boil... This is why car manufacturers used temp controlled air valves and hot air heating, try and put a simpler air filter on without this and you have issues.

Do you have the fuel lines close to the exhaust or engines? My JBA Falcon with the pinto was a nightmare for the throttles freezing wide open on the motorway when it was 7 degs, then would backfire and cut out. Didn't over heat as it had plenty of air coming in past the engine.


JeffHs - 10/4/17 at 12:52 PM

Thanks for all the suggestions.
Answers to your questions - Polo rad with VW sender, electric fan, can't remember exact thermostat rating but it was sensible. Temp gauge was above normal but still mid range.
Carbs are on a long manifold so not too close to engine and felt cool when engine died, so unlikely to be fuel boiling. Pinto mechanical fuel pump. pipe work not too close to the engine.
Just a thought. My carbs have trumpets and no filter so the front trumpet is very close to the bonnet and there is no side cutout, they just suck
under-bonnet air. What effect apart from a slight loss of power would hot intake air have, bearing in mind that the carbs don't seem to be too hot?
I think my next move is to revert to the standard Ford DGAV and see how that goes (although I've never been able to cure a bog down on accel with that setup).


r1_pete - 10/4/17 at 12:57 PM

Are you running the stock x flow distributor? If so check the earth brade between the points plate and the distributor body, if its dodgy sitting at tickover on max vacuum can cause it to break connection and cause the misfire.


Norfolkluegojnr - 10/4/17 at 01:01 PM

quote:
Originally posted by JeffHs
Thanks for all the suggestions.
Answers to your questions - Polo rad with VW sender, electric fan, can't remember exact thermostat rating but it was sensible. Temp gauge was above normal but still mid range.
Carbs are on a long manifold so not too close to engine and felt cool when engine died, so unlikely to be fuel boiling. Pinto mechanical fuel pump. pipe work not too close to the engine.
Just a thought. My carbs have trumpets and no filter so the front trumpet is very close to the bonnet and there is no side cutout, they just suck
under-bonnet air. What effect apart from a slight loss of power would hot intake air have, bearing in mind that the carbs don't seem to be too hot?
I think my next move is to revert to the standard Ford DGAV and see how that goes (although I've never been able to cure a bog down on accel with that setup).


You could be starving the one closest to the bonnet of air. I wouldn't recommend running without a filter in any case. is the fuel pump creating enough flow/pressure? what carbs are you running?

have the carbs been properly balanced / set up? make a HUGE difference.


adithorp - 10/4/17 at 02:22 PM

Check the valve clearances. If they're too tight you'll get those symptoms when hot.


snippy - 10/4/17 at 04:58 PM

I was having the same issues 2 years back. Intermittent breakdowns, let it cool, then restarted. Drove off, same thing happened again 20 min later. For me it was the fuel pump failing. A new pump solved the problem. Might be worth you trying another pump?
I


steve m - 10/4/17 at 06:08 PM

Ive had similar problems with my xflow 16-18 years ago, and the fix was a new 12volt coil, as I had cut up the original wiring and was running 12volts through a 6v ballasted coil, that resulted in me breaking down twice to donnington, and twice home
we only found that out when I rested my hand on the coil, and you could of cooked on it

xflows can run at ridiculously high temps

Fuel pump could be an issue, or a partial blockage in the fuel supply ?


rusty nuts - 10/4/17 at 07:10 PM

Had similar problems with mine , it now has vents cut out of the nose one just behind the rad , rear vents in the bonnet , an air intake through the side of the bonnet and also heat wrap around the exhaust manifold which I think is what cured the problem. Nest time we have a hot day try leaving the car idling with the bonnet off then retry with it on to check for under bonnet temperature problems.


David Jenkins - 10/4/17 at 09:20 PM

quote:
Originally posted by steve m
Ive had similar problems with my xflow 16-18 years ago, and the fix was a new 12volt coil, as I had cut up the original wiring and was running 12volts through a 6v ballasted coil, that resulted in me breaking down twice to donnington, and twice home
we only found that out when I rested my hand on the coil, and you could of cooked on it



I was going to mention the coil, but I had a moment of doubt and decided not to post a reply... but I do remember this being discussed here quite a few years back. The coil will cook if you have the wrong type on an unballasted ignition circuit, and can stop working until they've cooled down again.

[Edited on 10/4/17 by David Jenkins]


JeffHs - 11/4/17 at 05:49 AM

I have a very silly suggestion. All of my symptoms are consistent with carb icing. It's unlikely to be the coil because it's a new replacement and clearly has not fixed the problem.
It is normally a very easy clean starter but each of the restarts after it died were spluttery and accompanied with loads of black smoke suggesting a very rich mixture temporarily.
Can it really ice up on a 23 degree day with high under bonnet temperature?


steve m - 11/4/17 at 06:24 AM

I believe the answer is no, as carb icing from my ppl days happens with a change of air temperature as in climbing or decending


rusty nuts - 11/4/17 at 07:23 AM

You would get very similar symptoms if the fuel is boiling due to high under bonnet temperatures


JeffHs - 11/4/17 at 07:27 AM

Agreed but the carbs felt cool (cold) when it first died.


BenB - 11/4/17 at 09:01 AM

Vapour locking can happen at any point in the fuel circuit- does a fuel line run near the engine at any point?


gremlin1234 - 11/4/17 at 11:57 AM

symptoms could be due to over-fueling, possible fuel pump pressure too high.

but I agree vapour lock is the thing to look for.


rusty nuts - 11/4/17 at 07:27 PM

Summer of 82 or 83 was very hot for a couple of weeks and I went out on loads of breakdowns most of which were down to fuel vapouring. On several of the cars we ended up fitting new fuel pumps . Unleaded fuel vaporises quicker than leaded.
Just remember, the old Fiat X19s had a very bad hot starting problem due to vaporising, fitting an electric fuel pump cured the fault

[Edited on 11/4/17 by rusty nuts]