Altitude sickness

[Bernard]

Advice required !

Whilst on this last little jaunt across some alpine passes my car had altitude sickness !!!..... at around 1500m ASL with the tanks about a third full we went round a corner and she started to splutter and eventually stop which appeared to be fuel starvation........... this happened twice..
When we did stop (1500 ASL) all we did was open the fuel tanks... relieve a little pressure due to the heat, checked the connections to the fuel pump, checked we had fuel, jumped back in and it started up again and just got us over the top of the mountain pass !
the engine temperature was fine, 90 degrees, the outside temp was around 28 degrees and everthing was going ok up until then, when going back down the hills it was fine and at lower levels the car ran like a bl**dy train..........and has done ever since !!...

any advice would be greatfully recieved

Cheers
Bernard

[Martin K]

Air is less dense at higher altitudes, so a possible cause is the mixture becoming too rich.

However, the lambda sensors should detect this and the ECU should lean the mixture off, so perhaps you have a dodgy lambda sensor?

[Swamprat33]

errr, Lambda sensor, is that only used with a Cat?
I di not think i had one on my 12v.

Tim

[chris.richard]

Lambda sensor samples the exhaust before the cat, and feeds back to the ECU on how lean/rich the mixture is as evidenced by the amount of ?oxygen in the gases.

Looks like 1988 - 12v had Lambda probes

[rutthenut]

Lambda sensor on 24v engine, even if you do without the Cat.

Wasn't a problem with using fuel too quick, and blockage in the tank vent?

J.R.

[Bernard]

Thanks
All interesting stuff guy's...............
Cheers
B

[David May]

Hi Phil, just joined the thread which is all too familiar! My car has always suffered from overheating fuel which gives exactly those symptoms. It always happens at lowish fuel levels, hot weather and particularly high altitudes - all of which induce vaporisation at the intake to the fuel pump. The pump is reduced to pumping petrol vapour, hence no pressure. The 24V is worse, probably due to higher engine-bay temperatures, which can only be slightly improved by lagging the tank. I now resorted to a small oil-cooler in the fuel feed! If you feel the tank, it has probably reached over 50C and the only cure is to let it cool off a bit. Keeping the tank full raises the pressure at the pump intake and it takes longer to warm up.

[Bernard]

Hi David

I am glad that sounds familiar to someone !!!............. I guess it doesnt help that in my infinite wisdom when i built the car in 1989 i decided to paint the fuel tanks with BLACK stonechip !!.... what a great heat absorbing colour !....... when looking round the car i remember thinking when i touched the tanks....... OOOHHHH they are HOT !
Also thinking about it when i did the last sprint section at Abingdon this year the car spluttered its way round the last few long bends !!

Thanks for that......... pity you couldn't make it to Turin .... or even better Maglioli's at Biella where they have the latest Strato's find !!!!! an original Munari safari car !!!!!... and boy does it look rough !!

Cheers

Phil

[chris.richard]

Did you take any pictures Phil?

[Bernard]

Yep !................

[chris.richard]

And.......

[Bernard]

they are very nice .... ta for asking !

[chris.richard]

:p :p :p :p

[David May]

Since he was the only one to actually make it to Torino (and back!) in his Stratos, Bernard no longer feels obliged to communicate with us mere mortals.

[Chris J]

We're not worthy...

...all hail St.Bernard!

[chris.richard]

Guy, speak up for normal mortals!

[GaryFitz]

I was also going to suggest fuel vaporization as apossible cause. I once had an old TR6 which had this problem and there were three cures 1) keep the tanks as full as you can, 2) run cooling coils around the pump to keep the pumps and the fuel as cool as possible and 3) switch to higher quality pumps that generate less heat. The problem on the TR6 was the pump not the fuel in the tank, but I think the solutions might be similar. Perhaps you could also try some relective heat insulation on the tanks.

[guy mayers]

Guy, speak up for normal mortals!

Ok Chris - I also made it to Turin and back. Met Phil at the hotel in Turin and had a few beers.

The event itself was fantastic. The car behaved itself mostly... I'll be compiling a report for the next newsletter in the next few weeks!

Guy

[Shaun II]

Someone left some photos lying around, look here (http://lancisti.net/mkportal/modules/gallery2/index.php?g2_view=core.ShowItem&g2_itemId=29476)
At least one car known to the club.

[guy mayers]

Some more piccies....

San Carlos Square (http://www.flickr.com/photos/tonysphotos/sets/72157594279883665/)

Guy

[Bernard]

Sorry my loyal subjects !
Posted this and just been toooooo busy !!.... wot a laugh !
Will have to send the photo's to some who knows how to make the file size smaller... my camera has 6.0 mega pixel thingy's and are a bit large am out 2morow so will try to do something later in the week
king Bernie

[catswhiskers]

Will have to send the photo's to some who knows how to make the file size smaller..
king Bernie

You could always send them to me for the next newsletter. :D :D :D

I know, nag, nag, nag. :rolleyes:

Mick

[guy mayers]

Mick, work on the Turin Story starts tonight! I'll have to run it past the one with the better memory first though for editing! You'll have it before the next deadline!
Guy

[Arthur]

Now there's a thing - I had exactly the same symptoms on the motorway last summer in the unaccustomed heat. First time I thought it was the fuel pump - even found a rusty steel washer under the power cable. Second time, I considered my options more carefully - engine overheating (100 to 110 with ambient temp around 36 degrees), fuel tank around 1/3 to 1/4 full, and the knowledge that I'm still running the original volcanic rock filter that collapsed on David May some 2 years plus ago.

I've sorted the cooling - (Ford transit cooling core and electric fan on the pipe from the nearside head before it joins the mainstream) - which was good to 33/34 degrees ambient at full bore and in traffic on the motorways around Manchester - and otherwise have resolved to keep the tank minimum half-full in hot weather. (less absorbed heat from engine; higher static pressure at pump through increased head of fuel).
Mind you, it comes down to fuel vapour pressure at the end of the day. I run either Optimax or BP Ultimate from choice, and I believe these use a significant dose of alcohol in the blend. Whether I'd see the same problem with cooking unleaded, I don't know, and how to actually quantify the problem or the cure - I also don't know.
Still, around 30 minutes parked on the hard shoulder - who cares. Except that it cuts without too much warning, and cutting across traffic to get there in a spluttering heap is not much fun.

[Bernard]

Hi Arthur
Do you have any part numbers on the Ford Transit cooling core ?
and am I correct in thinking you fitted this core to the pressure side of the fuel pump and not the suction side (ie fuel tank feeds fuel pump which feeds cooling core which feeds engine)
Cheers Phil

[Arthur]

Bernard,

Sorry for the confusion - I put the core on the engine water cooling circuit. My thought was that a cooler engine would radiate less heat to the fuel tank (as you know CAE tank is inside the roll cage).

To describe that circuit now is probably a good idea before I forget what I've done.

The main water leaves the upper (oval) outlet at the thermostat, proceeds to the radiator upper port, exits the radiator lower port, and returns to the thermostat lower (round) port. Just before it exits the front compartment, it picks up by a 5/8 inch T reducer the heater water outlet.

The heater water comes direct from the 5/8 inch port on the nearside of the block, runs through a stainless braided line to the heater core.

My original cock-up was to put a water-strangling valve in the line to control the heat, rather than control airflow as car manufacturers do. I therefore shut off flow from the nearside block 5/8 port when I had the heater off; conversely I had to have the heater on (and me melting) when I needed the extra cooling.

So my mod was to fit an additional Transit heater core (anything would have done) as a cooling circuit in parallel with the heater. That is, my 5/8 line which heads for the heater matrix now has a T in it, one side to heater matrix, other side to extra core. The returns meet up via a second T, then proceed rearward via the main line. I've put a 7-inch fan on the core, run by the same thermostat as the main rad fans.

I have indeed thought about a petrol cooler, but I can't for the life of me decide where to get the airflow. Possibilities are limited without chopping the body.

So far, the combination of keeping the tank level up, and the engine temps down, has worked. But you just don't know. Panos, for instance, must be in 40-degree heat most of the year - any problems?

All the best

[Arthur]

Bernard, I should say - if I put a cooler in the fuel line, I'd put it in the lowest pressure I could find - that means it would go in the pressure valve relief line back to the fuel tank.

[Bernard]

Arthur
reading David Mays earlier comments he actually fitted an oil radiator in the fuel feed line so i thought thats what you had done, David lives in Italy and is a frequent visitor to the alps and he suffered the same problems prior to fitting this "fuel radiator", but as you say it would be preferrable to fit it in the low pressure side i guess.
Thanks for your comments anyway, its all interesting stuff
Bernard

[PANOS]

Arthur is right, I run in upto 45+ degrees heat in the summer, with the cabin thermometer showing 60-70+ degrees...!!! God knows what the temp is inside the engine bay at the time... But, that great big electric fan placed on top of the engine cover (copied from Chris Smith) seems to to make all the difference. Never had a problem in heavy traffic or blasting down the motorway at 7000RPM in fifth gear for hours... OK, minutes...!!! The water temp does rise a bit to 90-95 degrees from 80, the oil temp much more to 115-120 from 100, but no fuel vapourisation problems what-so-ever, even with the tanks almost empty, but I do use 100 octane fuel which is still available in Cyprus, lucky us...
I said it before, but if I stand behind the car with the fan on I can feel the mass of hot air coming out, enough to roast a small lamb...!!!
In fact I was thinking of increasing the size of the fan, sealing the engine bay all round much tighter, fitting some brush-type draft exctruters (skirts!!!) down the sides of the car and generate some downforce at the same time...!!! Remember the Brabham F1 Fancar...and the Chaparal (I think...) before that...??? Yes, I was there and old enough to understand what was going on...!!!

CIAO PANOS

[Arthur]

Now here's a thing.

Does everyone who's had this problem use a rollover vent valve on the tank breather?
I do - and suddenly got a lamp on in my head. I whipped the valve off to check the opening pressures - and I do indeed have it fitted the right way round - light pressure to breath in, higher pressure to breath out.
But having blown it through (gob pressure only, and no funny comments), it seems to working.
Now then, I used to get a "clunk" from the tank whenever I took the filler cap off, and an occasional "clunk" when starting off with a full tank. Thought nothing of it, always done that, car still goes, etc.
But now I don't. No negative tank pressure at all.

So I'd like to think it's as simple as that - high negative tank pressure caused by sticky rollover vent valve. Time will no doubt tell. If I get stranded again, first thing will be to whip the cap off, and see if the engine goes. If it does, then problem solved.

Incidentally, I had a chat with the the guys at the BP Ultimate stand at the NEC - there is an industry standard figure for fuel vapour pressure (75KPI summer, 60KPI winter) - so we can forget differences in different fuels vapour pressures as being the cause.

[Bernard]

I have now had a Radiator (Mocal oil type) fitted to the suction side of the fuel pump with ducted air thro' it, also a small "breather swirl pot" which is fitted to the tank breather pipes with a roll over vent valve and the tanks have been covered in reflective "stuff"... so hope fully now the fuel will be cooler, the pressure will be relieved out of the tanks and the tanks will be cooler....now all i need is a mountain and sunshine to test it out !!

Cheers
Bernard

[Shaun II]

It's sunny and the roads are dry, you know the way by now!

[Bernard]

Hi Shaun........
Nice thought but i guess i will be stuck with the Peak District in the rain !!
Hope all is well with you and your family.......... and the Beer project !
Cheers
Bernard