Fuel spill

[Peter Truman]

Well my post is about potential Fuel Spills due to an accident, some time ago I converted my Mk2 Vitesse from a mechanical to electric fuel pump, it mounted in the rear boot and having a drowned suction, for safety and a delayed start so I could get oil circulating I put a dash mounted switch with tell tale lamp, this achieved all my objectives at the time.

Now I had noticed modern cars even non Injection cars including the Stag fitted a Lucas safety automatic inhibit switch which activates in the case of an accident, but that Lucas cylindrical inhibit switch was both difficult to obtain and obviously gold plated, so I did a bit of Googling and found a Mini version which was smaller and as an aftermarket item relatively cheap. At the same time the latest TCCV Courier had an article re fitting same with an electric fuel pump conversion in the TR4-6 section (Bernard Littlewood) so a plan was hatched and a Mini clone inertia switch purchased ($16 locally supplied and free postage).

It was easily fitted on my engine bay bulkhead placed Relay board, and supplied by a dedicated fuse from the new multiple Blade Ignition Fuse Box. I wired the new inertia switch in before the dash switch so if the inertia switch activates the dash switch loses power and the Tell Tale goes out, which should immediately tell me I have a broken circuit, no head scratching.

Oh and I have altered my extra wiring electrical circuit diagram so if needed in the future someone should be able to follow what's what in the car!!

[micmak]

So, I opened BOTH carbs again.  There was no dirt at all in either bowl. I removed the float valve from both carbs, and blew them through in both directions.  The little plunger operated just fine, closing off the flow when pressed down.  But there was no sign of dirt anywhere.  I reassembled everything and the car runs perfectly. But I am still unconvinced that dirt caused this issue.  Why did I not see any dirt at all? Not even the tiniest speck of dirt.   Can I “trust” the car now?  Will it do it again and leave me stranded somewhere?  Is there any other reason why fuel was dumped out from the air filter housing? 

Thanks.

.....Mick.....

[Pete Lewis]

it can only dump fuel if the fuel level becomes to high 

if jets sealing is in trouble it leaks from underside not out the throat 

can be due to replacement pump producing excess pressure which is very common as this overides the float needle valve 

Pete

[Peter Truman]

I've recently been having issues with the front Stromberg carb pis***g fuel but the main issue was the O ring sealing the jet body to the float bowl, firstly the float bowl hole had corrosion which I sanded smooth then the kit supplied O ring was not thick enough to seal, now replaced with one of same dia but a thicker one, but I do need to get an ethanol compatible one. I've also had the same front needle valve gum up, presumably lack of use and modern fuel, there's always something!!

[micmak]

2 hours ago, Pete Lewis said:

it can only dump fuel if the fuel level becomes to high 

if jets sealing is in trouble it leaks from underside not out the throat 

can be due to replacement pump producing excess pressure which is very common as this overides the float needle valve 

Pete

Thanks Pete.  Hmmm....  Well I will leave it for now and see.  I plan on taking the car out today for the first drive since this issue became apparent.  If it happens again, I will look at getting a weaker pump, if that is possible.   I presume there is no way to throttle down the existing pump?

 

.....Mick.....

[johny]

Ah yes there is a way and its putting packing between the pump and block to move its operating arm further away from the cam. The arm gets moved less so produces less fuel pressure👍 Its trial and error without a pressure gauge and of course if too much you could run out of fuel at high sustained engine loads....

[Pete Lewis]

some have even cut a bit off the spring    but you realy need to test the output pressure before you go jumping at our ideas

has the pump been changed  at some time ?????

Pete

[micmak]

2 hours ago, Pete Lewis said:

some have even cut a bit off the spring    but you realy need to test the output pressure before you go jumping at our ideas

has the pump been changed  at some time ?????

Pete

It looks new, and the car was totally restored a few hundred miles ago.   I bought the car a few months ago and I have only done 300 miles or so.  The pump looks brand new and it probably is.   

 

.....Mick.....

[micmak]

I took the car for a little drive today.  When I reached my destination about 10 or 12 miles away, I was parking it, and it stalled.  I decided not to try restarting it, and I walked away to get a coffee.  I came back about 20 minutes later, and the car wouldn’t start.  It nearly did a few times, but it just wouldn’t fire.  I stopped trying for a few minutes, and tried again and again a few minutes apart. Same result.  In the end, it just barely “caught” after about 7 or 8 attempts over a 20 minute period. 

I drove home and it drove just fine.  When I got home, it idled very badly in the driveway.  I decided to take a look at my carbs again while it was still running.  But by the time I got the bonnet open, it had stalled.  It started again but once again idled terribly.  So, it seems to me that whatever is wrong, it is not a problem when the car is cold.  I wondered about fuel evaporization.  But today was not a hot day by any means and I only drove a short 10 or 12 miles.  Also, I was able to touch both carbs with my hand, and they were not particularly hot.  

One more note, when the car was idling badly, the exhaust sounded as if I was holding something against the tailpipe.  I’m sure we have all put our hand against the tailpipe to see if it the emissions are black. Well, that flapping-type sound that you get when doing that, was evident when the car idled badly.   If I just touched the throttle to increase the revs, the sound went away for a moment until the revs died back down and the erratic idle returned.   I first noticed this sound last week but I thought it was the exhaust fumes firing against the number plate of my other car which was parked just inches away from the tailpipe.  Obviously, that idea is wrong.  Not sure what to do next….

 

…..Mick…..

[Pete Lewis]

as it stalled when hot then its basic mixture is just set too rich  you need to lean it down

especially evident if she goes all wooly and pans out as the idle is slowed 

i would start with your mixture settings 

Pete

[micmak]

27 minutes ago, Pete Lewis said:

as it stalled when hot then its basic mixture is just set too rich  you need to lean it down

especially evident if she goes all wooly and pans out as the idle is slowed 

i would start with your mixture settings 

Pete

That was my guess too, Pete.  I have always felt that this car was set too rich.  As I said earlier, I have only had this car for a few hundred miles, but very often when I’d accelerate, I’d feel it kinda hesitate or stumble slightly.  I assumed it was just too rich.  I will take a look at the mixture next, so.  I will not have time now until next week.  I will post my results then.

Thanks.

……Mick…..

[johny]

Do you think the float level issue has been resolved then Mick? If the level is getting too high the mixture will be rich so before anything else you need to be sure its correct. One problem at a time😁

[micmak]

1 hour ago, johny said:

Do you think the float level issue has been resolved then Mick? If the level is getting too high the mixture will be rich so before anything else you need to be sure its correct. One problem at a time😁

I think so, Johny.  I mean there is no fuel spewing out anymore and there is no smell of petrol.  Both carbs seemed clean, dirt-free and fully functional when I had each one apart, so I think that’s ok. Today’s little drive was to “test it out” and see if any fuel spilled out.  
I guess I could remove the air filter, start the car, and let it sit there idling.  If and when it starts to idle badly, I will see if the fuel is being dumped or not.  

[johny]

Certainly no load running is when its most likely to overflow. At the same time watch in the carb mouths to see if theres an excess of fuel coming out of either jet...

[Pete Lewis]

these are basic CD carbs  its easy to turn the bottom jet adjuster with a penny washer or coin ,,or just fingers   turn the adjuster  .listen to the result  if the idle increases keep turning 1/4 turn at a time till it starts to falter and back of a part turn to the best and its done    use ears no need for any colour tune or other miyths to set it close 

Pete

[daverclasper]

On 16/08/2023 at 09:55, Pete Lewis said:

my rorty 1600 with unwrapped 631 and plastic fan , twin stroms, std air box  would idle for an hour without any hint of a hic up 

Not doubting you Pete, though was that in 38c, which is when my car does stumble if in traffic jams for a while, idling and very slow moving.

I don't think the car is running much too rich, going by plug colour and 40mpg (motorway at 60mph, 3.27 diff and overdrive), though I'm not an expert on these things

Edited August 23, 2023 by daverclasper

[Pete Lewis]

was in a june  so more likely 28/32    she is left to run all the time it takes to MOT 

and in all the years of ownership the old girl never missed a beat what ever the traffic or whatever 

Im sure triumph never specified a car design that was made to conk out when the sun came out they tested all over the world to prove things actually worked 

Pete

[micmak]

Hi Folks, due to a hand injury and other “excuses” I only had an opportunity to re-visit my fuel issue today.  I started the car for the first time in weeks, and it was fine.  I let it idle and as it warmed up, it started to struggle to stay running.  I increased the idle screws just to keep it running.  When I revved the car, there was a puff of black smoke from the exhaust.  

I removed the air filter housing and there was nothing unusual to see in and around the carbs while it was running.  I tightened the bottom jet adjusters – just by one “shoulder” of the fitting each time.  There was no noticeable difference in the car’s idle.  I probably turned them both clockwise by 1½ turns in total.  The car’s idle was then running too high, so I had to adjust the idle screws to bring it down again.  At this stage when I revved it up, there was less black smoke – not gone, but less.   By now, the car had been idling for about a half hour.  It was struggling to stay running.  I had to pull against the throttle cable every 30 or 40 seconds to keep it running.  Also, the exhaust pipe sounded different.  I can only describe it as sounding like it was spitting, if that makes any sense!   So I wondered if I am doing this correctly?  Should I maybe turn both of these jet adjusters all the way in first, and then bring them out a little and try to start the car?  Or should I do it while the car is running;  turn them in until the car starts to struggle?  I don’t really understand why this problem exists when the engine is warm.  When it is cold, it idles fine.   Am I going about this the right way?

Thanks.

 

.....Mick.....

[johny]

Are you confident that everything else is correctly adjusted on the engine: timing, valve clearances, no air leaks, carb float levels, carb airflow balance etc? If so then it seems like the carb fuel mixtures need to be adjusted - the manual explains how to get a basic setting and then do the fine tuning👍 

[Pete Lewis]

remove the air piston and try to measure the depth of the jet in its holder  both should be the same

the std base setting is adjust to level the jet with the bridge and wind down 3 full turns   as a base starting point 

adjust to get the fastest idle in 1/4 turn increments    do both carbs the same 

to set the balance  loosen the joining rod clamp  turn idle screw to just touch its casting    turn in 1.5 turns  nip up the rod claps  and both throttles are now set mechanically to the same point 

Pete

[micmak]

Johny; 

Well, no!   I am not particularly confident of anything.  I bought the car a few months ago, and I have only done 350 miles in it.  I bought it as a “restored” car.  It all looks nice and new and well restored.  But I really have no idea what exactly was done during the restoration. I will make a big assumption that the engine timing valve clearances etc, are all ok.  But I really don’t know for sure.  I am guessing that you would say check all those things first, and then look at the carbs?  If so, would timing or valve clearances explain good running when cold, but bad running when warm?

 

Pete; 

Forgive me, but I will have to consult the manual to try to understand what you are suggesting.  I expect it will become clear enough when I see the diagrams. I will do so over the weekend.

 

Thank you Gents.

[johny]

yes sorry but with any 'new' car its best to systematically work through the whole procedure as then you are 100% sure where you are. Otherwise you can drive yourself nuts trying to sort problems that are caused by something completely different. Many of these things only have to be done once (for a long time anyway) and you can relax knowing that whatever issues arise they arent down to one of those things being wrong.

Your problem does sound like carb mixture adjustment but you wont get it 100% right if theres other things outstanding and when you do finally rectify those you may have to revisit the mixture adjustment again☹️

[Pete Lewis]

this is a vitesse with cd150 carbs  with what i call the thmes barrier type choke so no excess fueling from any of that .... there is little to go wrong here 

cold engine will run fine if set too rich   a hot engine wont goes all wooly and ends up stalled  .

you have found that leaning the adjuster upwards has already increased the idle rpm  so you need to go a bit further

and keep adjusting the jet upwards and get to the best running condition   you only need ears to tell where you are going 

if its improving the rpm then ypu are on the right track  ...just do a bit more 

we can give tips on lifting pin tests but get the basics nearer right first

Pete

[micmak]

That is very encouraging, Pete.  Thank you.  I will take a look at it again tomorrow and try to lean it out more.  I feel empowered by your comments.  I thank you for that!   

Not to take from your comments, Johny.  But I will take the carb route first and see where it takes me.

Thank you both for your suggestions.  I will keep you up to date on my progress.

Thank you, both!

 

.....Mick.....

[micmak]

So today, I decided to further lean out the fuel.  I went out to the car, and it wouldn't start!   Keeping in mind the fact that I DID lean it out a little the other day, I decided to give it full choke, which I have never done before.  It still wouldn't start.  I lifted the lid, and there was fuel dripping onto the floor.  I removed the air filter housing, and BOTH carbs were dripping fuel, not just the LHS like before.  How can there be too much fuel now after partially leaning it out the other day?  OK, so the choke gave it too much, perhaps, but why wouldn’t it start with just a little choke like normal?