Petrol leak from front

clive P62

clive P62

Active Member
I fully overhauled my friends HIF carbs on his V8 auto a few months ago but he has noticed a fuel smell and poor running recently.
Had a look and one carb flooding badly.
All new so called genuine S/U parts.
Didn't expect to find this though.
Have had some issues with rubber tipped needle valves but not floats.
Clive.

20170319_142725.jpg
 
It used to be a problem back in the day, I changed loads, but you'd hope things would be better now. Some hope!
 
It was a good job I don't throw away old/ serviceable floats!
I had to obtain 2 old type spring loaded brass needle valves to replace the much larger vitron tipped ones on a 2200 T/C because of persistent flooding problems.
 
I always appreciated the old brass floats of yesteryear, they were a sculpture in their own right, beautiful, sometimes soldered where 2 half's joined and so delicate, but lasted a lifetime if cared for gently....
my BSA Bantam had one and my brothers Austin 7.................ahhh .........end of rant :rolleyes:
Peter
 
hmm thats interesting. I've bene having issues with stumbling idling and cutting out at lights.. replaced everything electrical .fuel filter etc new full electronic dizzy even. put a small extra return spring on carbs in case it wasn't settling back correctly.
took a drive to the Naze at walton and back. cutting out at lights, hesitation when driving at same speed and loss of power, had to use choke during driving and was only good when accelerating. even then initial pull away had a 2 second delay before responding to throttle. ( one of the joys of P6 ownership is I think continued issues lol)
anyway .pulled up at home on drive. jump out and opened gates .lo...it cut out . however as I was out of car and looking back at it .I noticed petrol pouring onto floor. overflow form carb(s) .restarted .drove into garage and shut off. checked and again fuel washing floor! so I am assuming both carbs are having flooding issues . (wet both sides of engine) both were refurbed with carb kit from Wins using the rubber tips. approx 18 months ago. so question I seem to be asking self is. do I buy another kit? have an expert carb full overhaul ( ££££) which won't go down well with other half ( planning on killing me I think for chucking so much money at damn thing)
or... should I swap out fuel lift pump and use electric? the fuel pump was also overhauled same time as carbs. won't be taking it back on roads anytime soon ( another sore point with wife) until I can stop flooding issues .
 
A fault most likely in the manufacture. I had a similar experience with a new float some 10 years ago following the installation of my 4.6. I had rebuilt both carburettors in readiness, and whilst one failed and required replacement only weeks later, the other remains without having given any issues thus far.

Ron.
 
Clive, I not sure what you are showing in the photo, has the float filled with fuel?

I'd only carb parts from Burlen at The Worlds Sole Manufacturer of Genuine SU Parts - SU Carburetters this is the only way to know you are getting genuine SU parts. Their on line shop is not always the best for finding the parts you are looking for, a phone call will usually provide the part you need.

Classicalgreen, is your return line clear, a blocked return line could cause over pressure of the fuel supply which will push the valve open raising the fuel level.

Gavin.
 
I wonder has anyone actually put a fuel pressure gauge on their car to check the pump output ? I did because I installed an electric pump and found that the SU HIF6 would not tolerate any more than 3 psi so set my pressure just under.
It may be the mechanical pump fitted with a modern rebuild kit is producing more pressure than the carbs can handle therefore leading to flooding. Just a thought.
 
You could be right Mark but I had a never ending flooding issues with my mates 2200 T/C with original mechanical pump and these don't have a return system, only cured by replacing the vitron tipped needle valves with old type spring loaded brass type.
Clive.
 
I cannot remember what I ended up with now needle wise, I know I ordered new viton needles but may have reverted to brass. I sure am not going to disturb them again to look :eek:
 
I had terrible trouble with modern needle valves. eventually sorted by adjusting the floats. If I remember I had put the steel rule with the carb on its side and not upside down as the weight of the float a was closing the valve where the floats when floating wouldnt quite have the same force.

I dont think stay up® float are available for our carbs yet.

colin
 
clive P62 said:
You could be right Mark but I had a never ending flooding issues with my mates 2200 T/C with original mechanical pump and these don't have a return system, only cured by replacing the vitron tipped needle valves with old type spring loaded brass type.
Clive.
Click to expand...

Afternoon Clive
My 1975 V8 auto has just developed the same fault ( HIF6 of course) with fuel being dumped through the overflow.
It's the drivers side carb' and it literally happened when returning home from a 30 mile round trip yesterday. Didn't show any sign of hesitation or rough running prior to this. completed a 200 mile round trip on Saturday and it ran beautifully. Only had the engine rebuilt last year by Colin Gould including a rolling road session; and I have to say the car was transformed and ran as well as ever in the 24 years I've owned it. It's now covered 1300 miles since the rebuild, so I'm a bit disappointed to find an issue like this but reading the posts from several others including yourself, I'm not alone !!
I had no idea that the needle valves had changed over the years though - you mention spring loaded brass types and I guess I can still buy these from SU parts suppliers?
I'm no mechanic but would be willing to have a go and try and fix the problem and try to understand the complexities of said carb'; looking under the bonnet with air filter removed, not sure where to start first, so any tips would be very useful. Burlen appear to be the company to go to unless you use another supplier?
Had my first V8 back in 1982 - another 1975 auto and ran it for 3 years as my daily driver and never had a carb issue like this.

Anyway enough rambling, thanks

Rowan
 
Hi Rowan.
You would need to remove the flooding carb and remove the lower float cover { 4 screws } and check the float which would be easy to see if it was full of fuel. If ok then check the needle valve for any dirt / contaminates.
Chances are the valves are vitron type and are the only type now supplied by Burlen { even though i got the brass ones from them!}
Recheck float level again using the workshop manual first, but there are posts on here to set it as well .
Refit and retest.
Clive.
 
Beware, as soon as you remove the cover the thin 'o' ring gasket will expand so much that you will not be able to re fit it.
So best get gaskets first ;)
 
had an old school mechanic look at my car when on show at plough corner. said it was common issue on old rovers in his day when dirt got stuck on needle /valve. leading to flooding etc . he saw my inline filter was Ok and as no more flooding since? the 'dirt' may have moved off.. hopefully. don't think return line is blocked . was all clear when all pipes checked when tank was removed an lines blown through.
 
Evening Clive, cobraboy, classicalgreen
Many thanks for the comments/tips.
Had another look tonight and having studied the Burlen site and taken some photos of linkages etc, I'll contact Burlen tomorrow and purchase the required parts.

Cheers

Rowan
 
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