Fuel vapourisation
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rovermorris999
New Member
The only surefire way I know is to fit an electric fuel pump. I must be lucky, none of the V8s I've ever owned have suffered from it.
JohnGlinn(Cardiff)
New Member
I think that ther must be a lot of luck involved with fuel vapourisation - Having run Rover 3500 autos from 1983 to 2000 as an everday car all thro' the year and in all traffic conditions, I can honestly say that it only became a problem once (whilst my wife was driving) and after two calls and nearly three hours waiting for the RAC man (their Cardiff office was 5 minutes away!) I left work walked to where she was broken down, disconnected the fuel lines, pumped new fuel thro' by operating the starter, re-connected and drove home. Needless to say we are no longer RAC members!
Most people that I have spoken to that have suffered from fuel vapourisation swear by the electric fuel pump!
Regards, John.
Most people that I have spoken to that have suffered from fuel vapourisation swear by the electric fuel pump!
Regards, John.
I had this problem on a 3.5S I owned about 10 years ago. It first happened on the night I bought it as I was on the way home. The second time it locked I was out with my other half and kids. After that a friend of mine said the cure was to rebuild the petrol pump which he did and it never happened again.
Rumblin_Ron
New Member
There's been much talk about fuel vaporisation, but I don't think it is a inevitable condition.
I can honestly say that Ron (V8) has never suffered in 4 years of ownership. Even last year when stuck in a motorway for 2 houres in the high 20 Celcius, cars were spouting steam all arround, but Ron did not miss a beat (although the owner did worry greatly).
The only thing done has been to wrap the exhaust manifolds in that insulating bandage stuff, this has greatly reduced the underbody temperature (you just have to touch the bonnet to notice !). This presumably leads to cooler fuel and cooler air (more go ?) and less chance of vaporisation.
But again, before the exhaust mods I never suffered problems. I run on Superunleaded by the way.
Possibly the general condition of intake manifold waterways, carbs and pumps on our old cars are to blame, and an electric fula pump is just a workaround ?? (to defend the original Rover design)
Yours
Ron
I can honestly say that Ron (V8) has never suffered in 4 years of ownership. Even last year when stuck in a motorway for 2 houres in the high 20 Celcius, cars were spouting steam all arround, but Ron did not miss a beat (although the owner did worry greatly).
The only thing done has been to wrap the exhaust manifolds in that insulating bandage stuff, this has greatly reduced the underbody temperature (you just have to touch the bonnet to notice !). This presumably leads to cooler fuel and cooler air (more go ?) and less chance of vaporisation.
But again, before the exhaust mods I never suffered problems. I run on Superunleaded by the way.
Possibly the general condition of intake manifold waterways, carbs and pumps on our old cars are to blame, and an electric fula pump is just a workaround ?? (to defend the original Rover design)
Yours
Ron
So I am not the only one to suffer this with the change in weather!
I have an electric pump, I have never been convinced it is really capable of providing enough fuel. It is mounted up front on the inner wing and I still get vapourisation if I am in stop start traffic for about half an hour. I wonder whether the petrol reserve valve is too close to the head, as I have moved all the other petrol lines away from the engine. Hove near far away should it be?
Some people swear by Kenlowe type electric fans to reduce under bonnet temperatures. I am sure they work. but there must be better cheaper fixes out there?
I have an electric pump, I have never been convinced it is really capable of providing enough fuel. It is mounted up front on the inner wing and I still get vapourisation if I am in stop start traffic for about half an hour. I wonder whether the petrol reserve valve is too close to the head, as I have moved all the other petrol lines away from the engine. Hove near far away should it be?
Some people swear by Kenlowe type electric fans to reduce under bonnet temperatures. I am sure they work. but there must be better cheaper fixes out there?
Rumblin_Ron
New Member
From what Timj has just said I thought came to mind.
New (electric) and rebuilt fuel pumps are a common fix, and the obviouse cause is the fuel getting to hot. Presumably, with our cars running a fuel return pipe back to the tank, these pumps are able to keep a good flowin excess of the engines needs, so the recirculating petrol never gets hot enough to vaporise. So my theory is that worn fuel pumps are to blame.
I'm too young to remember new P6's, did they have problems when new ?
New (electric) and rebuilt fuel pumps are a common fix, and the obviouse cause is the fuel getting to hot. Presumably, with our cars running a fuel return pipe back to the tank, these pumps are able to keep a good flowin excess of the engines needs, so the recirculating petrol never gets hot enough to vaporise. So my theory is that worn fuel pumps are to blame.
I'm too young to remember new P6's, did they have problems when new ?
Squashed Nose
New Member
Is that 98 RON Ron?
Have you had the heads modified and/or are you using an additive?
I ask because of the ongoing debate with regards valve seat recession and the fact that Wadhams are charging 650 nickers for unleaded ready heads! Seems astRONomical to me.
By the way, my P5B suffered with fuel vapourisation all those years ago. Somehow I can't imagine that they suffered from new else Rover would have to have come up with a fix pretty sharpish. Worn fuel pumps seems logical.
Shall we all have a fuel pump rebuilding party?
I rebuilt the fuel pump on my old saloon and it made little difference to fuel vaporisation problems although I have to admit they occured mostly when towing a car trailer and sitting in a traffic jam!
Since then on my current car I've fitted an electric fuel pump in the pump boot. It cured the vaporisation and also made the car much easier to start.
My opinion on the unleaded fuel debate is that it's aluminuim head with hardened steel inserts and therefore unleaded is OK. The only problem I had was with pinking on standard unleaded.
Since then on my current car I've fitted an electric fuel pump in the pump boot. It cured the vaporisation and also made the car much easier to start.
My opinion on the unleaded fuel debate is that it's aluminuim head with hardened steel inserts and therefore unleaded is OK. The only problem I had was with pinking on standard unleaded.
rovermorris999
New Member
Fully agree with you, BB. Unleaded is fine if you retard the ignition or use optimax or superunleaded.
I reckon I agree with ron.
I like to put my foot down, and on a long straight accelerating hard ( flat out ) the car "ran out of petrol" a bit with the electric fuel pump, and the fuel return line plumbed in. blocking the fuel return line helped, but did not totally cure it. I guess that this actually makes vapour lock more of a problem as the vapuor cant go back to the tank.
My fuel pump is a little square pacet (facet?) one from Ray weekeley.
Has everyone who has cured fuel vapourisation put a bigger pump in the back of the car, and left the return line flowing?
If they have then the cheapest option seems to be for me to rebuild the old mechanical pump. I notice that Wadhams do large valves for them though. has anyone got any experience of these?
I like to put my foot down, and on a long straight accelerating hard ( flat out ) the car "ran out of petrol" a bit with the electric fuel pump, and the fuel return line plumbed in. blocking the fuel return line helped, but did not totally cure it. I guess that this actually makes vapour lock more of a problem as the vapuor cant go back to the tank.
My fuel pump is a little square pacet (facet?) one from Ray weekeley.
Has everyone who has cured fuel vapourisation put a bigger pump in the back of the car, and left the return line flowing?
If they have then the cheapest option seems to be for me to rebuild the old mechanical pump. I notice that Wadhams do large valves for them though. has anyone got any experience of these?
I disconected the return pipe on mine. I've just got the pump in the rear pumping straight to the carburettor. I was using a weber 500 carb though so not sure whether this appropriate when using SU's. Can't see any problem though as they still have a float chamber and asscoiated valvle etc.
Possibly the return line is there because a mechanical fuel pump doesn't shut off in the same way as an electric pump when the pressure backs up?
Possibly the return line is there because a mechanical fuel pump doesn't shut off in the same way as an electric pump when the pressure backs up?
rovermorris999
New Member
Mine is an electric pump mounted at the rear with the standard SUs fitted. I think the return is blocked off but I'm not 100% sure as the pump was fitted when I bought the car.
I've used both electric and mechanical systems over the years, (on different cars) and have never had vapour lock.
1. My 3500S had a jaguar electric fuel pump mounted under the petrol tank connected into the reserve fuel line with the main line blocked. At the carburettor end I had it going through a "Filter King" pressure regulator. The return feed was left on. Problem was the pump stopped unexpectedly every few years and was in an inconvenient position. Also no reserve tap.
2. I rebuilt the mechanical fuel pump on my 3500 with a kit. This was an easy job. The kit had large valves so I left the small valves that were in the pump in as they looked OK. Problems; none so far, (1 year), even in severe, hot traffic jams. My water pump is new. I could always put a slimline fan in front of the radiator as a backup such is the fear of vapour lock.
The traffic flow round here doesn't accomodate breakdowns so ultra reliability is a real issue for me.
Eric
1. My 3500S had a jaguar electric fuel pump mounted under the petrol tank connected into the reserve fuel line with the main line blocked. At the carburettor end I had it going through a "Filter King" pressure regulator. The return feed was left on. Problem was the pump stopped unexpectedly every few years and was in an inconvenient position. Also no reserve tap.
2. I rebuilt the mechanical fuel pump on my 3500 with a kit. This was an easy job. The kit had large valves so I left the small valves that were in the pump in as they looked OK. Problems; none so far, (1 year), even in severe, hot traffic jams. My water pump is new. I could always put a slimline fan in front of the radiator as a backup such is the fear of vapour lock.
The traffic flow round here doesn't accomodate breakdowns so ultra reliability is a real issue for me.
Eric
Rumblin_Ron
New Member
Hey Squashed nose !
I met him on a Monday and my heart stood still
Da do ron ron ron, da do ron ron
Somebody told me that his name was Bill
Da do ron ron ron, da do ron ron
Yeah, my heart stood still, yeah, his name was Bill
And when he walked me home, da do ron ron ron, da do ron ron
I know what he was thinking when he caught my eye
Da do ron ron ron, da do ron ron
He looked so quiet but, my oh my
Da do ron ron ron, da do ron ron
Yeah, he caught my eye, yeah but my oh my
And when he walked me home, da do ron ron ron, da do ron ron
He picked me at seven and he looked so fine
Da do ron ron ron, da do ron ron
Someday soon I'm gonna make him mine
Da do ron ron ron, da do ron ron
Yeah, he looked so fine, yeah I'll make him mine
And when he walked me home, da do ron ron ron, da do ron ron
Da do ron ron ron, da do ron ron
Da do ron ron ron, da do ron ron
Da do ron ron ron, da do ron ron
Da do ron ron ron, da do ron ron
Da do ron ron ron, da do ron ron
Da do ron ron ron, da do ron ron
Makes me fire on all cylinders
Rumblin Ron.......da do ron ron (98)
I met him on a Monday and my heart stood still
Da do ron ron ron, da do ron ron
Somebody told me that his name was Bill
Da do ron ron ron, da do ron ron
Yeah, my heart stood still, yeah, his name was Bill
And when he walked me home, da do ron ron ron, da do ron ron
I know what he was thinking when he caught my eye
Da do ron ron ron, da do ron ron
He looked so quiet but, my oh my
Da do ron ron ron, da do ron ron
Yeah, he caught my eye, yeah but my oh my
And when he walked me home, da do ron ron ron, da do ron ron
He picked me at seven and he looked so fine
Da do ron ron ron, da do ron ron
Someday soon I'm gonna make him mine
Da do ron ron ron, da do ron ron
Yeah, he looked so fine, yeah I'll make him mine
And when he walked me home, da do ron ron ron, da do ron ron
Da do ron ron ron, da do ron ron
Da do ron ron ron, da do ron ron
Da do ron ron ron, da do ron ron
Da do ron ron ron, da do ron ron
Da do ron ron ron, da do ron ron
Da do ron ron ron, da do ron ron
Makes me fire on all cylinders
Rumblin Ron.......da do ron ron (98)
Rumblin_Ron
New Member
Sensible again
I was always tought that SU float chambers would flood (force the float valve open) if the was not some form of pressure relief, ie the return pipe or on SU pumps that stop start pressure sensor (for a better word). Do these electric pumps people mention have a similar pressure mechanism, or are they just very low pressure ?
I was always tought that SU float chambers would flood (force the float valve open) if the was not some form of pressure relief, ie the return pipe or on SU pumps that stop start pressure sensor (for a better word). Do these electric pumps people mention have a similar pressure mechanism, or are they just very low pressure ?
Squashed Nose
New Member
How can I tell if my fuel pumps got large or small valves ?
Does the repair kit from Wadhams come with a new engine to pump gasket ?
Sorry if I sound thick, but this is the first V8 I've had since
the early eighties and I never had any vapour lock problems with that at all. Oh, if only I could have that one back!
Perhaps someone somewhere knows if it's still about. I can't
remember the full registration but it was : EGA *** K. It
was a 3.5 s and when I had it, it was Mexico brown.
Boxpleat.
Does the repair kit from Wadhams come with a new engine to pump gasket ?
Sorry if I sound thick, but this is the first V8 I've had since
the early eighties and I never had any vapour lock problems with that at all. Oh, if only I could have that one back!
Perhaps someone somewhere knows if it's still about. I can't
remember the full registration but it was : EGA *** K. It
was a 3.5 s and when I had it, it was Mexico brown.
Boxpleat.