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Paul Hill

Bosch pump woes

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My pump as been performing well of late, we went on a good run yesterday 130 miles round trip with the last 35 miles very spirited on twisty turny roads. When we were nearly home we encountered some standing traffic and the pump seemed to be revving, it had no effect on performance but not heard it like that. The pump is wired separately and about  8 months old. There is not a pre pump filter as I can see, and the tank is the original. Turn the ignition on and listen at the filler cap and good healthy return to the tank. The pump is in the boot

My question is anyone know of an expert local to me in Staffordshire or West MIdlands where I can get it sorted once and for all

 

many thanks Paul

 

 

 

Edited by Paul Hill

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Will do Rob thanks for that

 

Paul

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16 hours ago, Paul Hill said:

My pump as been performing well of late, we went on a good run yesterday 130 miles round trip with the last 35 miles very spirited on twisty turny roads. When we were nearly home we encountered some standing traffic and the pump seemed to be revving, it had no effect on performance but not heard it like that. The pump is wired separately and about  8 months old. There is not a pre pump filter as I can see, and the tank is the original. Turn the ignition on and listen at the filler cap and good healthy return to the tank. The pump is in the boot

My question is anyone know of an expert local to me in Staffordshire or West MIdlands where I can get it sorted once and for all

 

many thanks Paul

 

 

 

If your tank was below 1/4 it was probably the pump cavitating. Mine does it, car still runs ok but very loud pump noise.

Fill it up and all is good.

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18 hours ago, Paul Hill said:

My pump as been performing well of late, we went on a good run yesterday 130 miles round trip with the last 35 miles very spirited on twisty turny roads. When we were nearly home we encountered some standing traffic and the pump seemed to be revving, it had no effect on performance but not heard it like that. The pump is wired separately and about  8 months old. There is not a pre pump filter as I can see, and the tank is the original. Turn the ignition on and listen at the filler cap and good healthy return to the tank. The pump is in the boot

My question is anyone know of an expert local to me in Staffordshire or West MIdlands where I can get it sorted once and for all

 

many thanks Paul

 

 

 

Hi Paul,

I think you may have had cavitation problems?

How full was your tank, if it was low below 1/4 you can still get the symptoms of cavitation as one got with the Lucas pump. Also what is the bore size of your pipework from tank to pump the original 1/4" bore will not give the correct flow rate to a  genuine Bosch pump, it has to be 8 m/m minimum. Mine is 10m/m! Small size restrictive pipe work can also cause semi cavitation symptoms.

Bruce. 

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The pipe work is 10mm so should be ok and the tank is over half full. I am starting to think it may be some debris in the outlet of the tank.

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4 minutes ago, Paul Hill said:

The pipe work is 10mm so should be ok and the tank is over half full. I am starting to think it may be some debris in the outlet of the tank.

Have you checked fuel line pressure at the M/U?

Bruce.

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Hi Bruce 

just to add I now have the angry bee noise but not to loud, the bottom cylinder on the pump is where the noise is and it’s getting warm after about 4 miles just took her out before the rain came. 

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Hi Paul,

if you have 10 mm inside diameter hose from tank to pump and no suction filter and no sharp bends in the hose (that will reduce the ID), you should not have cavitation, certainly with a half full tank.

I suggest to use a hose clamp to pinch the hose, disconnect hose from pump, and see how well it flows (there is a hole in the bottom of the boot, you can stick the hose trough in a large enough container. It should give a large flow, like 5 liter/min (the Bosch pump can pump around 3-4 liter/min).

When I bought my TR6 I had a blocked tank outlet (too), and my pump was screaming.

Regards,

Waldi

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Hi Paul,

Could also be the same problem as I have. I have a blockage inside the fuel tank so the fuel return from the PRV is not going anywhere. I disconnected the hose at the top of the tank and ran into a container, no screaming or hot pump.

Cheers.

Mark.

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On 9/23/2019 at 9:41 AM, astontr6 said:

Hi Paul,

I think you may have had cavitation problems?

How full was your tank, if it was low below 1/4 you can still get the symptoms of cavitation as one got with the Lucas pump. Also what is the bore size of your pipework from tank to pump the original 1/4" bore will not give the correct flow rate to a  genuine Bosch pump, it has to be 8 m/m minimum. Mine is 10m/m! Small size restrictive pipe work can also cause semi cavitation symptoms.

Bruce. 

Hi Bruce,

As you say the standard tank outlet pipe in 6mm.

please explain how to modify to 8 or 10mm?

Peter

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29 minutes ago, Peter V W said:

Hi Bruce,

As you say the standard tank outlet pipe in 6mm.

please explain how to modify to 8 or 10mm?

Peter

You can Buy the bigger 8mm Outlet but how you get to 10mm I’d like to know also.

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3 hours ago, Mark Ogram said:

Hi Paul,

Could also be the same problem as I have. I have a blockage inside the fuel tank so the fuel return from the PRV is not going anywhere. I disconnected the hose at the top of the tank and ran into a container, no screaming or hot pump.

Cheers.

Mark.

Hi Mark

i am almost certain it **** in the tank again, the symptoms point that way so I am thinking of swapping it for a new Alloy tank. I did have a old seal from a leaded addative bottle that was in and wrapped itself round the outlet, the pump made a terrible racket

Edited by Paul Hill

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If you buy a new tank make sure it has the design  features required to overcome as many of your potential fuel problems as possible. For example my alloy tank has the return line fitted on the far side of the tank from the pump suction line- above the passenger side rear wheel. That means that heated fuel has to cross the tank before returning to the pump suction - helps feed the pump cooler fuel- minimizing cavitation , which is important on a hot day in Australia. 

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The people who manufacture the alloy tanks are only one mile from my home, and will go see them to make sure.

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21 hours ago, TR NIALL said:

You can Buy the bigger 8mm Outlet but how you get to 10mm I’d like to know also.

Years ago where I worked there was a company next to ours that made all types of fuel tanks mainly for industrial applications. As I had had a lot of trouble with my Lucas pump and bosch pumps were starting to be used as an alternative. I phone bosch's technical dept. to find out what pump of there's would do the job. By chance the engineer that I spoke to had a TR6 with a bosch pump. So I was given the full spec of a Merc diesel pump that was required, could pump to 150 psi and 8mm bore size was the minimum but you could go as high as 12mm. Based upon info received I went to the tank company next door and they flooded my tank with argon gas and drilled out the take off hole. I also went into our toolroom and had a brass adaptor turned up to suit. That was over 40 years ago!

Bruce.

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On 9/23/2019 at 4:32 PM, Paul Hill said:

Hi Bruce 

just to add I now have the angry bee noise but not to loud, the bottom cylinder on the pump is where the noise is and it’s getting warm after about 4 miles just took her out before the rain came. 

My suspicions are that you have some form of the dreaded harmonic hammering caused by using a solid smooth bore PTFE hose rated at 1000 psi  or similar sold by some of the so called PI experts in the UK. They now sell diaphragm PRV's to combat this????? I am still using the old Lucas type and have had no problems, as I use the correct rubber hose!

Bruce.

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27 minutes ago, astontr6 said:

Years ago where I worked there was a company next to ours that made all types of fuel tanks mainly for industrial applications. As I had had a lot of trouble with my Lucas pump and bosch pumps were starting to be used as an alternative. I phone bosch's technical dept. to find out what pump of there's would do the job. By chance the engineer that I spoke to had a TR6 with a bosch pump. So I was given the full spec of a Merc diesel pump that was required, could pump to 150 psi and 8mm bore size was the minimum but you could go as high as 12mm. Based upon info received I went to the tank company next door and they flooded my tank with argon gas and drilled out the take off hole. I also went into our toolroom and had a brass adaptor turned up to suit. That was over 40 years ago!

Bruce.

Thanks Bruce I was thinking that that was the only way to do it,Cheers.

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On 9/25/2019 at 10:55 AM, astontr6 said:

My suspicions are that you have some form of the dreaded harmonic hammering caused by using a solid smooth bore PTFE hose rated at 1000 psi  or similar sold by some of the so called PI experts in the UK. They now sell diaphragm PRV's to combat this????? I am still using the old Lucas type and have had no problems, as I use the correct rubber hose!

Bruce.

The sound of a jet engine just behind your L ear is pretty intrusive.

It isn't exclusive to the braided hoses - can also happen with the rubber ones too particularly as they get stiffer with age.  A simple test is to move the pipe a bit by pushing it or bending with your hand - if the sound goes away then it is conclusive. Try cracking the union and moving the angle of the pipe - it can work but you may need to replace the pipe.

If it's not the harmonics:

Other than debris restricting the flow other things can be a clogged pre-filter if fitted or a collapsing pipe. (Whilst larger bore tank outlets are optimal it is an utter myth that they are essential so don't rush into sorting this one - it's something you do when you have the tank out for another reason or when replacing a rusty tank)

A stuck PRV can make the pump sound like you have a small motorbike revving in the boot - the Bosch pumps can deliver up to 150psi but that isn't good for the metering unit.

 

 

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1 hour ago, Andy Moltu said:

The sound of a jet engine just behind your L ear is pretty intrusive.

It isn't exclusive to the braided hoses - can also happen with the rubber ones too particularly as they get stiffer with age.  A simple test is to move the pipe a bit by pushing it or bending with your hand - if the sound goes away then it is conclusive. Try cracking the union and moving the angle of the pipe - it can work but you may need to replace the pipe.

If it's not the harmonics:

Other than debris restricting the flow other things can be a clogged pre-filter if fitted or a collapsing pipe. (Whilst larger bore tank outlets are optimal it is an utter myth that they are essential so don't rush into sorting this one - it's something you do when you have the tank out for another reason or when replacing a rusty tank)

A stuck PRV can make the pump sound like you have a small motorbike revving in the boot - the Bosch pumps can deliver up to 150psi but that isn't good for the metering unit.

 

 

Hi Andy,

The key issue is the PSI rating of the hose. In my experience when you go above 300 PSI then you can get the harmonic hammering. My hose at present is rated at 220 PSI and therefore is very flexible, with out s/s braid and has never hammered. My gripe is with the supply of 1000 PSI smooth bore PTFE S/S hose  where you will definitely will get the hammering and then to cure that problem you have to buy one of his diaphragm PRVs and he is meant to be the DB of PI systems. I have had this discussion with him at one of the internationals. You can use a PTFE hose but it must be, the convoluted type and not smooth bore. The convoluted type breaks up the pulsing action from the pump and this is what causes the valve to hammer on its PRV seat. Regarding the 150PSI that my pump can go to ! As the fuel line pressure is governed by the PRV that is in material. Regarding flowrate to a bosch pump. As quoted in 1985 by Bosch UK Eng. Dept. The minimum flow rate( flood feed) to the pump must be 2.6 litres per minute. You will not get that through a 1/4" bore pipe?? So I do not see that as a myth! Remember during my apprenticeship I worked at CAV for 1 month on an exchange scheme and Lucas were playing with the idea of increasing the bore pipework size to 5/16" to combat cavitation from the Lucas pump and a change of fittings into the filter head. They had worked out that the Lucas pump needed a better flow rate from the tank.

Bruce.

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I didn't suggest the pipe was the cause of 150 psi - I said I had seen Bosch pumps deliver  in excess of 150 psi when the PRV was seized. This can cause the pump to make some strange noises when trying to deliver this pressure.

Similarly the harmonic resonance is not exclusive to braided pipe - it can happen with the original spec but is more likely with some of the braided hoses.

For 30+ years TR6s have been running Bosch pumps happily on the standard tank outlet and whilst Bosch may well have specified a higher flow rate for their pumps to work optimally (and they probably hadn't got the Lucas PI system on their consideration list then) they will run pretty well nevertheless.

The "Injection specialist" who was one of the proponents larger tank outflow for the users of Bosch pumps in TRs overlooked that the kit he was selling with this included a glass pre-filter that had an internal bore diameter significantly smaller than the pipework fitted as standard.
A larger outflow from the tank is optimal - not disputing that.

There were a number of reasons that the Lucas Pumps suffered with cavitation - the largest of which, I was reliably informed by the person whose job it was to control the costs, was the need to supply the entire injection system that Triumph could afford to fit to their cars which compromised the pump that Lucas wanted to fit which was higher spec and powered by a different motor. What could be afforded was a puny pump powered by a wiper motor that was marginal at best when in optimum condition. Move on 50 years and the tanks and pipes are full of crud, fuel different, pumps worn and the climate hotter....

 

 

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20 hours ago, Andy Moltu said:

I didn't suggest the pipe was the cause of 150 psi - I said I had seen Bosch pumps deliver  in excess of 150 psi when the PRV was seized. This can cause the pump to make some strange noises when trying to deliver this pressure.

Similarly the harmonic resonance is not exclusive to braided pipe - it can happen with the original spec but is more likely with some of the braided hoses.

For 30+ years TR6s have been running Bosch pumps happily on the standard tank outlet and whilst Bosch may well have specified a higher flow rate for their pumps to work optimally (and they probably hadn't got the Lucas PI system on their consideration list then) they will run pretty well nevertheless.

The "Injection specialist" who was one of the proponents larger tank outflow for the users of Bosch pumps in TRs overlooked that the kit he was selling with this included a glass pre-filter that had an internal bore diameter significantly smaller than the pipework fitted as standard.
A larger outflow from the tank is optimal - not disputing that.

There were a number of reasons that the Lucas Pumps suffered with cavitation - the largest of which, I was reliably informed by the person whose job it was to control the costs, was the need to supply the entire injection system that Triumph could afford to fit to their cars which compromised the pump that Lucas wanted to fit which was higher spec and powered by a different motor. What could be afforded was a puny pump powered by a wiper motor that was marginal at best when in optimum condition. Move on 50 years and the tanks and pipes are full of crud, fuel different, pumps worn and the climate hotter....

 

 

A key point that I missed out was that the Bosch 150 psi pumps also have an advantage that it can supply the fuel line pressure required at a much lower running current than some of the other Bosch pumps used in this application i.e. 6 amps and none of this 15 amp business. I have to agree with you regarding those glass filters, I have only ever used bosch or mahle filters which require rather large pipe fittings, some of which were turned up by a friend of mine. They are also low flow resistance filters. All my metal pipework/ fittings are over 35 years old. The rubber hoses are Gates Barricade which can resist up to 85% ethanol. The only trouble is Gates UK do not import this hose into the UK. My hose came directly from the USA. 

Bruce.

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Hi Bruce,

I am not familiar with a Bosch pump only requiring 6A @105 psi. Do you know the part number. My new Bosch pump which I selected from a Bosch pump datasheet draws 10-12A, if I recall correctly, and this was the best possible option ( all pumps in that datasheet supplied much more fuel then needed for a TR6, hence resulting in higher current draw and energy dissipation.

Thanks,

Waldi

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2 hours ago, Waldi said:

Hi Bruce,

I am not familiar with a Bosch pump only requiring 6A @105 psi. Do you know the part number. My new Bosch pump which I selected from a Bosch pump datasheet draws 10-12A, if I recall correctly, and this was the best possible option ( all pumps in that datasheet supplied much more fuel then needed for a TR6, hence resulting in higher current draw and energy dissipation.

Thanks,

Waldi

Hi Waldi,

               The bosch pump that I use has a part number of :0 580 254 952. I was told that these pumps are still made but on a 26 week delivery if out of stock and the other thing you have to watch out for is that they can have 2 types of electrical connections----- screw or socket. I only replaced my original one as it was 35 years old and I was going to do the EC500 in Scotland which was just short of 2000 miles for me, in 2018.

Bruce

 

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Thanks Bruce,

I looked it up, the Bosch datasheet for this pump indicates it draws almost 9A @ 105 psi and delivers around 125 l/hr at this pressure. It is a good selection, and still draws less current than most other Bosch pumps for our cars.

Best regards,

Waldi

 

Edit: I have the 0580.464.126 pump (which replaced a leaking xx996 pump) which draws more amps, approx. 10A according to the datasheet, so the xx952 you have is the better option.

 

 

Edited by Waldi

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