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Wailing Bosch Pump


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I have to be honest and say I run with normal most times.

How is pump temperature when running, if a Bosch pump is hot its normally due to having trouble getting enough fuel.

Good luck. Now if you need or want to change the pump I have a large list of compatibles and there are a lot of non Bosch supstitutes on the market for very small sums now.

T

If you have a list, could it be published in some way??

May help all round?

 

Thanks

 

John

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John I did in the thread only a few weeks ago, It was a long thread where I also linked to some probable very cheap alternatives to Bosch, you can check in the past stuff. If not give me the number off the pump and I will tell you the equivalents.

T

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It sounds like the classical harmonic resonance issue and unlikely to be a fault with any of the components as is confirmed by it running fine.

 

Sometimes with a Bosch pump the resonant frequency in the pressure side is set off by the movement of the PRV which acts like the reed in a wind instrument.

 

Sometimes changing the pressure helps, sometimes simply loosening and twisting a flexi pipe will do the trick as can changing the length of the flexi pipe to the PRV.

 

Not come across it happening with the diaphragm type prvs as they don' seem to resonate at the right frequency to set up a resonance (or at least not in the audible frequencies)

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I seemed to have stopped my Bosch pump wailing with a proper CAV filter, the one I took off was from Moss. I took the filter apart, it wasn't dirty, but seemed to have much less paper and thicker construction. I was going to do a flow test through it, but got carried away when I took it off and opened it up see what was inside, anyway the new one seems to be working much better.

John

Hi John! In the days of Lucas, there was one type of filter for petrol and another type for diesel? They had difference part nos. ! I do not know what the difference was? Which one have you got? Moss may not be buying the right one? which would not be a surprise to me! Halfords used to offer the correct one.

 

Bruce

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My Bosch pump started a high pitch whine, or more accurately a very loud squeal, as I arrived home this afternoon. It might have been the same sound as with this thread.

 

The car ran fine for the couple of hundred metres to home. I turned the ignition off, restarted it straight away and no squeal.

 

The car was fitted with a Bosch pump before I bought it nearly 2 years ago. The car has only done about 60,000 miles all up and only 10,000 in the last 20 years so the pump isn't very old. There has been no change to the fuel system for 12-15 months and about 4000km of driving.

 

I checked the filters etc and all is clear, no leaks and fuel is flowing normally. The tank is 3/4 full with 98 octane.

 

I took it for a 5km test drive which included a hard run to 4500rpm in 2nd, cruised at 70km/h and idled at lights. No dramas at all.

 

I haven't experienced this one before. Anybody else had a Bosch pump start squealing and then come good when the ignition is turned off?

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Bruce

I went to a Massey Ferguson dealer and bought their 296 filter, a genuine one. I know its for diesels, but now problem at all so far.

When looking at the construction it is much better than the moss one and does seem to have stopped mine whining.

As I said I was going to do a flow test, take off the pipe to the pump and just let it run thru and measure and time it, then put in the CAV filter and compare the difference.

I got carried away when I took off the old one I opened it to see what was inside, and then realised what I had done, but the new one seems to be working well!

John

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The pump squels when its lacking fuel, like when you corner hard in a TR5 and the fuel runs dry a second. rather than actual fuel not reaching pump its just a drop in feed pressure. My guess is its a lack of fuel flow.

Where is pump?

Which Bosch pump is it? (part number stamped on it)

How much hose do you have feeding it?

Tony

 

 

My Bosch pump started a high pitch whine, or more accurately a very loud squeal, as I arrived home this afternoon. It might have been the same sound as with this thread.

 

The car ran fine for the couple of hundred metres to home. I turned the ignition off, restarted it straight away and no squeal.

 

The car was fitted with a Bosch pump before I bought it nearly 2 years ago. The car has only done about 60,000 miles all up and only 10,000 in the last 20 years so the pump isn't very old. There has been no change to the fuel system for 12-15 months and about 4000km of driving.

 

I checked the filters etc and all is clear, no leaks and fuel is flowing normally. The tank is 3/4 full with 98 octane.

 

I took it for a 5km test drive which included a hard run to 4500rpm in 2nd, cruised at 70km/h and idled at lights. No dramas at all.

 

I haven't experienced this one before. Anybody else had a Bosch pump start squealing and then come good when the ignition is turned off?

Edited by Rem18
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Longer hose now fitted (Moss part no. TGK 1255) and pump is now a lot quieter (it was louder than the exhaust). Hose supplied with the Bosch pump/filter assembly connecting pump to PRV is now fitted from tank to filter assy, although the banjo fitting had to be changed as it is too small, I wouldn't have thought that the bosch conversion used 2 different sizes of banjo fitting, but there you go!

 

Many thanks to all replies to my problem, especially Rem 18.

Graham.

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Heh Graham Thanks for the call out. I am famous but there are people far more expert than me here...hahahahaha.

If anybody needs to compare pump info please look up the thread from about 6 weeks ago or if not call out I have a pretty good list of pump references now, it need not be a £300 conversion...

Best Tony

Longer hose now fitted (Moss part no. TGK 1255) and pump is now a lot quieter (it was louder than the exhaust). Hose supplied with the Bosch pump/filter assembly connecting pump to PRV is now fitted from tank to filter assy, although the banjo fitting had to be changed as it is too small, I wouldn't have thought that the bosch conversion used 2 different sizes of banjo fitting, but there you go!

 

Many thanks to all replies to my problem, especially Rem 18.

Graham.

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Am I correct in stating that Bosch dont make a suitable fuel pump for the TR6 anymore... The prestige site suggest this and he says the pump in his conversion is a suitable alternative to the same spec...I wonder who makes the pump?

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I have been looking at fuel systems on modern cars and noticed that Mercedes,BMW,Rolls Royce all use a fuel accumulator. I have never seen anyone mention using a fuel accumulator for TR6 PI - is there a good reason for this? The following is a description from Bosch

 

Fuel Accumulator

The fuel accumulator maintains the pressure in the fuel system for a certain time after the engine has been switched off. When the engine is running it serves to deaden the noise of the electric fuel pump. After the engine has been switched off, the fuel accumulator maintains the pressure in the fuel system in order to facilitate re-starting, particularly when the engine is hot. The design of the accumulator housing is such that it deadens the noise from the fuel pump when the engine is running. The interior of the fuel accumulator is divided into two chambers by means of a diaphragm. One chamber serves as the accumulator volume for the fuel, the other chamber contains a spring. During operation the accumulator chamber is filled with fuel. This causes the diaphragm to bend back against the force of the spring until it is halted by the stops in the spring chamber. The diaphragm remains in this position, which corresponds to the maximum accumulator volume, as long as the engine is running. When the engine is shut off the spring chamber holds pressure in the fuel system.

 

This seems to be the perfect solution to noisy pumps and difficult starting on TR6 PI wouldn't you say??? Interested to hear what people say regards this.

 

Michael

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Given the design of the Lucas mechanical system I would think any pressure stored in the accumulator would dissipate through whatever injector was being pointed at by the MU when the engine stopped. At least down to the blow off pressure of the injector.

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Am I correct in stating that Bosch dont make a suitable fuel pump for the TR6 anymore... The prestige site suggest this and he says the pump in his conversion is a suitable alternative to the same spec...I wonder who makes the pump?

There appear to still be retailers advertising the Bosch pump we need (8bar output).

The issue is, they want about £500 for them! :(

 

 

I have been looking at fuel systems on modern cars and noticed that Mercedes,BMW,Rolls Royce all use a fuel accumulator. I have never seen anyone mention using a fuel accumulator for TR6 PI - is there a good reason for this? The following is a description from Bosch

 

Fuel Accumulator

The fuel accumulator maintains the pressure in the fuel system for a certain time after the engine has been switched off. When the engine is running it serves to deaden the noise of the electric fuel pump. After the engine has been switched off, the fuel accumulator maintains the pressure in the fuel system in order to facilitate re-starting, particularly when the engine is hot. The design of the accumulator housing is such that it deadens the noise from the fuel pump when the engine is running. The interior of the fuel accumulator is divided into two chambers by means of a diaphragm. One chamber serves as the accumulator volume for the fuel, the other chamber contains a spring. During operation the accumulator chamber is filled with fuel. This causes the diaphragm to bend back against the force of the spring until it is halted by the stops in the spring chamber. The diaphragm remains in this position, which corresponds to the maximum accumulator volume, as long as the engine is running. When the engine is shut off the spring chamber holds pressure in the fuel system.

 

This seems to be the perfect solution to noisy pumps and difficult starting on TR6 PI wouldn't you say??? Interested to hear what people say regards this.

 

Michael

Hi Michael

Part of the scenario that needs to be factored into the 'accumulator' mechanism is the pressure we (Mechanical PI) users need (@ 8Bar) compared to many 'modern' EFI users at (I think @3-4 Bar), and the fact that their 'MUs' and injectors are a little more 'sohisticated' too.

 

It would be nice if all this info was collated somewhere, so we could determine how/what to buy/try rather than expend ages (and £££) experimenting!! :wacko: :wacko:

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I looked at installing an accumulator from a Volvo Jetronic system a few years ago, the idea of maintaining pressure in the PI system seemed attractive to allow quicker starts . The Volvo accumulator I was considering is detailed here:

 

https://www.google.com.au/url?sa=t&rct=j&q=&esrc=s&source=web&cd=7&cad=rja&uact=8&ved=0ahUKEwiY57aZhMnbAhVElJQKHYLfB3EQFgg3MAY&url=https%3A%2F%2Fwww.volvoclub.org.uk%2Ftech%2Ffuel_injection%2FBoschMechanicalFuelInjection.pdf&usg=AOvVaw2TTG179Ms62kWgrpzqPQP6

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An advantage may be you keep the fuel pressure above its bouiling point, thus avoiding vapor belks developing, assuming the fuel pressure will reduce from 105 to approx. 50 psi (the opening pressure of the injectors I believe) once the pump is switched of.

This is assuming there are no leakages, which there are, probably.

 

A disadvantage is that if an injector is leaking, the accumulated fuel in the accumulator will leak to the cylinder.

Waldi

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Good reference Mike C.

I do think that some suppliers try to create an air of mystery around fitting a Bosch system.
Bosh standardised a lot of pumps.
If anyone wants a list of the pumps that will fit a PI I can re publish some links or better still leave your pump numbers here and you can then get info regards these.
I have this info.
Also there are very many non Bosch pumps on the market. Some at very low prices that could be worth a try.
Tony

Edited by Rem18
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I have a non TR race spec car with Jetronic.

The principle is very straight forward.

Facet style pump to aluminum swirl tank which also has a return to tank for excess fuel.

This feeds Bosch filter then on to Bosch pump and then on to non return accumulator to injector rail.

However as others have stated if you have any pressure leak in your system (and you probably will) then it will drop anyway.

But an accumulator would get you back up to pressure quickly I think.

Tony

 

I looked at installing an accumulator from a Volvo Jetronic system a few years ago, the idea of maintaining pressure in the PI system seemed attractive to allow quicker starts . The Volvo accumulator I was considering is detailed here:

 

https://www.google.com.au/url?sa=t&rct=j&q=&esrc=s&source=web&cd=7&cad=rja&uact=8&ved=0ahUKEwiY57aZhMnbAhVElJQKHYLfB3EQFgg3MAY&url=https%3A%2F%2Fwww.volvoclub.org.uk%2Ftech%2Ffuel_injection%2FBoschMechanicalFuelInjection.pdf&usg=AOvVaw2TTG179Ms62kWgrpzqPQP6

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I think one issue is that the Bosch pump is common with an old 911 Porsche. This means people will pay a lot for these. I was lucky enough to pick up a spare for a low price a while back.

Cheers

Tim

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Tim there is more than one pump.

And as I said there are a lot of non Bosch with same spec in theory.

I dont really see why people are worrying so much.

The PI system is not a black hole.

These were cars built by Triumph not NASA.

Edited by Rem18
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Here is the thread I started a while back.

You can find just about all the info you need on the fuel pumps.

So as not to hijack this thread.

Just reply to the thread if you have any questions and it should come back up in the new content.

Tony

https://www.tr-register.co.uk/forums/index.php?/topic/65781-funny-fuel-stories-the-inevitable-pump-saga/

Edited by Rem18
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Yes I know they are more than one. The one i run is either the 909 or 910.

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909 and 910 should be Ok obviously factors like if you are using a CAV or Bosch pump count too.

Tim please take a look at the old thread I linked and if you have any questions feel free to ask.

https://www.tr-register.co.uk/forums/index.php?/topic/65781-funny-fuel-stories-the-inevitable-pump-saga/

Tony

 

Yes I know they are more than one. The one i run is either the 909 or 910.

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