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Fuel pressure gauge


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Having an 'in line fuel pressure gauge' made up at the local hydraulic pipe centre (seems a cheap enough tool to have in the tool box for a 'rainy day') & was thinking, do I test the fuel pressure when the engine is at running temperature or doesn't it really matter?

I read somewhere that you need to have the lights on etc at the same time.

 

Your views, as always, very much appreciated.

 

Nick.

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I would test it in absolute worst case conditions. Cold start, all lights on, fan running if you have an override. It should make the book pressure under these conditions and the PRV should then take over to maintain pressure.

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  • 4 weeks later...

Can anyone recommend a decent electronic gauge that has a period looking face? Everything I've seen so far is very "max power". I' m looking to have something permanently plumbed in and readable whilst driving. Also, has anyone found a reasonably priced T piece for fitting? Thanks

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Hi Nick,

I have a Lucas fuel pressure test kit and I tested the fuel pressure last week the readings were engine not running 7.3 bar engine running 7.5 bar. These are approx 106 psi and 109 psi which are both in the brown book guideline.

 

Parker Hydraulics in Norwich supplied me with 08bp060606 3/8 bsp M/F/M tee and 05bp06 3/8 blanking cap I fitted these between the metering unit and fuel pipe so the pressure can be tested in future via the blanking cap. Their number is 01603 403190.

The cost was £13.94.

 

Hope this is of some help. Regards John.

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  • 2 weeks later...

An electronic gauge with a sealed sender unit would be ideal. I was warned not to put a mechanical gauge in line on a permanent basis. Any problem in the housing could blow the scale and the glass with nasty consequences :( .

I know it's done on competition cars, but not every thing fine for racing cars is also good for road cars ;)

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http://www.ebay.co.uk/itm/Racetech-Oil-Pressure-Fluid-Temp-Combi-Gauge-With-Back-Light-9ft-Capilary-/290648995570?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item43ac07b6f2#ht_1056wt_1164

 

Why not use this as combined water temperature/ fuel pressure? - with a suitable braided Aeroquip fuel line - no different really from having a mechanical oil pressure gauge that can see 100psi when cold.

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  • 5 weeks later...

Thanks guys, we're getting there but everything looks a bit too "Max Power" and therefore out of place in the wooden dash of a TR in my opinion - the kit on eBay comes close and I the sender issue is annoying but could be overcome. There's got to be a classic looking >120psi reading electronic gauge out there somewhere, surely?

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  • 8 years later...

Bringing this one back up as I'm planning to fit a tee piece so I can hook up a mates fuel pressure gauge which is a female fitting. 

Can anyone confirm this should do the job? 

Male_Female_Male_Tees_720x.jpg.5a1ec34b6b916748a2ee03d1e4ddb773.jpg

It's a male, male, female 3/8 bsp fitting, I would fit a blanking female cap when the gauge isn't connected. 

Thanks

Gareth

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I'd check the actual pipe diameter and threads on your PI system- after 52 years many of the components on my car have been changed and your's could be the same. The threads on the T connection on that fitting look to be LH - like those used in Australia for bottled gas.

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51 minutes ago, Mike C said:

I'd check the actual pipe diameter and threads on your PI system- after 52 years many of the components on my car have been changed and your's could be the same. The threads on the T connection on that fitting look to be LH - like those used in Australia for bottled gas.

This would connect direct to the MU and the fuel pipe will screw on to the bottom thread so that should be alright. 

Something like this:

IMG-20210724-WA0000.thumb.jpg.506b86b4801f8a1398240583154980ca.jpg

As for the LH threads, I'll give them a ring to confirm this isn't just a reversed picture or something. 

Gareth

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If you want the gauge to set up the fuel pressure , I set mine at the PRV end of the MU feed line, in my case that's in the boot. There's more space to set up the gauge and temporary connections. I set the PI  pressure with the engine off.

I don't believe there's much pressure drop in the MU feed line between the PRV and the unit- even at full load.

If you want to leave the gauge permanently fitted to the MU with the engine running or while driving , I'd be worried about vibration unless I fitted an automotive quality pressure transducer to the T piece and connected to an electronic pressure readout.

Edited by Mike C
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Thanks Mike, I'll have a look in the boot to see as another option. A fuel tap might be handy too.

Gareth

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8 minutes ago, Mk2 Chopper said:

Thanks Mike, I'll have a look in the boot to see as another option. A fuel tap might be handy too.

Gareth

I have one fitted to the fuel supply line-it's a 1/2 inch all stainless steel /teflon seated ball valve fitted with suitable reducers. I installed it to make the car safer in the event of a fuel leak that cannot be stopped on the road-it's also useful for changing fuel filters. My other fuel piping, other than the main pump supply pipe, is generally higher than the tank fuel level and less of a risk.

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Budenburg gauge company made a 'T' piece for myself some years ago .

 

                                                                       Harvey

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I got the one I showed earlier and turns out it was the same part no. as an earlier post indicated from a company in Norwich. 

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On 7/25/2021 at 3:06 AM, Mike C said:

If you want the gauge to set up the fuel pressure , I set mine at the PRV end of the MU feed line, in my case that's in the boot. There's more space to set up the gauge and temporary connections. I set the PI  pressure with the engine off.

I don't believe there's much pressure drop in the MU feed line between the PRV and the unit- even at full load.

If you want to leave the gauge permanently fitted to the MU with the engine running or while driving , I'd be worried about vibration unless I fitted an automotive quality pressure transducer to the T piece and connected to an electronic pressure readout.

Seems very sensible to me.  Much more space to swing spanners.

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