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Cal-look/High Performance => Technical stuff => Topic started by: LoopyLoo60 on December 10, 2019, 21:43:46 pm



Title: Fuel pressure regulator fitting/sanity check
Post by: LoopyLoo60 on December 10, 2019, 21:43:46 pm
Hi all,

I've had a couple of teething problems with the engine and the person who built my engine has added a fuel pressure regulator. This seems to have fixed my running issues but I'm a little nervous about the part he has used and the position he has decided to place it. I'm no mechanic though so happy to be told it's fine!

Pictures in posts below.

As you can see, it's not mounted to anything. Would you be happy driving round with this or should I get it moved somewhere else?

Thanks  :)


Title: Re: Fuel pressure regulator fitting/sanity check
Post by: PPRMicke on December 11, 2019, 10:01:29 am
Hi all,

I've had a couple of teething problems with the engine and the person who built my engine has added a fuel pressure regulator. This seems to have fixed my running issues but I'm a little nervous about the part he has used and the position he has decided to place it. I'm no mechanic though so happy to be told it's fine!

Picture below.

(https://cdn1.imggmi.com/uploads/2019/12/10/80adc1e2a356c5ca83e23bbb1abf6ecd-full.jpg)

As you can see, it's not mounted to anything. Would you be happy driving round with this or should I get it moved somewhere else?

Thanks  :)

Picture ??
/// M


Title: Re: Fuel pressure regulator fitting/sanity check
Post by: LoopyLoo60 on December 11, 2019, 13:00:10 pm
Sorry, I'm not very good at posting photos. Hopefully you can see the image below.

[attachment=1]


Title: Re: Fuel pressure regulator fitting/sanity check
Post by: LoopyLoo60 on December 11, 2019, 16:04:37 pm
From another angle.

[attachment=1]


Title: Re: Fuel pressure regulator fitting/sanity check
Post by: PPRMicke on December 11, 2019, 16:43:27 pm
Have seen worse solutions than you have
You can try to remove the electric cable from the hose
   You can build it off but it requires mechanics
  The most common error is that the fuel pump is not shimmied up for the correct fuel pressure depending on which carburetor you use.
/// Micke


Title: Re: Fuel pressure regulator fitting/sanity check
Post by: spoolin70 on December 11, 2019, 16:45:19 pm
Are there any threaded holes or mounts or anyway of attaching a bracket to the regulator ?

Any manafacturer name on it ?



Title: Re: Fuel pressure regulator fitting/sanity check
Post by: WhiteTrash on December 11, 2019, 18:56:55 pm
That is a typical Chinese Cheapo McCrappy universal pressure regulator. https://www.ebay.co.uk/itm/Universal-Adjustable-Gunmetal-Fuel-Pressure-Regulator-For-Carburetor-Engine/123686056023?hash=item1ccc437057:g:BdwAAOSwNAtchgXB
They have no way of mechanically fixing them to anything unless you start making brackets. Than you may as well get a good quality regulator.
To adjust the pressure on these things, you push the top disc with the arrow down and then turn them to whichever position number you need.
However, you obviously have twin carbs fitted and I've never known a standard mechanical fuel pump deliver too much pressure for something like that. These pumps are designed to fill a single, stock carburettor with no regulator at all and only rely on the needle valve to shut fuel supply off.
If your engine wasn't running right, was it because it was over fueling because the floats in your carbs are not adjusted correctly. If they are shutting off too late, the fuel bowls overflow and it drips into the engine making it run too rich and lumpy.
By fitting a regulator, your mechanic may have just slowed the filling of the fuel bowls down so much that it not overflows. So what happens when you go flat out now? Have you tried it? Does it start to misfire after a while? If so you may be running too lean because your not getting enough fuel because it's been regulated down too much.
Your first step is to check the floats are adjusted properly and than go from there.
Frank


Title: Re: Fuel pressure regulator fitting/sanity check
Post by: LoopyLoo60 on December 11, 2019, 20:41:08 pm
Thanks for the replies everyone.

I can confirm there is no obvious manufacturer name so it appears to be a cheap Chinese job. I did suspect this when I saw the dial which is what prompted me to first post.

In relation to going flat out. I have not yet had the chance. I was running the engine in first but bad weather and work has stopped me getting out in it much. It's not a great time of year here for driving.

The whole running lean is interesting though. The reason the regulator was fitted was because there was a smell of petrol and dripping from the carbs after running the engine. I wonder if the fix was as simple as tweaking the float valve instead of masking the problem?

I have to say that I have lost confidence in the person who built the engine. I will go back to him to see what he says but think the sensible option is to take it elsewhere for a good service and tune up. That might fix the original problem and get rid of the need for the fuel pressure regulator. It will also give me a little more confidence in the car.


Title: Re: Fuel pressure regulator fitting/sanity check
Post by: Martin S. on December 12, 2019, 00:00:31 am
You have a fuel pump without a built-in shut-off valve as well. Originally VW had one in the top of the fuel pump. These were the earlier taller pumps. When alternators came out VW moved the shut-off valve into the fuel lines as a plastic device which are now long gone considered unnecessary by mechanics and I’ve only ever seen one in the Bentley. 
My cars all now have a new replacement pump which has the valve but cost double what yours cost.
I also use a fuel pressure gauge to set the pressure below 3psi. Mine needed the longer rod ground down from 4-1/4” to about 4-1/8” which is half way to the short 4” rod. Hard to do all this without a gauge. 

No more post-carb drip and gas smell in the garage.  ;)


Title: Re: Fuel pressure regulator fitting/sanity check
Post by: alex d on December 12, 2019, 09:39:14 am
you might or not might need a regulator, but if you need one you can't go wrong with a Malpassi