Pinto Efi Drops Power When Cornering

[Guest weazel134]

hi chaps

 

recently bought a Sub-k with a pinto EFI. if i run it on a full tank of fuel it runs fine for a few miles, as i get below half a tank and take a roundabout the power drops off until i straighten up again. feels very much like fuel starvation. engine never completely cuts out but when you put foot hard down out of roundabout.... nothing for a second..... then full power again.

 

i was thinking along the lines of fuel moving about in the tank and not reaching the pickup as the level drops?

 

any ideas? fixes etc?

 

thanks guys.

 

Dan

[Guest chris brown]

It either has a swerl pot that is too small or it hasn't got one at all. A common problem, the way most people go is to fit an external swerl pot which feeds the high pressure pump and feed it with a low pressure pump from the tank also feed the return into the swerl pot also. Overflow from swerl pot back into tank.

[Guest weazel134]

Great. Thanks Chris

[tractor]

i fitted one of these then no need for extra pump or external swirl pot

Edited June 20, 2017 by tractor

[Guest lotusPaul]

Have you got a pressure regulator on fuel rail?

I agree lack of fuel but surgeing on a corner may suggest some thing else. Does it do it under hard throttle openings?

[Guest weazel134]

no pressure reg on the fuel rail, if i turn right at a roundabout (fast) is when it's at its worst.

[Snapperpaul]

That is definitely a fuel surge problem.

The basic fuel tank used in the monocoque cars has the fuel gauge & pickup on the far end of the tank, less than half a tank and a brisk attack of a roundabout would cause a loss of power on exit.

I have a fuel pressure regulator fitted, it took a few seconds to drain the carbs and the fuel regulator filter bowl meaning the engine cutting out was 50 meters past the roundabout.

Simply fitting a swirlepot of 1 litre has solved the problem completely.

[Guest weazel134]

well it seems the swirl pot is the answer. thanks for advise guys.

[bullfist]

Many years ago I had exactly the same thing on a Renault Scenic - turning roundabouts, pulling out to overtake on motorway - I momentarily lost power.

This was eventually diagnosed to muck in the fuel tank. Tank cleaned out, new fuel filter, new fuel pump (at my request) - all good again.

-steve

[theduck]

Can you post a picture of the connections on your fuel rail? Id be amazed if there isnt the standard pressure reg there! Agree with others you need a swirlpot, the one tractor posted is from a V8 Land Rover and is what i run as well. Needs a bit of modification to tank and the unit itself to fit but it works very well.

[Guest lotusPaul]

I find this a little confusing. Or maybe im looking at it in a different light.

My lotus runs efi but has no swirl pot.

I have a tank that gravity feeds to a bosche 044 pump (filter before and after)

Jic -6 (or -8, cant remember) fuel lines and connectors,

Going to the fuel rail with fse power boost valve ie fancy long winded name for fuel pressure regulator.

Fuel return goes ditectly to fuel tank.

 

Incidental the emerald controls the pump via a relay and can switch off when throttle is closed.

 

So yes it sounds like fuel starvation but lets look into it properly as i cant remember the fords running swirl pots.

 

You may not have enougth fuel pressure so may need a better pump and or a fuel pressure regulator.

 

Yes you can run a mechanical pump from fuel tank to a swirl pot with a hp electric pump and then go to the fuel rail, pressure regulator should then return to swirl pot.

 

But all you have done here is added more components and therfore more sources of leeks.

 

I would check and confirm fuel pressure at rail before anything.

 

Regards

[Guest weazel134]

ok, so please excuse my basic and pathetic knowlege on this fuel system. the way i understand it is: fuel in the tank goes to the low pressure pump, which feeds high pressure pump. not sure where this is as all i can see is a fuel line into the rail, and i pipe which comes out of the other end of rail (looks like a vacuum hose?????.

 

where is the HP pump?

 

i will post some pics shortly.

[Guest weazel134]

Can you post a picture of the connections on your fuel rail? Id be amazed if there isnt the standard pressure reg there! Agree with others you need a swirlpot, the one tractor posted is from a V8 Land Rover and is what i run as well. Needs a bit of modification to tank and the unit itself to fit but it works very well.

my mistake, looked at a parts breakdown and yes it does have a pressure regulator.

[theduck]

A swirl pot can be in tank or external. The job of the swirl pot is simple, make sure the high pressure pump always has a fuel supply. Early efi cars tended to have a high pressure pump in tank without a swirl pot, but instead had a baffled tank which to some degree achieved the same result. The ideal for combination neatness of installation and functionality is a baffled tank with an intank swirl pot.

[Guest mcramsay]

An lp pump should not directly feed into the inlet of the hp. Either you need to have an HP pump mounted inside the tank with an integral swirl pot ( as per the image tractor posted above) or in a baffled tank. If not then you need an lp pump feeding into a swirl pot which then feeds the hp pump, this allows for a reserve supply of fuel to the hp pump if the lp looses prime due to fuel moving around in the tank when cornering.

 

The pressure regulator will have a vaccum line fitted to it.

 

The outlet of the regulator should return to the swirl pot, the swirl pot should then return to the tank, this ensures any air returns back to the tank.

 

Loosing power on a corner most definitely sounds like a fuel supply issue. Post up some pictures of your set up