Fuel Surge Issues.....

[RonnieG 0]

Funny how the problems just seem to move around as you further develop your car !!

 

My 1990 Mi16'd 205 which I use for track use only never had any problems with fuel surge at any events over the last couple of years and then over the winter I fitted Yoko A048's & a Tran-X LSD to it and now hey presto handling and performance through & out of the bends transformed but at anything below half tank fuel surge/starvation coming in as I exit Knockhill's tight right hand hairpin every lap.....

 

Done a search so here's the options & thoughts as I see them ;

 

1) Keep the tank full - Considering power/weight and all the stripping out I've done this just seems crazy carting about all this unecessary weight for nothing.

 

2) Install a Swirl Pot - I'm not a great fan of the look of these & by the time the Pot, 2nd Pump, Plumbing etc is bought I would probably be lucky to see much, if any, change out of £100 which after buying 2 Tran-X's I don't really have just now.

 

3) PeterT's Cut the Tank in half - I'm probably the most sold on this 'Less is Best'. For me this solution is all about removing rather than adding stuff, 20/30 Ltr capacity is fine for track use & really helps keeps weight to a minimum.

 

What I'm wondering is - Assuming I cut the tank then presumably I can cut a piece out of the waste section to get welded in to the hole created by the cut & if so how easy is it to source somewhere to Plastic weld that section of petrol tank ??

 

I'm sure a certain banned person went down this route but have many others ??

 

P.S. I have already taken the Fuel Pump out to check all the filters/strainers were clean and the base plastic bowl was where it should be.

Edited May 15, 2008 by RonnieG

[Henry 1.9GTi 36]

also after some solutions, get surge below half tank

 

ronnie, was it relatively straight forward to take the pump out and check things are as they should be? This is my next port of call before buying things!

[RonnieG 0]

Henry - As my car is already stripped out then access to the pump is pretty easy. It is located under the offside rear seat - There are 2 black plastic covers on the shell here and the largest one gives access to the pump. The pump has the electric block connector on it which unplugs really easily and then the supply & return fuel hoses, I marked one of these for reconnecting as they both look the same...I also bought a couple of quality small jubilee clips before doing this job as the original Peugeot hose clips aren't easy to re-use. Once the pipes & electrics are disconnected theres about 7 small bolts which seal the pump onto the tank - You just undo them & that lets you remove the pump.

 

 

Do I take it from the lack of comments made so far that anyone that has had any issues with Fuel Surge has just gone down the Swirl Pot route ??

Edited May 16, 2008 by RonnieG

[Baz 421]

Is this not just a case of having a different pump? As there's 2 different pumps from early and later cars, if the one you have starves then it's the wrong (shorter i guess) one. My old Mi16 used to do it when i changed the pump to an older one, but put the right one back in and hey presto, all good again.

 

It may be the case even on the 'right' pump with slicks and a diff though of course.

Edited May 16, 2008 by Baz

[C_W 3 1 Cars]

Mine's an 88F and surges on anything less than 2/3rds full so I always run with an almost full tank and constantly top it up. It does vary track to track though so sometimes it might get closer to half a tank before surging. There was a suggestion that the later tanks are better baffled but then the mention of a different pump is someting that may be linked to the difference.

[TT205 42]

On standard injection/plenum I had fuel starvation especially on right handers on anything less than half a tank with my TurboTechnics 205

 

On my n/a 1.9 on carbs with a short pickup I could run on fumes with no other mods! - maybe the float bowls are big enough to prevent this?

 

When I swapped to throttlebodies all of a sudden (same car/engine with same pick up) I had starvation again - I went the swirl pot route and genuinely can run on fumes again

[jonnie205 1]

fit a swirl pot or smaller tank, running round a track with full tank of fuel is insane especially when most people try and save weight on track cars

[C_W 3 1 Cars]

fit a swirl pot or smaller tank, running round a track with full tank of fuel is insane especially when most people try and save weight on track cars

 

I've heard/seen these but what exactly does a swirl pot do? is it a float chamber like a kind of reserve for the fuel?

[Doof 11]

Its just effectively a tiny fuel tank that is always kept full by your main tank...apart from when the main tank can't draw any, in which case there is enough in the swirl pot to last a good few minutes and with it being particularly narrow the fuel can't slosh around like the primary tank.

[petert 554]

Your plastic welder needs to be sh*t hot if you're considering cutting the tank. I've sent several back for warranty claims. In the end, it's probably better to buy a small fuel cell that has all the goodies built in.

[James_R 3]

I'm planning to have a swirl pot fitted to mine when it's back again I would also suffer surge on anything less than 1/2-1/3 of fuel on the track, but oddly not till about 5 secs after the corner.

 

Swirl ports are abotu 1L althoguh you can get different sized ones, you have a low pressure pump which feeds the pot off the main tank, and an overflow going back to the tank, so it's kep almost constantly full, then the high pressure injection pump feeding off the swirl pot. you should also have a return from the fuel rail to the swirl pot, but I tend to think the fuel will start getting pretty warm if you circulate it through the fuel rail and back.

 

I've decided to run mine under the boot floor (along with the battery) and flat bottom the underside from the beam tube to the valance to stop debris hitting it, I'm just not kean on it sharing the space inside the car with me although lots of people do :s

 

That said, golf GTi fuel pumps are meant to have a built in swirl pot of about 1/2 a L if that enough for somepeople.

[Henry 1.9GTi 36]

I would also suffer surge on anything less than 1/2-1/3 of fuel on the track, but oddly not till about 5 secs after the corner.

 

same James, after finishing a corner and getting almost straight, car would die and then suddenly come back to life.

 

Will a golf GTi fuel pump fit into the standard location? and what mk of golf?

 

Henry.

[Spiky 37]

i used to get surge on track

 

i get nothing now

 

 

 

[RonnieG 0]

Lot of interesting comments !

 

My symptoms are the exact same - After finishing a corner and getting almost straight, car would die and then suddenly come back to life.

 

Henry - On the Golf Gti pump front I managed to have a look at Mk 2,3 & 4 Golf tanks at the weekend and they all had larger diameter fuel pumps with a large screwing cap arrangement to seal the pump to the tank which is a completely different size and setup to the Peugeot bolt on one - I can only assume anyone going down this route is maybe fitting the complete Golf fuel tank & pump at the same time…..

 

As it would not appear anyone on this forum has gone down the 'chopping the tank route' and I'm still not finding it easy to get anyone to plastic weld my current petrol tank this option ain't looking so good now !

 

Looks like I'm just going to have to fork out at some point, sooner rather than later I suspect, in going down what seems the most commonly used route of buying a Swirl Pot, 2nd pump, plumbing etc etc.

 

Thanks for posting the photos Steve - Really useful & pictures worth a thousand words etc…

 

Do you use the engine fuel return pipe as the intake to supply your secondary pump?

[Spiky 37]

hi

 

my setup

 

uses the std pump in tank to feed the switl port

 

then have a return from the siwrl pot back to tank

 

then from the bottom of the swirl port, feed into the second pump, which then pumps to the fuel rail

 

then the return from the fuel rail feeds the swirl port

 

eliminatinng all surge so far

[petert 554]

Are you allowed to have fuel pipes in the cabin?

[Spiky 37]

for rallying and everyother racing,

 

having them underneath is dangerous

 

all the rally cars i've seen are inside.

 

as long as they are secure it's fine

[petert 554]

We're allowed to have them inside, but they have to be encased, so in the event of the fuel leak, there is no chance of spraying over the driver.

[Spiky 37]

ahh i see

 

probably a very good idea

[taylorspug 7]

Just dont put the pot there, putting a large amount of flammable liquid in the cabin pretty much underneath the drivers seat isnt top of the pops ideas-wise.

[Spiky 37]

it's there and staying there now

 

those fittings are expensive.

 

i'm planning on putting a purspex type sheild over it in the future, to stop anthing hit it (when travelling to track days) and for a safety aspect

[RonnieG 0]

Did a bit more research today & came across an ex-member of this forum who has been using PeterT's 'chopped tank solution' to great effect over the past couple of years. He has been running on track well beyond the dash fuel light being on without any hint of fuel surge.

 

Definately increased my interest again with the simplicity, allround weight reduction and hopefully cheapness of just reducing the size of the tank!

 

We deal with a plastics company through work so I called them today and we're going to cover this more next week so here's hoping.....

Edited May 21, 2008 by RonnieG

[ifcho 0]

I am thinking of chopping my fuel tank as well, as this sounds as the simpliest and most effective solution. I don't like swirl pots, as they add many fuel connections and having a few liters of fuel in the hot engine bay doesn't look great to me :-)

 

I found the pic petert has posted (after doing many searches, so I'll repost it here):

petert's fuel tank:

 

Here is the situation - I have three fuel tanks and two cars - one of the new type and two of the old type (one is fitted to my carbio).

The new one is definitely improved as it has a fuel bowl for the pump, and supposable some baffles inside.

On my cabrio I have the old type fuel tank and I fuel surges quite often...

 

And now I am wondering .... should I cut the new tank and fit it to my car, or cut the old style tank and fit the new one to the cabrio?

[ifcho 0]

not a lot of opinions on this issue huh

[blackscooby 0]

I run a cut and shut tank on our track day motor. Run full slicks and only rarely have surge. Looks identical to Pete's tank above. Works very well, especially considering least is best (cost that is !)

 

At the end of last season we had a small leak, but not from a join but from the exhaust melting the tank. It was a sod to try and resolve, but eventually we did. It took us hours to plastic weld it. On slicks the exhaust moves too much so we've had to create a wire strap mechanism to stop its lateral movement. In addition the exhaust is totally encased in heat wrap, plus the tank is lagged to prevent it happening again.