conversion problems flippin Fuel pump

pampoen · Post by **pampoen** » Mon Jun 07, 2010 12:32 pm

When i did my 7mge conversion i placed the fuel pump directly under the fuel tank and it is connected to a surge tank fuel cell which is fed from a hole in the bottom of the tank and connected to my VW 2.5 fuel pump which when on level ground does splendidly well,but im guessing because of the compartments to stop fuel swishing around in the tank and because the pump is connected to one side of the tank every time my tank is half full and i go up a hill the pump sucks air and i lose power which is not cool for offroad!!! has anyone fitted a submerged pump before? what pump have you used? has anyone changed there tank? How hard is it to fab one and how much would they retail for? so many questions!!! so little time!!!

Post by **JohanM** » Mon Jun 07, 2010 12:50 pm

Luke

the reason why your set up is not working is because the gravity feed from the tank to the surgetank is not "controlled".

As far as I can understand you do not use the steel pipe coming out of the tank. That pipe is designed to pick up the fuel from the bottom of the tank and also has a seive attached to the end in the tank to prevent dirt from going into the fuel line.

Also when doing a surge tank it it best to mount the surge tank infront of he main tank to either gravity feed it into the surge tank or use a Low pressure pump like a Flasher pump to keep the surge tank full.

Then the HP pump can be used from the surge tank to the fuel rail.

Also the return line should be conncted to the surge tank and the surge tank to the main tank to prevent the system from over pressurizing it and blowing a pipe off.

Hope this help you.

Gunta · Post by **Gunta** » Mon Jun 07, 2010 1:14 pm

Luke, I have the same problem. I still need to work out the best way to do this.
If anybody has done this, some pics would be nice.

Mr_B · Post by **Mr_B** » Mon Jun 07, 2010 1:42 pm

I used the original fuel pickup in the tank, just upgraded the 8mm steel pipe to 12mm, copied the profile of the original pickup pipe, just made sure it's 100% at the bottom... there are no baffles in the std Hilux tank... I've looked... I don't have any surge, or LP feeder pump... my setup:

[Petrol Tank]->12mm ID pickup->[LP fuel filter]->12mm ID fuel hose->[HP fuel pump]->8mm ID fuel hose->[HP fuel filter]->8mm ID fuel hose->[Fuel Rail]

I keep the tank above 1/4 full when offroad... never had a problem with fuel starvation... even on long dune charges...

Mr B

Post by **CasKru** » Mon Jun 07, 2010 1:58 pm

On my setup I've got an 8mm pipe running from the normal pickup to a filter through a facet pump into a 1.5L surge tank. From the surge tank through another filter through the high pressure pump to the fuel rail. From the FPR the return goes to my surge tank and not the main tank.

Till not absolutely not problems and I have run to very close on empty.

Gunta · Post by **Gunta** » Mon Jun 07, 2010 2:07 pm

Cassie, have you got any pics of your setup?

Post by **CasKru** » Mon Jun 07, 2010 2:24 pm

I had a look but don't seem to have any. I can try to take some this weekend.

Gunta · Post by **Gunta** » Mon Jun 07, 2010 2:32 pm

That will be great, Thanks

Mr_B · Post by **Mr_B** » Mon Jun 07, 2010 2:42 pm

I've got this diagram of what Cassie describes... I was going to go this route as well, but haven't needed to

: fuelSupply.gif (19.4 KiB) Viewed 4215 times

The FPR return and fuel tank inlet connect to the top of the surge tank, with the outlet to the HP pump at the bottom...

MrTurbo will probably have a surge tank or 2 for sale...

Mr B

Post by **CasKru** » Mon Jun 07, 2010 4:02 pm

That is exactly the setup... :)

Spartan · Post by **Spartan** » Mon Jun 07, 2010 4:16 pm

My 6 loop lekker en ek het nie al die probleme nie, het dit ook nog nie gehad nie. Op n 6 kan jy nie rond tjorrel met n LP pomp nie. Maak jou suction pyp dikker soos Mr B se en gebruik die selfde soort HP pomp vir suction as wat jy gebruik om jou petrol na die fuel-rail toe te pomp. En Johann is reg met wat hy se dat die return line na die anti-surge tank toe moet gaan, n pyp van daaraf terug (van die anti surge tank af) na die groot tank toe om druk te voorkom. Oja en 500ml vir die 6 is baie temin kyk na so 2-3L tank. Sorg dat jou inlet van die groot tank af bo ingaan en die suction kant wat fuel-rail toe gaan onder is. Die return na die groot tank moet jy ook maar aan die bokant sit.
Hoop jy kom reg, hier is n ander topic wat die goed bespreek en wat fotos het.

Maddoglips · Post by **Maddoglips** » Mon Jun 07, 2010 4:23 pm

Very interesting , I must say.

Now would it be acceptable to have a mechanical pump feeding the surge pot and then the rest if it was to be used on a 2.2 EFI conversion as I don't believe she should need such a high pressure and the mechanical I imagine should be able to keep up with the demand?

Cheers

Zane

pampoen · Post by **pampoen** » Mon Jun 07, 2010 5:02 pm

what low pressure pump would you recommend? as i dont have a low pressure mechanical pump like the old 2.2

Post by **CasKru** » Mon Jun 07, 2010 8:41 pm

Here is pics of my setup I found on my PC. It does not show specific details but you will get the idea. If you still want I will take pictures this weekend.

1) Fuel filter
2) Facet fuel pump
3) Surge Tank
4) High Pressure Pump
5) High Pressure Fuel Filter

pampoen · Post by **pampoen** » Mon Jun 07, 2010 9:44 pm

Cool guys thanks for info but whats this Facet fuel pump? i see my setups completly wrong,my tank cover plate hangs about 50mm lower than before as a result :{ never let a drag racer from a certain area near durban do your fuel system conversion!!

Post by **CasKru** » Mon Jun 07, 2010 10:12 pm

pampoen wrote:Cool guys thanks for info but whats this Facet fuel pump? i see my setups completly wrong,my tank cover plate hangs about 50mm lower than before as a result :{ never let a drag racer from a certain area near durban do your fuel system conversion!!

Facet pump AKA low pressure fuel pump. Works with a diaphragm

AFAIK they are not so sensitive to airlocks etc.

Demon · Post by **Demon** » Mon Jun 07, 2010 10:15 pm

I would look at the main pump before I look at a surge tank setup. What is your flow rate and pressure on your current pump ? Im looking to go for the bosch 044 and it's strong. 300 LPH and can go to 6 bars. I suspect that this hilux pump is running out of steam at top end and thus causing poor atomization and maybe affecting the fuel consumption.

Gunta · Post by **Gunta** » Tue Jun 08, 2010 7:31 am

I am already running the Bosch pump. It might be a bit overkill but The pressure and volume is there. What ever fuel is not needed goes back to the tank. I am running a 19mm pipe from the tank to the fuel pump, so I have not had any problems with airlocks. My only problem is when the tank is on empty and I go around a corner that the engine starves for a few secs. Once I am around the corner it recovers quickly. I reckon all I need is a small surge tank just before the pump and it will sort out that problem.

Where do I get one or have one made up?

Maddoglips · Post by **Maddoglips** » Tue Jun 08, 2010 7:37 am

Mark

I'm busy making 1 at work for my EFI conversion, go to your nearest engine machine shop, and ask for a old cylinder lining.

I got 1 for free from them as they are scrap and should hold depending on the 1 you choose, about 1/2 a litre which should be ample.

Just weld the ends closed with plate and add the pipes/inlets you require.

Oh and it looks neat cause you can polish it if you want.

Zane

Post by **CasKru** » Tue Jun 08, 2010 7:44 am

I was so lucky to get mine from a fellow member and it's made of aluminium

Gunta · Post by **Gunta** » Tue Jun 08, 2010 7:47 am

Zane, do you mean a sleeve? and which one did you use.

Gunta · Post by **Gunta** » Tue Jun 08, 2010 7:57 am

I wonder if one can use a VW Combi filter before the pump to act as a surge tank.

Maddoglips · Post by **Maddoglips** » Tue Jun 08, 2010 7:59 am

Hi Mark

You're spot on, I'll try and get a pic.

I'll try and take some piccies now this morning as it's here at work and post them.

I think it's an Isuzu 1, if you not in a hurry, I will try and get you 1 and send it.

Zane

Gunta · Post by **Gunta** » Tue Jun 08, 2010 8:13 am

Thanks Zane that will be great. When you make it, are you making the inlet at the top and the outlet at the bottom? How do you propose to mount it to the body? Maybe one can weld a plate on the side so we can bolt it onto the chasis. You might have to braise it because the sleeves are cast iron.

Maddoglips · Post by **Maddoglips** » Tue Jun 08, 2010 8:39 am

Hi Mark

I'm planning on having the outlet at the bottom, return to tank at top, return from fuel rail half way and the inlet from mechanical pump (LP) half way.

The sleeve I have, is mild steel, well lets say it aint cast iron, my welder checked this first.

As for the mounting, was planning on just a flat bar across with holes to secure it to the firewall/wheel arch.

Zane

Gunta · Post by **Gunta** » Tue Jun 08, 2010 8:45 am

Why do you want to use a LP pump? I am sure that once the surge tank is full being gravity fed and being mounted lower than the tank you would not need a LP pump. You only need enough petrol to keep you going while the petrol in the tank has moved to the otherside when going around a corner.

Maddoglips · Post by **Maddoglips** » Tue Jun 08, 2010 8:51 am

Hi M8

I'm planning on mounting my surge tank/swirl pot in the engine bay, along with the HP pump.

This allows me to keep things realitivly close to standard on the piping side and should I ever get into a situation where I need to go back to carb, I can with no hassles.

I'm also planning on using the standard pick up from the tank so gravity feed would'nt work that well.

Zane

pampoen · Post by **pampoen** » Tue Jun 08, 2010 8:52 am

Wouldn't this affect your belly clearance though having the surge tank gravity fed from the main tank?surely it would be better to have it fed with a little pump somewhere higher up on the chassis?

Gunta · Post by **Gunta** » Tue Jun 08, 2010 9:11 am

My pump is a foot away from the tank and mounted on the inside of the chasis ladder. It has been there for 6 years with no problems, so I plan to mount the surge tank in between my tank and the pump. I reckon there is enough space to mount it slightly lower than the tank to gravity feed and still be out of harms way. I dont have much space in the engine bay and it will be easier to get to under the vehicle to do repairs if any.

Spartan · Post by **Spartan** » Tue Jun 08, 2010 4:04 pm

Maddoglips wrote:Very interesting , I must say.

Now would it be acceptable to have a mechanical pump feeding the surge pot and then the rest if it was to be used on a 2.2 EFI conversion as I don't believe she should need such a high pressure and the mechanical I imagine should be able to keep up with the demand?

Zane
Injectors need pressure otherwise you would not get the right effect, all car using a efi system have a HP pump

Maddoglips · Post by **Maddoglips** » Tue Jun 08, 2010 4:15 pm

Spartan wrote:
Maddoglips wrote:Very interesting , I must say.

Now would it be acceptable to have a mechanical pump feeding the surge pot and then the rest if it was to be used on a 2.2 EFI conversion as I don't believe she should need such a high pressure and the mechanical I imagine should be able to keep up with the demand?
Zane
Injectors need pressure otherwise you would not get the right effect, all car using a efi system have a HP pump

Jaco, apologies for not making it clear, but I plan on putting a HP pump after the swirl pot, just need to know if the mechanical pump is sufficient to feed the swirl pot?

Cheers Zane

Mr_B · Post by **Mr_B** » Tue Jun 08, 2010 5:35 pm

Look at the diagram, LP pump feeds the surge tank, between the surge tank and fuel rail you must have a HP pump, petrol fuel injection needs between 2.5 and 3.5 in the fuel rail for the injectors to work properly.

Maddoglips · Post by **Maddoglips** » Tue Jun 08, 2010 6:05 pm

Mr_B wrote:Look at the diagram, LP pump feeds the surge tank, between the surge tank and fuel rail you must have a HP pump, petrol fuel injection needs between 2.5 and 3.5 in the fuel rail for the injectors to work properly.

Hi Bretton

what I would like to know is,

the mechanical(LP) pump on the engine, is it's flow rate/supply gonna be sufficient - well it be as effective as the electric 1's. To supply the swirl/surge pot.

Some guys say yes others say no so still getting some more input to help decide.

Cheers Zane

Demon · Post by **Demon** » Tue Jun 08, 2010 6:44 pm

It should work because you have got your return back from the motor which is feeding that surge tank aswell.

Whats causing your pick up to suck air ? Iv never had any crap with my hilux and even now with the 1J motor. Maybe the fact that you have put a exterior pump and your pick up is alot smaller. I see that the bosch in tank pump has got a huge pick up area

Demon · Post by **Demon** » Tue Jun 08, 2010 9:23 pm

Do any of you guys know what the 2.7 fuel pump flow rate is ? Can't seem to find any info on that pump

Spartan · Post by **Spartan** » Thu Jun 10, 2010 3:42 pm

Luke
This is what my setup looked like when I did the conversion, I am going to change the pipes to braided hoses when I get a chance

Gunta · Post by **Gunta** » Fri Jun 11, 2010 7:40 am

Thats a very nice looking job there. Who made it and how much?

Spartan · Post by **Spartan** » Fri Jun 11, 2010 7:56 am

Gunta wrote:Thats a very nice looking job there. Who made it and how much?

Gunta
That was a bit of a expensive exercise, about 7.5K, and my brother made it for me since I am out of country, and he did not smoke me, I got all the slips.

Gunta · Post by **Gunta** » Fri Jun 11, 2010 8:13 am

Ouch my balls hurt and I have a cough

I have already spent about R85k on my hilux plus the cost of the vehicle which means I can never sell it.
My aircon cost close to R9k on my 7mge to custom make under the vehicle.
I think I will have to make another plan, but yours really does look good.

Mr_B · Post by **Mr_B** » Fri Jun 11, 2010 9:15 am

Maddoglips wrote:
Mr_B wrote:Look at the diagram, LP pump feeds the surge tank, between the surge tank and fuel rail you must have a HP pump, petrol fuel injection needs between 2.5 and 3.5 in the fuel rail for the injectors to work properly.
Hi Bretton

what I would like to know is,

the mechanical(LP) pump on the engine, is it's flow rate/supply gonna be sufficient - well it be as effective as the electric 1's. To supply the swirl/surge pot.

Some guys say yes others say no so still getting some more input to help decide.

Cheers Zane

Zane, the flow rate shouldn't be an issue, a LP pumps flow rate is usually good, but it cannot generate the required pressure... here are the facts:

Facet LP fuel pump flow rate: 95 litres/hour or 1.58 litres/minute
Avr. HP fuel pump flow rate: 300 litres/hour or 5 litres/minute

Let's say the that only half the HP pump fuel supply is returned via the FPR, then the swirl pot would have a feed rate of around 4 litres a minute... I'm pretty sure 4 litres a minute would suffice... else you could always run a second LP pump... but then things may get noisy...

Mr B

Maddoglips · Post by **Maddoglips** » Mon Jun 14, 2010 2:34 pm

Maddoglips wrote:Hi Mark

You're spot on, I'll try and get a pic.

I'll try and take some piccies now this morning as it's here at work and post them.

I think it's an Isuzu 1, if you not in a hurry, I will try and get you 1 and send it.

Zane

Apologies for the delay, but better late then never

Gunta · Post by **Gunta** » Tue Jun 15, 2010 10:09 am

Thanks Zane, I think that should work quite well.