2L 8V conversion fuelling

I've got an agg to swap into my 1.5GX that is running on a carb. I'm trying to figure out how the conversion to electric fuel injection works. Planing to swap in a gti fuel tank and put in new 8mm fuel lines, but I'm not sure what fuel pump i'd need and if a swirl pot is essential?

The fuel tank swap is to avoid the need for extra fuel pumps or a reservoir if at all possible, trying to keep things simple. The car isn't going on a track so hoping the swirl pump isn't necessary.

It's my first project and am learning on the job, any advice would be greatly appreciated. Also am clueless about wiring atm but have the full loom and ecu for the AGG.

Cheers, 

Not all fuel tanks are the same, ie: and 84.5 and older uses a 10 gallon tank  swirl pit internal t the tank and no in-tank pump.

A 84.5 and newer uses a 13 gallon tank, no swirl pot internally an in-tank as well as an external pump, and depending on the injection the external pump is 75 psi out and 45 psi in, along with a plethora of additional parts for CIS, including a external filter/swirl pot, that the primary fuel system uses to prevent fuel starvation in Turns when running 1/4 of a tank on fuel.

The easiest way to tell tank size for your frame is if you have a Full Sized Spare tire, or a Space Saver (donut) Tire.  The Full sized spare requires a 10 gallon tank whereas the Space Saver tire requires a 13 gallon tank.

Digifant 1990 or newer uses Digifant, the external swirl, 2 pumps one in-tank and one External. and a lot less fru-fru to the fuel pressure regulator attached to the fuel rail.

See: https://volkswagen.7zap.com/en/usa/rabbit+conv+golf+cabrio/conv/1990-44/2/

for some of the differences.

Ok good info cheers! Sounds like i've got a 13 gallon tank then.

The AGG is going to be electric fuel injection. Any recommendations on a simple set up to fuel it?

 

I thought the  Mk1 1.5 GX is an 1983 tin top not a cabriolet?
If it's a tin top I would guess you have the full size spare wheel and the smaller 40l tank as I believe it's only cabriolets which have the larger fuel tank? I could be wrong….

Maybe best to clarify which car you have and the year.   Is your like this?

https://www.carandclassic.co.uk/car/C759798

sorry I was a bit of a doughnut there… yep its a 83 1.5 GX tintop with a full size spare wheel, exactly like that link!

Planning on keeping the original 4+E gearbox but with a new 210mm clutch, the AGG is in good nick but have new gaskets to put in and some slight cosmetic work to do.

The car is solid and i'm feeling naively optimistic about the swap. I'm just yet to figure out the fuelling and wiring, so any help would be really appreciated!  

Well, we all get a little buzzed over on this side of the pond, and me with my Cabriolet/Diesel knowledge is a bit different from specifics between versions.  as I didn't know the specifics I know when the tanks were switched over…. so on yours a 10 gallon tank.

CKinally said

The car is solid and i'm feeling naively optimistic about the swap. I'm just yet to figure out the fuelling and wiring, so any help would be really appreciated!  

When playing with fuel, open ventilation lots of it, and no open sourced flames battery disconnected.  Best advice I can give to ya.

ps.  The 10 gallon tanks were bottom feeders.

I guess you will need some sort of swirl pot as the smaller tanks do suffer from fuel starvation unless you have an original GTi fuel tank which are no longer available as the new ones advertised are diesel tanks with a very crude swirl pots fitted in the tank.

I don’t know what fuel system was used in a Mk3 golf or how it works so sorry I can't be much help on fueling but I think a few people have done the conversion.

https://vwgolfmk1.org.uk/forum/index.php?page=topicview&id=technical%2Frunning-gear_2%2Fagg-engine-loom

AGG with carbs.
https://vwgolfmk1.org.uk/forum/index.php?page=topicview&id=specialist%2Fmodifications-and_2%2F2-litre-8v-conversion

https://www.clubgti.com/forums/index.php?threads/mk1-2-0l-8v-agg-conversion.272838/

lots of info here..
https://vwgolfmk1.org.uk/forum/index.php?page=topicview&type=misc&id=modifications-and_2%2Ffrom-1-6-to-2-0-8v-what

Loads of threads out there so have a google (other search engines available..)

Briano1234 said

ps.  The 10 gallon tanks were bottom feeders.

Not true, carb cars like the 1.5GX have a level sender/fuel pipes for send and return at the top.

The GTIs had an extra port at the bottom though (but this isn't a GTI).

paul_c said

Briano1234 said

ps.  The 10 gallon tanks were bottom feeders.

Not true, carb cars like the 1.5GX have a level sender/fuel pipes for send and return at the top.

The GTIs had an extra port at the bottom though (but this isn't a GTI).

so is that an extra port on the bottom of the fuel tank on a GTI

correct me if i am wrong so fuel to the distribution
unit wether carb multi or single point injection needs
to be recycled to a another delivery point fuel tank
fuel pump or another storage vessel is that not true

mark1gls said

I guess you will need some sort of swirl pot as the smaller tanks do suffer from fuel starvation unless you have an original GTi fuel tank which are no longer available as the new ones advertised are diesel tanks with a very crude swirl pots fitted in the tank.

Thanks!

So it sounds like to stick with my existing fuel tank I'd need to get a lift pump, which feeds some sort of reservoir under the car (guessing this is the same as a swirl pot),  then a main external pump which gives the pressure needed for EFI.

Was trying to avoid having so many moving parts by swapping to GTI tank and having just one pump (vaguely mentioned on another tread), but sounds like that's the tank which isn't available!

Cool, i'll look into the lift pump etc. route, cheers for the info    

 

so in which direction would you go
if the tank which you have just
purchased brand new does not have
any type of swirl pot is that the question
ckinally is asking ? the fuel supply to the
front of the car is not an issue in my view

nicci21paul said

so in which direction would you go
if the tank which you have just
purchased brand new does not have
any type of swirl pot is that the question
ckinally is asking ? the fuel supply to the
front of the car is not an issue in my view

I have a carb tank without an internal swirl pot.

You need a plastic cabriolet swirl pot.



Get a late cabriolet lift pump where the outlets go forward towards the wiring connector. You can use a polo lift pump but the outlets face away towards the back of the car and make running the fuel lines tricky.

Mount a gti fuel pump or Bosch 044 in the gti cradle. I bought a stainless version from CQ. Mount the swirl pot where the gti accumulator is positioned, again bought a stainless cradle from CQ.

Connect the fuel system like so:



Alternatively source a good gti tank (hard to come by) and gti fuel setup.

Cheers

Rich

There are alot of people using aftermarket tanks with no problems, it's the same design as a caddy tank and they work fine on the sport with no extra swirl pot.

I prefer to have the extra protection with no chance of  fuel starvation. It was good enough for the cabriolet.

I guess it ultimately comes down to driving style.

Rich. said

nicci21paul said

so in which direction would you go
if the tank which you have just
purchased brand new does not have
any type of swirl pot is that the question
ckinally is asking ? the fuel supply to the
front of the car is not an issue in my view

I have a carb tank without an internal swirl pot.

You need a plastic cabriolet swirl pot.



Get a late cabriolet lift pump where the outlets go forward towards the wiring connector. You can use a polo lift pump but the outlets face away towards the back of the car and make running the fuel lines tricky.

Mount a gti fuel pump or Bosch 044 in the gti cradle. I bought a stainless version from CQ. Mount the swirl pot where the gti accumulator is positioned, again bought a stainless cradle from CQ.

Connect the fuel system like so:



Alternatively source a good gti tank (hard to come by) and gti fuel setup.

Cheers

Rich

i am not asking for help or advice for myself just an easy solution for the member who started the post i am aware of the fuel line setup cheers paul

i have two or three external swirl pots lying about
a few pumps and accumulators i do have two new
fuel tanks in cabriolets with out internal chambers
obviously different members have different views
so maybe better to work things out youself to suit
yourself

pick the best for for yourself

nicci21paul said

i am not asking for help or advice for myself just an easy solution for the member who started the post i am aware of the fuel line setup cheers paul

Sorry about that Paul, I was meant to quote the poster.