EFI conversion

Dedicated to owners of Citroen GS and GSA models.

Moderator: RichardW

Raul
Posts: 133
Joined: 05 May 2012, 05:37

EFI conversion

Post by Raul »

Hi

Anyone here who has done it or considering it in the future?

User avatar
CitroJim
A very naughty boy
Posts: 41632
Joined: 30 Apr 2005, 23:33
x 1079

Re: EFI conversion

Post by CitroJim »

Raul wrote:
08 Jan 2018, 19:42
Hi

Anyone here who has done it or considering it in the future?


On what precisely?

Raul
Posts: 133
Joined: 05 May 2012, 05:37

Re: EFI conversion

Post by Raul »

On citroen gs/a . There are some old youtube videos of the cars that have been converted but a link to the step by step build thread would be excellent.

User avatar
CitroJim
A very naughty boy
Posts: 41632
Joined: 30 Apr 2005, 23:33
x 1079

Re: EFI conversion

Post by CitroJim »

Gosh! Converting a GS/A to EFI sounds to me like a big project indeed...

These days I guess Megasquirt would be the way to go...

User avatar
Michel
Posts: 1750
Joined: 29 May 2017, 13:50
x 327

Re: EFI conversion

Post by Michel »

CitroJim wrote:
09 Jan 2018, 10:44
Gosh! Converting a GS/A to EFI sounds to me like a big project indeed...

These days I guess Megasquirt would be the way to go...


Looked into this for the DRK with a megasquirt .Not too bad or expensive to do both fully electronic ignition and fuel injection. The theory for the GS would be the same, though siting the injectors and supply to them would be interesting. Plenty of other flat-fours with injection though.

Could get rid of the awful dizzy too..

Raul
Posts: 133
Joined: 05 May 2012, 05:37

Re: EFI conversion

Post by Raul »

I found a thread about vw beetle:
https://www.aircooledvwsa.co.za/viewtop ... =4&t=27984
Quote from there:
"I'm in the process of making up a kit to cost effectively convert any type 1 air cooled vw engine to EFI without having to cut or physically modify anything.

Here's the basic idea...
Use the original vw intake manifold, bolt on a throttle body with internal injector, use the original 6mm fuel line and a Mexican beetle fuel pump..."

Basically using the same idea shouldnt it be pretty easy? I am a complete newbie on petrol cars and efi-s so maybe I am strongly underestimating the complexity of that kind of project.

User avatar
xantia_v6
Forum Admin Team
Posts: 7217
Joined: 09 Nov 2005, 23:03
x 375

Re: EFI conversion

Post by xantia_v6 »

I did quite a bit of research on EFI conversions a few years ago, but am not familiar with the GSA configuration.

A few points (many of which I am sure you already know):
  • A multipoint system will usually give slightly better starting and running performance than a single point.
  • You can get injector bosses to weld into the manifold tubes, the injectors should be pointing at the back of the inlet valves.
  • You will need to mount a suitable throttle body (perhaps with integral TPS and idle control valve).
  • Any manifold preheating system should be removed.
  • You need a high pressure fuel pump and recirculating fuel system. The pump should be mounted near the tank and no higher than the bottom of the tank. There must be a suitable fuel filter after the pump, and no filter before it.
  • You should fit an inertia cut-off safety switch.
  • Any rubber hoses downstream of the pump (including return hoses) need to be replaced with material rated for EFI pressure.
  • You need to mount a timing wheel and pickup sensor on the crankshaft, or possibly camshaft, this must be mechanically sturdy.
  • You will need to mount an additional engine temperature sensor (not sure where it would go on this engine).
  • You would need to fit a manifold pressure sensor (MAP), unless integrated into the ECU.
  • You will need to mount a 4 cylinder coil block (or 2 double ended coils).
  • Most people fit an oxygen sensor to aid tuning and provide closed loop fuelling operation.
All of those tasks are pretty much mechanical and self evident. Tuning the system is rather more difficult unless someone has already devised maps for a similar engine using similar components. If tuning from scratch you really need time on a rolling road, I have read of people doing it by trial and error on the road, but there would be lots of scope for getting it wrong, and the possibility of damaging the engine with pre-ignition caused by inappropriate fuelling or timing.

User avatar
white exec
Moderating Team
Posts: 5876
Joined: 21 Dec 2015, 13:46
x 960

Re: EFI conversion

Post by white exec »

Am really no expert on this, but I would guess there could be issues with emissions testing.
If OE fitment (eg carburettor), then you could be exempt from later/latest requirements.
If significantly modified, then you might have to meet more recent emissions figures, which could be difficult.

The only way I'd do this was if there were a "bolt-on" EFI option from later vehicles which used the same engine. I'm thinking eg Rover V8 here: originally twin carbs, later an EFI manifold and kit.

Contactless electronic ignition should be easy. Might be worth doing that first, as it will contribute a lot to starting, combustion and low-speed running.

User avatar
Michel
Posts: 1750
Joined: 29 May 2017, 13:50
x 327

Re: EFI conversion

Post by Michel »

http://www.megasquirtuk.co.uk/

You'll need the hardware, as listed by XantiaV6, but the actual ECU and programming/mapping isn't that hard to do with modern kits. You'd be able to run the Ford EDIS ignition system on a GSA 4 pot too, which takes away a lot of the hassle. You'd need to use 1 injector per cylinder on a GS. Getting hold of secondhand manifolds and modifying them is the way to to this.

There's been plenty on the TV on various classic car shows about the advantages (many) and disadvantages (very few) of fitting EFI to classic cars - lower emissions, better economy, better performance and driveability etc..

User avatar
xantia_v6
Forum Admin Team
Posts: 7217
Joined: 09 Nov 2005, 23:03
x 375

Re: EFI conversion

Post by xantia_v6 »

I converted my 1972 E-type to EFI and UK MOT testers never batted an eyelid, nor did they ever actually perform an emissions test.

User avatar
white exec
Moderating Team
Posts: 5876
Joined: 21 Dec 2015, 13:46
x 960

Re: EFI conversion

Post by white exec »

xantia_v6 wrote:
09 Jan 2018, 23:44
I converted my 1972 E-type to EFI and UK MOT testers never batted an eyelid, nor did they ever actually perform an emissions test.
It was probably so well done that they thought it was OE!
How many testers bother to check factory spec for a car, unless there's a glaring issue, or it's a first matriculation/re-registration inspection? Even then...

Raul
Posts: 133
Joined: 05 May 2012, 05:37

Re: EFI conversion

Post by Raul »

I found a link to the multi point injection conversion.
http://eddinsmoto.com/id131.htm

sonoramicommando
Posts: 339
Joined: 07 Sep 2011, 11:03
x 4

Re: EFI conversion

Post by sonoramicommando »

Raul wrote:
10 Jan 2018, 19:29
I found a link to the multi point injection conversion.
http://eddinsmoto.com/id131.htm

Looks like this guy went out of his way to do things the hard way - but that's fine as he has the means to do all the fabrication work himself, which means it didn't cost a lot of money and time.
The question is, do you have all the resources and the knowledge he has at his disposal...
Like others mentioned, most people go for megasquirt as a universal ready made solution, so that's your best bet - I think there are a few Fiat twin cam folks who have done that (having said that, Fiat 124s are pretty popular and numerous in the US).

wurlycorner
Posts: 1402
Joined: 30 Oct 2012, 23:37
x 59

Re: EFI conversion

Post by wurlycorner »

white exec wrote:
09 Jan 2018, 22:26
Am really no expert on this, but I would guess there could be issues with emissions testing.
If OE fitment (eg carburettor), then you could be exempt from later/latest requirements.
If significantly modified, then you might have to meet more recent emissions figures, which could be difficult.


The emissions requirements are done purely on model build year, here (unless you've swapped the engine to one from a different model year and declared it/the MOT tester realises it).

There are plenty of carb classics out there that have had EFI mods done (single point being the most common/simplest). Has no effect on emissions test requirements.

User avatar
Mandrake
Posts: 8097
Joined: 10 Apr 2005, 17:23
x 287

Re: EFI conversion

Post by Mandrake »

Why just convert to fuel injection, why not turbo charge as well! :rofl2:

https://www.youtube.com/user/emknapss/videos

120hp he claims from the dyno run, eg double the original factory horsepower.

Makes a bit of a difference to the acceleration:















Yes, it is a mad Kiwi behind those videos and I don't condone his driving... :twisted:

Great sounding engine with a noisy exhaust fitted I have to say. :-D

Wonder what happened to that car as these videos are over 10 years old now...