Fuel Injector Adapters

[Fylnn]

My GTV6 2.5 is running a Haltech computer.  It does struggle to run the old style low impedance injectors.  The higher current on these sometimes causes the computer to go into a protection mode for a few seconds when things overheat, then it restores power.  Being a gravel rally car, this is not that desirable since it tends to occur every so often but when you have been giving it the beans.  I see it maybe once or twice a rally. 

Anyway I thought I would be a clever dick and upgrade to the later style high impedance injectors, so I got a set of adapters from Performatek in the US (subsequently found same thing cheaper in EFI Hardware site locally) and some injectors and went about swapping them over.  But with the injector and the adapter and the barbed ends, the fuel rail now sits about 10mm higher which is enough to now prevent the plenum chamber sitting in its original spot.  Options being apparently to cut longer inlet runner hoses or somehow lower the fuel rail.  Since the barb on the fuel rail is now hard up against the barb on the adapter, not much chop there.  Not entirely keen on raising the plenum chamber although it looks like it can fit.

But really the whole adapter and barb thing is a band aid.  I probably should put this on the 164 section, but does anyone know when the V6 went to the later style injectors?  I thought it was with the Motronic in the 164.  If so they appear to be a proper fuel rail for this later style injector.  I am assuming the head had a different casting with a mounting somewhere for the fuel rails.

Anyone come across this before during engine swaps etc?

[Fylnn]

Added photo of what I am talking about

[Cool Jesus]

I think the 164 changed injectors around late '92, '93 when the Q4 or 24 valve engine was introduced. Apart from performance and ecu changes, the injectors changed due to the 24 valve configuration of the heads, hence air tubes and injectors needed re configuring. Even so, why stick with Alfa injectors? I'm looking at alternative, bigger flowing injectors for my track Alfa 164 and if my memory serves me well. I believe the Saab 'red tops' look to be a straight swap. I'll see if I can add ta pdf I have for injectors, as it appears that the part numbers don't seem to change for the 164, although they do differ between the GTV-164. I've also included a web page which you may find useful. It shows all the specs for injectors and you may be able to match a more appropriate injector to your fuel management?

http://users.erols.com/srweiss/tableifc.htm

[Cool Jesus]

Better still just found that the webiste has a PDF version

[Fylnn]

Thanks, that is good information.  I have already upgraded the injectors, they are now slightly larger units, but Bosch, not standard Alfa, which were Bosch anyway.  It is just that the later style have the different connection, so either got to put on adaptors which I have with a bit of hose and hose clamps, or look at the later fuel rails which would just push onto the o-ring.

Then the whole arrangement sits down lower and I can get the plenum chamber back on.

[Steve S]

You may not wish to hear it but you could of used a resistor in the circuit to please the ECU.

[Fylnn]

It already has a resistor in the circuit, supposed to drop it to 9V.  Works most of the time, but only has issue when giving it the beans on rally stages.  But the whole point is to do that.

I think what i need is a set of 164 fuel rails for the push on connection for the o-ring.  Will have to poke around sometime and find some and work out what is needed to be modified to make them fit.  For now though might just live with it until after the next rally and in meantime put a cooling fan on the computer cover to see if that helps.