Question regarding using L-jet on a 2.0

Tidybuoy · 08-24-2009, 08:21 PM

I acquired a 2.0 for my '74 914 which currently has a 1.8.

I understand that the '76 912 uses L-jet on the 2.0 and I'm wondering what is involved in going this route.

I finally replaced everything on my 1.8 (including the injectors) and I hate the thought of having to learn a whole new setup. And, I've heard that D-Jet is fairly primitive - even thought the 914 L-Jet is an old setup and very few sensors compared to a modern system.

Any downfalls from going this route - I'd be interesting in hearing all my options. Any links to good sites would be great too.

Thanks in advance....................Vern

Cevan · 08-25-2009, 11:14 AM

I've asked this same question and have never got a response from someone who actually did it. L-Jet may be primitive compared to today's sytems, but in '74 it was brand new and D-Jet was just about phased out. I also put a 2.0 in my formerly 1.8L 914. I used the D-Jet FI but if it ever craps out, I'll be putting the L-Jet on.

According to this link: http://www.ratwell.com/technical/Injectors.html, the flow rates between the 912E and 914 1.8L are very close. I would imagine some adjusting of the AFM would be needed to get it to run at the proper air/fuel mixture.

Tidybuoy · 08-25-2009, 01:51 PM

It seems to me (and I'm no experet) that because it's a bigger engine, there would be more air being pulled in - the existing 1.8 airflow meter would measure that increased air and send a signal to the injectors to squirt more fuel.

I'm guessing that the 1.8 injectors have limitations on how much fuel can pass thru and maybe the 2.0 needs more than they can provide.

Since the 912e had a 2.0 with L-jet, I would think you could get the stats from that car and incorporate into the 914. I'm just hoping that the computer does not have to be replaced in the process and that it's simply replacing the injectors and possibly changing the fuel pressure.

I'm not sure if the 912e used an oxygen sensor and any othe sensors but I'm going to find out.

Dave at Pelican Parts · Dave at Pelican Parts's Garage

The 912E's L-jet was different from the 1.8's. Almost all of the parts are different.

That said, you can run the 1.8's L-jet on a 2.0 (1971cc) motor. Mike Mueller did so for a while; he reported no problems with it.

I would be worried about pulling more air than the 1.8's AFM can reliably measure. I would invest in some quality dyno time with a wide-band O2 meter, or look into using a stand-alone WBO2 meter and paying attention to it while driving.

--DD

Tidybuoy · 08-25-2009, 10:38 PM

Thanks Dave!