Tampa 928s

78 5-speed
Does anyone have a list or parts required to convert a 78 to l-jet?
So far I see the following is required.

Water bridge
Inj harness
Fuel lines
Pressure regulator and dampener
Air box
ECM
Intake tubes
Injectors "what size"?

How about the CE panel and relays?
Any other wiring?
Other parts?

Koenig-Specials 928

Maybe a huge & costly undertaking. Are you going to use an old inj and ECM harnesses that's already seen its active life or ECM ? Why not simply go with one of the cheaper and simpler aftermarket engine management systems such as Acel or Holley (quite a few more out there) that will come with new harnesses etc. and its own logic instead of re-configuring the Porsche logic to work with your mod.

Just saying!

Tampa 928s

I have access to all the parts or at least the parts I know are required. This is a father and son project and the direction I want to take.
The undertaking is not as bad as you describe and very doable so my previous ? Stands.

FBIII

The worst part is changing over all the fuel lines from the tank forward. CIS uses two lines Ljet runs four or five. Some can be changed without cutting some have to be cut to be removed. Years ago I put an 84 US engine in an 80 Euro s. I used the 84 control panel and the only issue I had is I wasn't getting 12 volts to the injectors. I ended up having to supply 12 volts to one of the relays to get it to run.

Ducman82

might be worth it to look in to going to a stand alone ECM, like Mega Squirt at this point.

toofast928

Tampa consider what Frank is saying.
L-Jet is a nice system but your going to be building the wire harness anyway. Consider Meagasquirt, Hatech or any of the others. You can have a MAF system for under 1-1.5k.

With the benefits of data recording, having the ECU control engine fans, warm up valve, AC idle up, shift light, etc. Total AN fuel system use any injector you wish with the bling.
Also more power with using MDS box and controlling the ignition map. Your still supercharged right? So much can be unleashed with aftermarket EMS.

If you wish I have a lot of the L-jet system in the shed. I know i have the AFM, ECU and fuel dampers/reg. and fuel lines.

Tony

Tampa 928s

78 with custom S-4 body kit, nice racing seats, interior crap needs fiberglass needs work and paint.

I have the wiring harness off of an 82 this is the first I heard of the fuel lines.
This is a bare bones budget my son and I just ran through a 88 924s 49k miles lots of new parts he just turned 17. This will be his upgrade it needs a lot of work and money is at a premium.

When we recived the car or ran like crap, P.O. Had taken apart every part of the CIS system after he purchased it due to not going over 3k. I have tried several Wur and got the pressures to be within specs. As it warms up it goes to 2k starting is fine finally and goes to red line. I smoked it check everything several times I am at a loss.
I was told this was very doable if I was were to spend money on an after market management system I I would put it in my S/C 86.
Seems like the fuel line needs more research, has anyone actually done this?

FBIII

I told you the fuel lines were required because I did exactly what you're contemplating.

Jeff Bowlsby

Not sure where that came from. L-Jet has 2 fuel lines. Supply and return, at least the 1981 USA model does.

FBIII

The 84 had the fuel cooler tied into the a/c system. Possibly the reason for the extra lines.

danglerb

Seems like I have heard this game plan before, can't get the stock system working well, so to save money plan on swapping in something else. On the bright side you could be the first to make it work.

Tampa 928s

I am really frustrated with the Cis I parked it and maybe ready soon to see what I can find. Maybe not giving up on this and spending a little more time is the way to go.

James Bailey

OK, so is your only problem the too high an Idle speed (2000 RPM) when warm ??? Otherwise it starts fine and will pull to redline...

Tampa 928s

I have not driven this car yet but at idle it would not go over 3k when I adjusted the wur it now will red line. It starts fine idles at 1k as it warms up it goes to 2k. I have smoked it and no leaks going to look into the iac as a possible issue.

James Bailey

OK you are not that far away from having it drivable... does it still have the deceleration vacuum limiter on the side of the throttle body ...the yellow metal can with two short hoses ?
And the small solenoid mounted to the fender crossbar which opens with the A/C compressor to raise the idle look for the two braided hoses which go to the intake ? Both of these bypass the butterfly.....