Hi all, I'm troubleshooting an electrical problem on the car, which led me to pull the panel in the truck and take a look at the XDI wiring. I'm pretty sure I've seen a rat make a cleaner nest, and certainly with less electrical tape. The main harness is also interesting, as 2 pins that are supposed to be connected (according to manual) ... aren't connected. Anyhow. I've downloaded the Electromotive manual, but cannot determine the function/purpose of this box. (It comes with the Forza kit.) Need to know what the box does, what the 3 wires are for, etc etc. You can see that the installer simply hacked up the old AMP connectors and spliced them in, so I'm not sure what I can cut, redo, or delete. Help? Thanks. Image Unavailable, Please Login
Update: Have determined it has something to do with the tachometer. Still unsure of the 3 wires' designations, though WHITE appears to possibly be 12V power.
Its for the tachometer. Brown wire goes to plug J1, pin 18. Black is ground See the included diagrams I mounted my XDI vertically to a metal board. If you put it flat on the floor to the left, that's one of the lowest points in the trunk and water can accumulate there. Sometimes the water comes in from the taillights rubber to body seal. I usually put a thin bead of butyl rubber sealant between the body and the twilight rubber to fill the spaces and make it water tight. Go easy when tightening the studs that secure the taillights or els the stud will pull out from the plastic taillight. Here is my set-up
You completely rock - that info is exactly what I needed. The pics and PDF are also great to have. Seriously, thank you. (BTW, seriously envious of that clean install)
You are welcome. Lots of good advice on the board. When I got my XDI kit, I was overwhelmed. I spent many a night studying diagrams and figuring out what went where and how I would mount it. The XDI for carb cars really make a difference. I did find I needed more advance than initially thought. I used the Advance Output wire (pink, pin 21 on the XDI) and ground that can connect to a multi meter to get an exact advance reading. The adjustment knobs are good, but the wire and multimeter is precise. I also tuned it on a dyno to finalize the total advance. I remember reading that the Weber carbs like a lot of initial advance. I think my total advance was around 42 degrees.
Never heard about a gas tank ground. Nick does recommend a wire direct to the battery for 12V. I ran a power wire from the starter to my 12V distribution strip. I grounded my coils to a bolt that secures the starter then ran a new ground strap from there to a point on the chassis. Make sure you use a heavy gauge wire, #10, I think.
I've got the 2 coils mounted with 18 gauge wire+ring terminal to the gas tank, sharing the ground (for the gas level sender, I'm guessing. Not exactly a big amp draw ground...) I've never seen it done in such a ... creative way, so just wanted to toss it out there. I'm cutting new cable for a new location as we speak.
Old ground wires... snazzy, right? New 10ga grounds bolted to the frame. So far the car now starts almost instantly, instead of haltingly coming to life after 2 key cycles. We'll see if it's truly resolved once the weather clears up for a long drive. Image Unavailable, Please Login
Every time I log on you or tackling another project. Always well documented and step-by-step “how to” for future users. But you’re making us procrastinators look very very bad!
I also have installed the Forza Ferrai XDI system, to replace my old HDX, which gave up after 16 years of great service. I have very poor acceleration and it appears as if the advance curve is not adequate for the demands of the engine. I have checked and double-checked all my connections and grounds, and have new spark plugs, and plug wires. My sensor is at the trailing edge of the 11th tooth, and I am stumped. I am considering the optional MAP vacuum advance optional unit, but Nick does not support it. If anyone can recommend the settings of the timing for the 83 308 GTSI QV, I would be appreciative, as well as for any other advice, especially on the MAP unit. Thank you.
Yes, and the multimeter confirms the proper voltage, at the corresponding RPM. I have contacted Electromotive, and they agree to have the unit sent to them for bench testing. My previous setup was the HDX earlier system. It did have the vacuum advance feature, and I am thinking of ordering it from Electromotive once the diagnosis of the processor is done.
