L jetronic / inertia switch

[MNspiderman]

i'm wondering that myself mark

[MNspiderman]

my next unhappy thought is this.
so the two white wires going to the safety switch are dead. But the fuel pump will work. ok. so that mean to me that somehow, somewhere this PO has torn off the white wire that goes to the fuel pump, disconnected the 12v supply to the white wires somewhere in the car, rendering the safety switch dead, and did his own wiring to make the pump shut off and turn on and this might be why he jumped the fuel pump switch in the afm and added his own special relay. Hmmmmm. could be possible in my unelectricalknowledgable world. This sounds like a possibility. Ok, I have some photos that i posted on the other website. take a lookski. You'll see what i mean.

[pope]

I think that half of the dual relay does not work. It is the pump half, that has the thicker (power) wires going in. All this guy did was add a relay before the pump relay in the dual. 88y is the fuel pump feed. What this does is bypass the ignition start function to start the fuel pump.
Like Mark said, I would suggest tearing out all this PO stuff, and make sure that wires are where they are suppose to go. Will be a lot easier to diagnose from there.


The fourth pic with the black box that you labled safety switch, should be the lambda reset box. Unless the words are just generic for the whole pic and not specific to the black box

The only relay for the ignition is the dual relay.

You are thinking about this all wrong. The pump gets it own power. The entire fuel injection system gets its power (only from the dual relay). NO OTHER SOURCE! The pump has its own power supply, but goes throught the dual relay so the ignition can control start and the AFM can control accident shutoff. Dont look for power sources under the dash or any where else, there are none.

You say that one of the white wires goes to 88d? That should not be. 88d is a direct power source for the fuel pump. Straight from the relay to the pump. The wires from the AFM go to 88a and 86b

[MNspiderman]

dont forget POPE this is my alfa GTV6 not a FIAT. Even in the service manual. It shows the white wire coming off of 88d making a direct route into the fuel shut off safety switch (you can physically see this) and then it continues right back up itself (as seen in the photo) but dives into the wiring harness which then supposedly goes right to the fuel pump. But one of my problems is that circuit is dead. Well tonight I jack up the car and see where the fuel pump wires run too. My fuel pump is in front of the back tire. I was following a Porsche L jetronic help pdf, it was terrific then i noticed that such things like the afm wires have different pin numbers. such as my fuel switch numbers are 36 and 39 and porsche is something else. but it gave me great ideas. I assume fiat is kinda the same way. Its all the same but a little bit different. the L jetronic porsche combi relay looks the same but all the 88's, 85's and 86's are in different locations, not to mention i had more wires than the porsche in my combi relay. But I will get this thing to work. Ya know my contact points are voltless in my afm with the key forward. and where this guy piggybacked that extra relay. one of the wires he tapped into was yellow and red, #85 on my relay. Its in the photo. Well last night I discovered that if i apply a ground wire to the orange/red #85 that now my contact points in my afm become alive again. Go figure... Maybe i need to do a continuity test on 85 and see if it goes to the ecu or somewhere else. I often wonder if a bad ecu can be doing this. maybe someone put cables on the battery backwards once upon a time. I wish there was a way to test an ecu. without buying another one. any ideas? Actually my wiring diagram does tell me that terminal 85 does go to pin 26 on my ecu. but that is the end of the information highway in my book. All wires eventually lead to the ecu is what i am gathering.

[rlux4]

And it bears repeating, as Pope said ealier, white wires are ground. No white wire on the car will be hot.
It seems that you don't have Brad Artigue's wiring diagrams. Unfotunately, his site is down for a while and I don't have them on my computer. Blown up for clear viewing his diagrams are indispensible.
Ron

[MNspiderman]

Alright, I will look into the white wire further. I don't disagree with anyone so I will take all advice. I guess i should do a continuity test on that one too just to see if it is hooked up. Or maybe i can wack it with a hammer and get it to pop and see if my fuel pump really does shut off. There will be no denying if it hooked up or not.

[pope]

The L-jet manuals I have are from Bosch and are not car specific. They dont mention Fiat or anyone other car in them. They only talk about the system from Bosch. This happens to be exactly how Fiat implemented the system.
I notice that the red wires coming from the dual relay are all white on the Fiats.
Its the little details that are going to cause a pain.

I am glad that Fiat didnt want to spend any more engineering dollars on the Spider and just went with the off the shelf L-Jet system.
The more I think about this, I dont think you have an L-Jet system in there. Bosch made many varients of the system.
They made the LE 1-Jetronic, LE 2-Jetronic, LE 3-Jetronic, LU-Jetronic, and LH-Jetronic. Some of these systems put control of the fuel pump on the AFM.
See if you can find out exactly which system you have.

[rlux4]

Good eye Pope. I was wondering why I didn't see the brown w/ white stripe or the green w/ black stripe wires. And the large brown one for that matter. If that's the case, a wiring diagram is going to need a lot of translation.
Ron

[MNspiderman]

Here is what i was told about the white wires when I mentioned that they are ground wires on the alfa site.

WHOA!!!

You were told the inertia switch wires are grounds? I beg to differ! The inertia switch resides between combi relay output 88d and the fuel pump and interrupts the POWER circuit to the pump, not the ground.

So this is where I my information that this man said those whites are suppose to be a power line with an inertia switch in the middle in case of an accident. He is an alfa racer. So i think once again that the fiat and alfa L jetronic's are a bit different when it comes to wiring. might be the same parts.

[pope]

Looks like there is a change in the L-jet for the Alfas then.
Maybe this will help though.

http://alfagtv6.com/pdf/bosch_tuneup.pdf