ALFAGTV6.COM

[bmacf]

Hey thanks for the help on the grounds (LJET to MS). I'm still working on my wiring harness, believe it or not. Its ugly as sin!!!

To Michael, I'll take a picture of the under-board diode for the fuel pump circuit as soon as I can.

I'm looking forward to any discussion on using the existing alfa V6 distributor for spark control. Anything not to modify this crank pulley that I paid so much to get and then get balanced!

Thanks,
Bill

[P.Webb]

Bill,

Follow this link:

http://megasquirt.sourceforge.net/msns- ... -msns.html

You use the existing Hall sensor in the Milano distributor and the ignitor shown in the diagram. It replaces the CDI ignitor (amplified) under the coil. You can get one from a 164.

The CDI module is on the passenger kick panel. Take the hall output from it to the MS with the pullup and FIdle out to the ignitor through the same wire as the CDI uses.

Note that the tach in (24) to the MS (pin 1 on L-Jet) comes off the CDI to the L-Jet box. Take the Hall input from the CDI directly into 24 on the MS bypassing the L-Jet wiring, then run the CDI advance out to the FIdle on the MS (pin 30) to pin 6 on the Motronic ignitor.

See the Bosch wiring diagram below.

-Peter

[bmacf]

Fore anybody interested, here are a few more pictures of the alt fuel pump circuit. It works in that the fuel pump runs, but it should shut off after 20 seconds if you don't try to start the car - mine doesn't do that for some reason. I haven't looked into it.

The first picture is the underside diode. The second picture is what you do on top of the board...kinda hard to see. My prior picture of the circuit on the top side is better. The wires for the flyback circuit board are in the way in this picture.




Hope this helps somebody.

Bill

[bmacf]

Hmmmm, you know what, I don't know that my case is grounded. I wonder if that's why the ms box isn't responding anymore. I checked U5 and I have 5V, so I need to go back to the assembly instructions and test all the subsystems.

Thanks for mentioning grounding the case.

Bill

[Michael]

Hey Bill:
Thanks for the pic!
Interesting to hear that your MS stopped responding - mine did much the same last weekend and I really think I have it wired up according to the LJet-->MS Pin-out diagram except that I wired MS pin 28 to LJet pin 28 (instead of 29 as indicated in the diagram).

Anyway, I noticed that when I plugged the board into the Stimulator, one component was getting very hot - U7, the "34151 FET driver - 8 Pin DIP". I ordered a replacement from Digikey and my MS board is working again now that I replaced it! You might want to check yours too, especially if your MS is wired the same way as mine was.

Part numbers from DigiKey are:
IXDI404PI-ND
AE7208-ND (IC SOCKET to make this easier if it happens again).

I'm going to check over the pin-out again and try and find the problem.

Cheers,

[bmacf]

Hey, I figured out why my ms box wasn't running. The processor died. I tested the ms board's power supply and it had 5V at all the right places. I tested the serial communications (no processor, jumper pin 12&13) and it was fine. Then I got to the clock circuit...no response from the processor on the megasquirt software.

For some reason I was given two motorola processors with my order. The power supply circuit seemed fine and there was no other obvious signs of damage, so I plugged in the other processor. When I connected the stimulator, "Voila, ici, la Megasquirt court!" (it runs).

The big question is what caused this. Yes, I had the wrong hookup from MS pin 28 to Ljet pin 29 (should be 28 per discussion above). Another thing is I don't think my MS case is grounded. Both are easily fixed, but does anybody else see a reason why the processor would die other than a potential grounding problem?

For grounding the case, I see that diodes D1 and D2 are unused, and their anodes connect to the MS board's ground plane. I'm thinking of connecting a wire from either of these anodes to the case, internally.

Any feedback would be appreciated. I'd like to get back to tuning this thing according to Peter's suggestions and checking out that ignition project that Peter mentioned above.

Michael, how far are you? Are you tuned and driving yet?

Thanks,
Bill in MD

[bmacf]

Hey everyone, I may have figured out my grounding problem. In following the flyback board instructions, I had incorrectly connected the flyback board ground (-) to the hole for the D4 cathode (barred end) instead of the hole for the D4 anode.

If you follow Steve Rosser's guide, he sais connect the flyback board ground to the case...which I have now done. There should already be a wire from the case to XG1, but I think that has something to do with the tach circuit and not grounding. So I added a ground from the base to the D4 anode, which is the groundplane of the MS board. Now I think I have everything grounded right AND my TPS signal cleaned up too.

If this info is useful to anybody, I can take a picture.

Whew. Next I have to fix my Ljet/MS wire harness per the info on LJeT pin 28 from Michael and Peter. I also might add a dip switch for the BOOT circuit to make it easier to upload code to the chip. Then I button everything back up and get back to tuning.

Whew! Stupid mistakes.

Bill