Vehicle: 1979 Fiat Spider
Engine: 2.0 liter DOHC
Injection: Port injection from a 1980 Fiat
Description: Car originally had a Weber carburetor on it. Replaced this with the L-Jet FI system from a 1980 Fiat. Huge improvement. Replaced L-Jet computer with MegaSquirt V3 board, MII daughter card (running 2.33 firmware) tuning with Megatune 2.5 final release. Everything is fitted into a Motronic ECU box, which is ~compatible with the L-Jet case. A bit of grinding to make things fit nicely + a lot of extra wiring for the connector. Also made an interface cable for L-Jet connector to Stim, which allows the wiring connections to be checked.
Used Peter Floranceâ€™s L-Jet diagram and positive Fuel Pump relay drive circuit. Thank you Peter - that helped a lot. I updated a spreadsheet for Version 3 PCB â€“ Iâ€™ll try to attach it below.
Higher current drive for the PWM Idle driver and V2 flyback diode circuit (TIP120 with a 0.3 ohm current limit transistor). This works on the bench nicely with the VDO 408.202/008/001 PWM idle air valve that I pulled from a SAAB. That unit requires about 1.35A to close. Control range on the idle PWM MegaTune display:
90% starts to open 50% effectively open, 30% completely open. I have not installed the valve in the car yet.
Car started and idled on the first try. Initial VE MAP was drivable. Now tuning, and learning a lot along the way.
Plans for EDIS ignition. All parts are running on the bench â€“ just need to fabricate the trigger wheel and VR sensor holder.
Thanks to all â€“ I wanted to learn more about micro-controllers and practice some process control â€“ this has been an excellent project. I have read (and read) and learned a lot.
i'm just start to install a ms2 on a spider.
ljetronik is died!
i have some questions,are you use the negative coil standard trigger?if yes whats value for r12 ,c12?
do you use standard air and coolant sensor?