TBI to semi-sequential MPI (VW Passat)
Posted: Sun Oct 30, 2011 1:22 pm
Hi,
this is our MY88 VW Passat Variant family hauler powered by the unbreakable 1.8L 90hp TBI engine, 300Tkm on the odometer.
The car itself is uninteresting, but the conversion might be of interest to those of you who want to convert a TBI engine like the 305 OR 350 Chevys from the early 90ies using a sequential system.
Basically, all 4 petrol Injector hookups were soldered together, so the LPG controller handles the signal as it would handle a full-group system.
My favorite LPG controller, the AC Stag 300 has an option to drive the LPG injectors semi-sequentially on full-group petrol systems. This means the frequency is split into half, the injection time is doubled, plus on that particular inline four the LPG injectors are grouped in 2x2, 2 firing at the same time. An important feature, as the petrol injection time is 1.7ms at idle on that Bosch Mono-Jetronic single injector, and no known LPG injector can handle that.
Stag connection schematics
this is our MY88 VW Passat Variant family hauler powered by the unbreakable 1.8L 90hp TBI engine, 300Tkm on the odometer.
The car itself is uninteresting, but the conversion might be of interest to those of you who want to convert a TBI engine like the 305 OR 350 Chevys from the early 90ies using a sequential system.
Basically, all 4 petrol Injector hookups were soldered together, so the LPG controller handles the signal as it would handle a full-group system.
My favorite LPG controller, the AC Stag 300 has an option to drive the LPG injectors semi-sequentially on full-group petrol systems. This means the frequency is split into half, the injection time is doubled, plus on that particular inline four the LPG injectors are grouped in 2x2, 2 firing at the same time. An important feature, as the petrol injection time is 1.7ms at idle on that Bosch Mono-Jetronic single injector, and no known LPG injector can handle that.
Stag connection schematics