Yahoo27

hrmmm, I've been measuring the map sensor signal and it's reading around 2.5 volts but when I have my safc is connected it only reads .5v on the sensor check screen. So your saying the map signal isn't making it to that pin hence it's reading 5volts when everything is connected. Hence it's probably my safc acting as an open to the signal wire, Im pretty sure the ecu can't start the car on the 550s by itself right??

BTW thanks for the quick reply Bug

bugjug

well, i can tell you that for most ECU inputs (but not all) there is a 5v pullup and the ECU measures the voltage divider value of the sensor when it is connected.

Yahoo27

Makes sense, i plugged up the map sensor signal directly to the ecu, reads about 2.6 volts no start prob too rich to start. Put in a gm 3bar had lying around map sensor voltage down to 1.6, no start still prob too rich.

Yahoo27

Ok heres the dealio, Spark plugs fire, I actually poured some gas in the cylinders and it starts and dies, so I feel the injectors and they don't seem to fire when cranking. So I'm guessing the injectors don't open, i checked the resistance in them and they seem to be with in spec. so now what??? ecu signal to injectors? how do i test? ive switched ecus, same symptons

Yahoo27

I'm thinking it's the secondary coil in the igniter where the igf comes out of, so if I had my safc hooked up and the rpm wire is hooked up to the igf and it doesn't register rpm on safc when cranking the motor that means the igniter isn't sending out a igf signal right???? Which won't open my injectors, which explains why it doesn't start right??? Just thinking out loud any confirmation would be great!

Yahoo27

Alright it's not the igniter, I got the right vaccumn reading now. It was the grounds to the safc making it not read right. But the car isn't staying on, it will start and puff puff a lil but doesn't stay on. I'm guessing it shorted out the other grounds or something. What other grounds should i check on the car?? How many grounds is there for the body plugs?