Fuel Economy, Hypermiling, EcoModding News and Forum - EcoModder.com - View Single Post

cmags · 09-23-2008, 02:31 PM

Ok, so I've been having a little bit of difficulty with my MPGuino. Not sure if it's because my car is much newer than most of the cars you folks are installing this in (2005) and has a lot more electronic control, but I've now twice experienced the car start running like crap (idling low, rough, stalling) after disconnecting and reconnecting the neg terminal of the battery with the MPGuino connected. It's like the ECU can't re-learn properly after a reset with the thing connected. The first time, it wouldn't recover until I replaced a nearly dead battery. Was fine for a week until I connected the MPGuino again, and immediately did it again. This time it did recover after a few miles.

So some things I'm thinking of changing, and this is what I'm looking for suggestions regarding. I tapped my injector and VSS signal at the ECU. Should I not tap here and tap directly at the sensor and injector? This will be much harder to do, but I can probably find them.

Second, I had put the 100k resistors on my board, and am now thinking the direct wire tap (about 6' of wire) off the ECU is causing interference. I'm thinking I should move the 100k resistors to right at the tap. My question is whether 200K would be too much for the MPGuino to properly read the signals? If not, I can just add resistors to the taps. If it would be too much, I'll have to re-open the 'guino and short the resistors.

Thanks ahead of time for any suggestions!

09-23-2008, 02:31 PM	#709 (permalink)
cmags EcoModding Apprentice Join Date: Apr 2008 Location: Marietta, GA Posts: 139 Scoob - '05 Subaru Impreza Outback Sport SE 90 day: 25.28 mpg (US) Thanks: 0 Thanked 0 Times in 0 Posts	Ok, so I've been having a little bit of difficulty with my MPGuino. Not sure if it's because my car is much newer than most of the cars you folks are installing this in (2005) and has a lot more electronic control, but I've now twice experienced the car start running like crap (idling low, rough, stalling) after disconnecting and reconnecting the neg terminal of the battery with the MPGuino connected. It's like the ECU can't re-learn properly after a reset with the thing connected. The first time, it wouldn't recover until I replaced a nearly dead battery. Was fine for a week until I connected the MPGuino again, and immediately did it again. This time it did recover after a few miles. So some things I'm thinking of changing, and this is what I'm looking for suggestions regarding. I tapped my injector and VSS signal at the ECU. Should I not tap here and tap directly at the sensor and injector? This will be much harder to do, but I can probably find them. Second, I had put the 100k resistors on my board, and am now thinking the direct wire tap (about 6' of wire) off the ECU is causing interference. I'm thinking I should move the 100k resistors to right at the tap. My question is whether 200K would be too much for the MPGuino to properly read the signals? If not, I can just add resistors to the taps. If it would be too much, I'll have to re-open the 'guino and short the resistors. Thanks ahead of time for any suggestions!