Toyota MR2 Message Board - View Single Post

hotwheels · 05-18-2007, 01:45 AM

Ok, so in the last few weeks, my mechanic friend has been helping me run some heavy diagnostics tests on the car.

Testing for Ohms resistence with a good multimeter, when the AFM was unplugged turned up positive results--all 8 nodes within specs. With the AFM plugged in, ohm resistence was good in all but the leftmost two nodes. The specs sheet says there should be no resistence there, but there is--about 300ohms.

This leads me to believe that the resistence is caused by a short somewhere BEFORE the AFM, possibly in the ECU. I am having that checked out at the shop in more detail tomorrow, so I'll let you guys know how it turns out.

Also, is it possible that a mis-adjusted TPS is sending the wrong signal to the ECU, and creating the weird readings in the AFM?

Next, we got on the internet and found some more tests we could do for the high idle. We plugged a multimeter into two particular slots in the diagnostics box. The specs sheet said that once the car starts, the volts should jump up and down like crazy about 8 times, and then settle. When we tried, the volts jumped--0 times, they stayed dead. the internet said if that is the case, to check the plugs, coil, wires, but i have platinum two-electrode racing plugs in there, and i replaced the wires only a few months ago. It also said to replace the ECU if all else fails...(not my favorite idea).

Also, I KNOW that i'm running a rich mixture cuz i can smell gas coming out of the exhaust pipe, and the plugs, three weeks new, are already all black and sooty, not wet, but a dry kind of sooty black color around the electrode.

any brilliant ideas?

05-18-2007, 01:45 AM	#4 (permalink)
hotwheels elvis Join Date: Mar 2007 Posts: 33 Thanks: 3 Thanked 0 Times in 0 Posts iTrader Rating: (0/0% )	Ok, so in the last few weeks, my mechanic friend has been helping me run some heavy diagnostics tests on the car. Testing for Ohms resistence with a good multimeter, when the AFM was unplugged turned up positive results--all 8 nodes within specs. With the AFM plugged in, ohm resistence was good in all but the leftmost two nodes. The specs sheet says there should be no resistence there, but there is--about 300ohms. This leads me to believe that the resistence is caused by a short somewhere BEFORE the AFM, possibly in the ECU. I am having that checked out at the shop in more detail tomorrow, so I'll let you guys know how it turns out. Also, is it possible that a mis-adjusted TPS is sending the wrong signal to the ECU, and creating the weird readings in the AFM? Next, we got on the internet and found some more tests we could do for the high idle. We plugged a multimeter into two particular slots in the diagnostics box. The specs sheet said that once the car starts, the volts should jump up and down like crazy about 8 times, and then settle. When we tried, the volts jumped--0 times, they stayed dead. the internet said if that is the case, to check the plugs, coil, wires, but i have platinum two-electrode racing plugs in there, and i replaced the wires only a few months ago. It also said to replace the ECU if all else fails...(not my favorite idea). Also, I KNOW that i'm running a rich mixture cuz i can smell gas coming out of the exhaust pipe, and the plugs, three weeks new, are already all black and sooty, not wet, but a dry kind of sooty black color around the electrode. any brilliant ideas?