Testing coils on a coil over plug system?

Ed Wright · 09-12-2011, 07:06 PM

Al, make bigger fuel pressure changes. It doesn't drop cylinders? Just dies? If it does not drop cylinders it sounds rich to me. Like Joe said, the coolant temp sensor may be out of calibration. Usually if one is too lean to idle in gear they will surge some in neutral. If you have an open in the coolant temp sensor or it's circuit the ECU will consider that -40 deg F. If that ECU has a scan function check that out. If it shows -40, take a piece of a paper clip and jumper the 2 pins in the coolant temp connector. You should then see something like 300 + deg F. If you it's the sensor. If not it is a wiring issue.

09-12-2011, 07:06 PM	#9
Ed Wright Veteran Member Join Date: Mar 2005 Location: Sand Springs, OK Posts: 8,132 Likes: 896 Liked 390 Times in 170 Posts	Re: Testing coils on a coil over plug system? Al, make bigger fuel pressure changes. It doesn't drop cylinders? Just dies? If it does not drop cylinders it sounds rich to me. Like Joe said, the coolant temp sensor may be out of calibration. Usually if one is too lean to idle in gear they will surge some in neutral. If you have an open in the coolant temp sensor or it's circuit the ECU will consider that -40 deg F. If that ECU has a scan function check that out. If it shows -40, take a piece of a paper clip and jumper the 2 pins in the coolant temp connector. You should then see something like 300 + deg F. If you it's the sensor. If not it is a wiring issue. __________________ Ed Wright 4156 SS/JA