Intermittent Hall Sensor
Thread Starter
Advanced
Joined: May 2008
Posts: 56
Likes: 3
Intermittent Hall Sensor
My check engine light has been coming on lately. After pulling the code, I found out that it was the Hall sensor that was producing the signal. Went onto the forum and looked up possibilities, the main one being spark discharge. So I went out in the dark of night with my trusty water spray bottle to discover the spark source – no engine sparks or discharges were seen (admittedly, I did not look at the wires under the engine). Here’s the real kicker: the check engine light does not come on all of the time, it usually, but not always, comes on when the ambient temperature is low (in the 30s) and stays on for the duration of the drive. Of course, when the light doesn’t come on, either on initial morning start or usually later in the day when the car has been sitting some hours, the car runs fine. When the check engine light is on, the car won’t idle correctly (usually stalling out) and, upon pressing the accelerator pedal too much, the engine will stumble – this occurs in all gears. Anybody out there have any ideas as to what is failing?
Instructor
Joined: Jan 2008
Posts: 109
Likes: 1
From: London
Try cleaning the contacts on the hall sender connection on the side of the distributor. The wiring can get quite hard with all the heat generated so don't pull the connector back too far. If that doesn't work, clean up the contacts on the dme controler under the front seat.
Burning Brakes
Joined: Jun 2004
Posts: 762
Likes: 10
I'd guess bad plug wires. When was the last time they were changed? If you start the car at night or in a dark place, and then while it's idling you lightly mist the engine bay, you might see arcing around a plug wire or two if there is a problem.
Rennlist Member
Joined: Aug 2007
Posts: 906
Likes: 28
From: Cape Cod, Ma
Did you check to see if there was any sparking at the coils? Hard to do with coil covers on. I would also check grounds. If the coils are old & never been changed (even if they test within spec's) they can cause this type of problem.
Thread Starter
Advanced
Joined: May 2008
Posts: 56
Likes: 3
Thanks gents. I did use the misting at night w no results. However I didn't take off the coil covers, so I'll try that. I have no idea when the plug wires were changed; they may be original. What is extremely puzzling to me is the intermittent nature of this problem. Sometimes the check engine light comes on and sometimes it doesn't for days. Go figure.
