Can a bad engine temp sensor cause a high or changing idle??
Thread Starter
|
Senior User
Joined: Nov 2004
Posts: 163
Likes: 2
Can a bad engine temp sensor cause a high or changing idle??
i have an 86f150 with an 88 fuel injected 4.9l. my truck recently developed a high idle (around 1450 rpm). but sometimes it idles perficlty. as it warms up it seems to get slightly higher. At times it also has a dead spot as soon as i touch the throttle. i have repaced the iac and the tps sensors already in hopes of fixing it. yesterday i scanned it and i got code 21 coolent temp sensor out of range. but my temp gauge works just fine. cold this be the problem?
Posting Guru
Joined: Feb 2006
Posts: 1,448
Likes: 1
The engine coolant temperature sensor is not the gauge sensor. Two different components. The ECT will have two wires, and the gauge will have one wire. The ECT acts kind of like an automatic choke works on a carbed engine. The computer checks the ECT for engine temperature at start up to see if more fuel is needed if the engine is cold, or less fuel if the engine temp is hot. Depending on how the sensor fails, it can cause hard starting when cold, erratic idle, etc., but once the engine is warm the engine starts ok. jd
Thread
Thread Starter
Forum
Replies
Last Post
VR666
1987 - 1996 F150 & Larger F-Series Trucks
13
Jun 16, 2015 11:14 AM
