ACT vs. ECT???
Thread Starter
|
Senior User
Joined: Mar 2000
Posts: 358
Likes: 1
From: Tri-Cities, WA
ACT vs. ECT???
I may have recently tested the wrong sensor, although according to the Ford Fuel Injection website they should spec out exactly the same... Anyhow, is there a simple way to tell which is which without pulling them out of the intake manifold? One is closer to the front of the motor than the other, but which is which???
Thread Starter
|
Senior User
Joined: Mar 2000
Posts: 358
Likes: 1
From: Tri-Cities, WA
I'll take a closer look tonight, as I was working with my Maglite in the dark last night... But, from what I could see for sure, there were (2) very similar looking sensors not even 3" away from each other, both mounted vertical, both at the FL area of the manifold.
Fleet Owner
Joined: Aug 2005
Posts: 23,666
Likes: 301
From: Easton,Ks
Originally Posted by tobyw
I may have recently tested the wrong sensor, although according to the Ford Fuel Injection website they should spec out exactly the same... Anyhow, is there a simple way to tell which is which without pulling them out of the intake manifold? One is closer to the front of the motor than the other, but which is which???
/
Last edited by subford; Nov 16, 2007 at 06:17 PM.
Thread Starter
|
Senior User
Joined: Mar 2000
Posts: 358
Likes: 1
From: Tri-Cities, WA
Excellent graphic subford , much appreciated!! Trouble is, it confirms I tested the wrong one 
Why does the one I want to test have to be tougher to access?!!! [/rant]
Just out of curiosity, how grossly do the ECT and/or ACT reading affect fuel mixture? And what is "normally" seen in terms of the resistance readings if one of them is bad? Would it have infinite resistance, or be off by a percentage margin, or ???
Why does the one I want to test have to be tougher to access?!!! [/rant]Just out of curiosity, how grossly do the ECT and/or ACT reading affect fuel mixture? And what is "normally" seen in terms of the resistance readings if one of them is bad? Would it have infinite resistance, or be off by a percentage margin, or ???
Posting Guru
Joined: Jan 2006
Posts: 1,263
Likes: 1
From: The dark carnival
It should be self explanatory which is for air and which is for coolant. You can see where the thermostat sits and that passage is needless to say for coolant. The passages on the side of the manifold is where the air enters the heads. Fairly cut and dry.
The temp sensors play a huge role in fuel trim. A bad coolant temp sensor can turn any motor into a total gas hog.
If you want to test it you need to get a temp reading of the coolant then check the voltage signal that it is sending to the computer. Compare that signal to specs given here: http://fordfuelinjection.com/index.php?p=28 If it does not spec out, you have a problem. This is most easily done with a laser thermometer and a scanner / breakout box / monitor. Back probing is a joke.
The temp sensors play a huge role in fuel trim. A bad coolant temp sensor can turn any motor into a total gas hog.
If you want to test it you need to get a temp reading of the coolant then check the voltage signal that it is sending to the computer. Compare that signal to specs given here: http://fordfuelinjection.com/index.php?p=28 If it does not spec out, you have a problem. This is most easily done with a laser thermometer and a scanner / breakout box / monitor. Back probing is a joke.
Thread Starter
|
Senior User
Joined: Mar 2000
Posts: 358
Likes: 1
From: Tri-Cities, WA
Is the resistance across the terminals of the sensor reliable compared to the voltage readings? It seems much easier to simply unplug the harness and use the DVM to measure the resistance against the chart on the Ford Fuel Injection chart...
As for temp checks, I've already got an Autometer water temp guage installed so I have a reasonable idea what the actual temp is...
You mention the ECT having a great affect on the fuel mixture, which I can totally understand. But what does a bad ECT normally react like when checked out? For example, if it ramps down in Kohms at a rate that compares to the chart, but actually reads 12Kohms at 200degrees instead of the specificed 2Kohms, is it time to swap it out or is that acceptable?
Also, what about this ACT/IAT sensors effect on mixture?
As for temp checks, I've already got an Autometer water temp guage installed so I have a reasonable idea what the actual temp is...
You mention the ECT having a great affect on the fuel mixture, which I can totally understand. But what does a bad ECT normally react like when checked out? For example, if it ramps down in Kohms at a rate that compares to the chart, but actually reads 12Kohms at 200degrees instead of the specificed 2Kohms, is it time to swap it out or is that acceptable?
Also, what about this ACT/IAT sensors effect on mixture?
Trending Topics
Elder User
Joined: Jun 2006
Posts: 805
Likes: 3
12K is way too high. It should be throwing a code that high, because it will be even higher at lower temperatures. If the ECT fails, the ECM will go to "Limp Mode" dumping horrendous amounts of fuel into the engine just to keep it running at any throttle position. This is so you can make it home if it fails out on the highway. Mine died when my truck was about 3 years old, and I burned nearly 3/4 tank in a 90 mile trip, and looked like a coal fired locomotive coming down the road.
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
10 Best Ford Truck Engines We Miss the Most!
Joe Kucinski
2026 Shelby F-150 Off-Road: Better Than a Raptor R?
Brett Foote
2027 Super Duty Carhartt Package First Look: 12 Things You NEED to Know!
Michael S. Palmer
10 Most Surprising 2026 Ford Truck Features!
Joe Kucinski
Top 10 Ford Trucks Coming to Mecum Indy 2026
Brett Foote
5 Best / 5 Worst Ford Truck Wheels of All Time
Joe Kucinski
Ford Super Duty: 5 Things Owners LOVE, 5 Things They LOATHE!
Joe Kucinski
Every 2026 Ford Truck Engine RANKED from WORST to FIRST!
Michael S. Palmer
The Best F-150 Deal of Every Trim Level (XL through Raptor)
Joe Kucinski
Thread
Thread Starter
Forum
Replies
Last Post
Trigger200
1997 - 2003 F150
5
Jun 7, 2009 05:27 PM
JBronco
1978 - 1996 Big Bronco
3
Oct 5, 2002 03:31 PM
