Question about crankshaft sensor
#1
08-20-2012, 10:14 PM
Join Date: Apr 2008
Posts: 102
Likes: 0
Received 0 Likes
on
0 Posts
Question about crankshaft sensor
Where is the crankshaft sensor located on a 97 Discovery?
The Disco runs fine until it reaches a certain temp and will misfire. Won't go over 40 mph. I replaced all plugs and fuel pump to no avail. I will attempt to replace the crankshaft sensor and if that doesn't correct the problem, I'll move to the next one!
Thanks in advance!
The Disco runs fine until it reaches a certain temp and will misfire. Won't go over 40 mph. I replaced all plugs and fuel pump to no avail. I will attempt to replace the crankshaft sensor and if that doesn't correct the problem, I'll move to the next one!
Thanks in advance!
#2
08-20-2012, 10:24 PM
sensor
Its located, faceing the D1 from the front, right side of the engine, on the back of the engine on the bell houseing, oposite of the starter, it will have a small cover over it. Look at the wires from the plug, unplug it, gently pull the wires up from the back of the engine from the wiring harness, that way you dont have to work on your back under the Rover. remove the shielding and see if the wires are bare, replace wires useing close to the same size wireing just not smaller use good butt conectors with shink tubeing and replace the shielding, make sure you clean the conections at the conector. This is a real common problem, just make sure you repace the shielding it gets hot down there!!!!
Last edited by Boggie; 08-20-2012 at 10:26 PM.
#4
08-21-2012, 12:32 AM
Join Date: Apr 2008
Posts: 102
Likes: 0
Received 0 Likes
on
0 Posts
Its located, faceing the D1 from the front, right side of the engine, on the back of the engine on the bell houseing, oposite of the starter, it will have a small cover over it. Look at the wires from the plug, unplug it, gently pull the wires up from the back of the engine from the wiring harness, that way you dont have to work on your back under the Rover. remove the shielding and see if the wires are bare, replace wires useing close to the same size wireing just not smaller use good butt conectors with shink tubeing and replace the shielding, make sure you clean the conections at the conector. This is a real common problem, just make sure you repace the shielding it gets hot down there!!!!
Thanks
#5
08-21-2012, 04:43 AM
Super Moderator
And the codes were?
May not be CKP, when it fails more normal to have no start (no spark) or won't start back when engine is hot. TPS can make engine run only to about 1700 rpm as an example. Here are some drawings and info on the CKP, be sure every little nut and spacer goes back in same sequence, alignment is super critical. Easier to plug in and let it dangle before mounting.
Might try reseating plugs on other sensors.
If revs up ok when parked, and will run at elevated rpms, like 2000, etc., and only does this while driving may consider the VSS which is on the transfer case and signals speed. When it goes whacko it tells the ECU you are trying to drive over 115 mph (or close) and the limiter function comes in and cuts engine performance.
May not be CKP, when it fails more normal to have no start (no spark) or won't start back when engine is hot. TPS can make engine run only to about 1700 rpm as an example. Here are some drawings and info on the CKP, be sure every little nut and spacer goes back in same sequence, alignment is super critical. Easier to plug in and let it dangle before mounting.
Might try reseating plugs on other sensors.
If revs up ok when parked, and will run at elevated rpms, like 2000, etc., and only does this while driving may consider the VSS which is on the transfer case and signals speed. When it goes whacko it tells the ECU you are trying to drive over 115 mph (or close) and the limiter function comes in and cuts engine performance.
#6
08-21-2012, 01:08 PM
Baja
Join Date: Mar 2010
Location: Pittsburgh PA suburbs.
Posts: 5,584
Likes: 0
Received 7 Likes
on
7 Posts
Its located, faceing the D1 from the front, right side of the engine, on the back of the engine on the bell houseing, oposite of the starter, it will have a small cover over it. Look at the wires from the plug, unplug it, gently pull the wires up from the back of the engine from the wiring harness, that way you dont have to work on your back under the Rover. remove the shielding and see if the wires are bare, replace wires useing close to the same size wireing just not smaller use good butt conectors with shink tubeing and replace the shielding, make sure you clean the conections at the conector. This is a real common problem, just make sure you repace the shielding it gets hot down there!!!!
So you advocate good butt connectors and shrink tubing...Hmmm....
Very interesting....
#7
08-21-2012, 01:58 PM
Super Moderator
#8
08-21-2012, 08:40 PM
Where is the crankshaft sensor located on a 97 Discovery?
The Disco runs fine until it reaches a certain temp and will misfire. Won't go over 40 mph. I replaced all plugs and fuel pump to no avail. I will attempt to replace the crankshaft sensor and if that doesn't correct the problem, I'll move to the next one!
Thanks in advance!
The Disco runs fine until it reaches a certain temp and will misfire. Won't go over 40 mph. I replaced all plugs and fuel pump to no avail. I will attempt to replace the crankshaft sensor and if that doesn't correct the problem, I'll move to the next one!
Thanks in advance!
You were going to throw parts at it until you got lucky?
With the direction you were heading someone else would have bought a almost new truck for cheap when you finally gave up and sold it for the first offer over $100.
VSS, vehicle speed sensor, it is the trucks speed limiter, it kills spark to the engine to slow you down, when it acts up it kills spark anytime it wants, usually under load, like when trying to accelerate or climb a hill.
You usually get multiple cylinder and random cylinder misfire codes.
It is about a $150 part, about 30min to replace.
I'm not trying to be a jerk, just honest.
You should have asked before throwing $1000 at it in parts.
Last edited by Spike555; 08-21-2012 at 09:59 PM.
#9
04-13-2013, 09:19 AM
#10
04-13-2013, 10:24 AM
Super Moderator
Here is some text on open loop.
Attached is the GEMS engine computer book which lists the codes and what triggers them in greater detail. I would be concerned about staying in open loop (low mpg), but going in/out of open loop is normal depending on driving habits.
As a test, you can unplug the VSS sensor to rule it out, truck will drive, no cruise, and speedometer will be dead.
OPEN AND CLOSED LOOP OPERATION
CLOSED LOOP OPERATION
During closed loop, or feedback operation, the ECM controls fuel system operation based on
information provided by the various vehicle inputs. Because these inputs represent actual
operating conditions, the system is most able to meet performance and efficiency targets when
operating in closed loop.
The primary input during closed loop operation is the oxygen sensor since it indicates the result
of the combustion process, regardless of the engine speed and load.
The primary output during closed loop operation is the fuel injector timing and duration.
All other sensors generally serve to help the ECM ‘trim’ or anticipate the operation of the engine
to meet a particular oxygen sensor value or known tailpipe emission condition.
OPEN LOOP OPERATION
At times (start-up, full throttle) engine operating requirements may fall outside the bounds of
that suggested by the ECM inputs. Some sensors do not operate at peak efficiently until warm.
At these times, the ECM substitutes a pre-programmed set of reference inputs that are most
likely to produce desired engine operation. This is referred to as open loop operation.
The system may also default to open loop operation when component failure provides an input
signal outside the range of known parameters recognized by the ECM. The ECM will substitute
a signal value that allows the vehicle to continue to operate. The Malfunction Indicator Lamp
(CHECK ENGINE) on the instrument panel is illuminated at this time to indicate the failure of an
emissions-related component.CLOSED LOOP OPERATION
During closed loop, or feedback operation, the ECM controls fuel system operation based on
information provided by the various vehicle inputs. Because these inputs represent actual
operating conditions, the system is most able to meet performance and efficiency targets when
operating in closed loop.
The primary input during closed loop operation is the oxygen sensor since it indicates the result
of the combustion process, regardless of the engine speed and load.
The primary output during closed loop operation is the fuel injector timing and duration.
All other sensors generally serve to help the ECM ‘trim’ or anticipate the operation of the engine
to meet a particular oxygen sensor value or known tailpipe emission condition.
OPEN LOOP OPERATION
At times (start-up, full throttle) engine operating requirements may fall outside the bounds of
that suggested by the ECM inputs. Some sensors do not operate at peak efficiently until warm.
At these times, the ECM substitutes a pre-programmed set of reference inputs that are most
likely to produce desired engine operation. This is referred to as open loop operation.
The system may also default to open loop operation when component failure provides an input
signal outside the range of known parameters recognized by the ECM. The ECM will substitute
a signal value that allows the vehicle to continue to operate. The Malfunction Indicator Lamp
(CHECK ENGINE) on the instrument panel is illuminated at this time to indicate the failure of an
Attached is the GEMS engine computer book which lists the codes and what triggers them in greater detail. I would be concerned about staying in open loop (low mpg), but going in/out of open loop is normal depending on driving habits.
As a test, you can unplug the VSS sensor to rule it out, truck will drive, no cruise, and speedometer will be dead.