1995 xjs 4.0l aj16
#1
05-03-2017, 08:53 PM
#2
05-04-2017, 07:17 AM
Veteran Member
1. Clean the throttle body. It is probably sticky with old oil residue. That's the most common issue.
The rest of my recommendations are gonna have to do with the interesting point of your problem occurring with a warm engine. That means something is wrong with the closed loop operation of the engine.
the 4 biggest contributors to the fueling of your engine in closed loop is:
1. Coolant Temp Sensor
2. Oxygen Sensors
3. MAF sensor
4. I forgot the last one....dammit! I'll come back and edit this post when I recall. you can search my posts as well.
I'd begin with the cheapest and easiest item, the coolant temp sensor.
then, I would replace all four oxygen sensors, they're probably well overdue if they're originals.
the MAF sensor is typically the least likely, and most costly to replace.
i wanna say the fourth one is the TPS. Throttle Potentiometer Sensor. That's another costly, but more likely problem. for your problem, there's a way to test the TPS by checking the voltage reading at idle from two of the three wires. I believe you want to see a 0.6v Reading.
The rest of my recommendations are gonna have to do with the interesting point of your problem occurring with a warm engine. That means something is wrong with the closed loop operation of the engine.
the 4 biggest contributors to the fueling of your engine in closed loop is:
1. Coolant Temp Sensor
2. Oxygen Sensors
3. MAF sensor
4. I forgot the last one....dammit! I'll come back and edit this post when I recall. you can search my posts as well.
I'd begin with the cheapest and easiest item, the coolant temp sensor.
then, I would replace all four oxygen sensors, they're probably well overdue if they're originals.
the MAF sensor is typically the least likely, and most costly to replace.
i wanna say the fourth one is the TPS. Throttle Potentiometer Sensor. That's another costly, but more likely problem. for your problem, there's a way to test the TPS by checking the voltage reading at idle from two of the three wires. I believe you want to see a 0.6v Reading.
#3
05-05-2017, 10:47 AM
1. Clean the throttle body. It is probably sticky with old oil residue. That's the most common issue.
The rest of my recommendations are gonna have to do with the interesting point of your problem occurring with a warm engine. That means something is wrong with the closed loop operation of the engine.
the 4 biggest contributors to the fueling of your engine in closed loop is:
1. Coolant Temp Sensor
2. Oxygen Sensors
3. MAF sensor
4. I forgot the last one....dammit! I'll come back and edit this post when I recall. you can search my posts as well.
I'd begin with the cheapest and easiest item, the coolant temp sensor.
then, I would replace all four oxygen sensors, they're probably well overdue if they're originals.
the MAF sensor is typically the least likely, and most costly to replace.
i wanna say the fourth one is the TPS. Throttle Potentiometer Sensor. That's another costly, but more likely problem. for your problem, there's a way to test the TPS by checking the voltage reading at idle from two of the three wires. I believe you want to see a 0.6v Reading.
The rest of my recommendations are gonna have to do with the interesting point of your problem occurring with a warm engine. That means something is wrong with the closed loop operation of the engine.
the 4 biggest contributors to the fueling of your engine in closed loop is:
1. Coolant Temp Sensor
2. Oxygen Sensors
3. MAF sensor
4. I forgot the last one....dammit! I'll come back and edit this post when I recall. you can search my posts as well.
I'd begin with the cheapest and easiest item, the coolant temp sensor.
then, I would replace all four oxygen sensors, they're probably well overdue if they're originals.
the MAF sensor is typically the least likely, and most costly to replace.
i wanna say the fourth one is the TPS. Throttle Potentiometer Sensor. That's another costly, but more likely problem. for your problem, there's a way to test the TPS by checking the voltage reading at idle from two of the three wires. I believe you want to see a 0.6v Reading.
I've also been told that a low level of transmission oil and/or a not so healthy battery can cause the engine to stall.
Any comment please.
Thanks
#4
05-05-2017, 01:28 PM
Veteran Member
I'm sure there's a way that it could...
1. Transmission fluid. I'm assuming you've checked the level. Make sure it's a pretty cherry red and you can cross this one off your list.
2. Battery? Do your power locks work? The power locks are the first thing that begins to quit on you when the battery is on it's last legs. Is the car starting? Again, you'll have trouble starting the car if the battery was so weak as to affect the running of the engine.
The fact that you say you are experiencing problems when the car is warm, as opposed to cold indicates to me that something is wrong when the car goes off of its pre-programmed setting to operate the engine in closed loop, which now uses various sensors to determine fuelling. The battery and transmission fluid would cause you problems whether the car was warm or cold.
If you had something that could read the sensors, then it would be easier to figure out. I use a program specifically made for Apple products (there aren't many options) called Yhasi Movi. It would be able to tell you a lot.
It would tell you what the coolant sensor thinks the temperature of the coolant is.
It would show you the oxygen sensor readings.
It would even show the TPS position and the MAF readings.
While not perfect, it does help diagnose by either ruling things out, or highlight peculiarities. It also pulls and clears standard "P" codes.
1. Transmission fluid. I'm assuming you've checked the level. Make sure it's a pretty cherry red and you can cross this one off your list.
2. Battery? Do your power locks work? The power locks are the first thing that begins to quit on you when the battery is on it's last legs. Is the car starting? Again, you'll have trouble starting the car if the battery was so weak as to affect the running of the engine.
The fact that you say you are experiencing problems when the car is warm, as opposed to cold indicates to me that something is wrong when the car goes off of its pre-programmed setting to operate the engine in closed loop, which now uses various sensors to determine fuelling. The battery and transmission fluid would cause you problems whether the car was warm or cold.
If you had something that could read the sensors, then it would be easier to figure out. I use a program specifically made for Apple products (there aren't many options) called Yhasi Movi. It would be able to tell you a lot.
It would tell you what the coolant sensor thinks the temperature of the coolant is.
It would show you the oxygen sensor readings.
It would even show the TPS position and the MAF readings.
While not perfect, it does help diagnose by either ruling things out, or highlight peculiarities. It also pulls and clears standard "P" codes.
#5
05-06-2017, 09:37 AM
I'm sure there's a way that it could...
1. Transmission fluid. I'm assuming you've checked the level. Make sure it's a pretty cherry red and you can cross this one off your list.
2. Battery? Do your power locks work? The power locks are the first thing that begins to quit on you when the battery is on it's last legs. Is the car starting? Again, you'll have trouble starting the car if the battery was so weak as to affect the running of the engine.
The fact that you say you are experiencing problems when the car is warm, as opposed to cold indicates to me that something is wrong when the car goes off of its pre-programmed setting to operate the engine in closed loop, which now uses various sensors to determine fuelling. The battery and transmission fluid would cause you problems whether the car was warm or cold.
If you had something that could read the sensors, then it would be easier to figure out. I use a program specifically made for Apple products (there aren't many options) called Yhasi Movi. It would be able to tell you a lot.
It would tell you what the coolant sensor thinks the temperature of the coolant is.
It would show you the oxygen sensor readings.
It would even show the TPS position and the MAF readings.
While not perfect, it does help diagnose by either ruling things out, or highlight peculiarities. It also pulls and clears standard "P" codes.
1. Transmission fluid. I'm assuming you've checked the level. Make sure it's a pretty cherry red and you can cross this one off your list.
2. Battery? Do your power locks work? The power locks are the first thing that begins to quit on you when the battery is on it's last legs. Is the car starting? Again, you'll have trouble starting the car if the battery was so weak as to affect the running of the engine.
The fact that you say you are experiencing problems when the car is warm, as opposed to cold indicates to me that something is wrong when the car goes off of its pre-programmed setting to operate the engine in closed loop, which now uses various sensors to determine fuelling. The battery and transmission fluid would cause you problems whether the car was warm or cold.
If you had something that could read the sensors, then it would be easier to figure out. I use a program specifically made for Apple products (there aren't many options) called Yhasi Movi. It would be able to tell you a lot.
It would tell you what the coolant sensor thinks the temperature of the coolant is.
It would show you the oxygen sensor readings.
It would even show the TPS position and the MAF readings.
While not perfect, it does help diagnose by either ruling things out, or highlight peculiarities. It also pulls and clears standard "P" codes.