Ok, I guess I will throw in my 2 cents! I am definatly with the other guys, It is a sensor problem. Some times just unplugging things can give you a false result. I had a bad idle problem and poor gas milage after I cleaned my stepper motor and pcv valve. I unplugged my VSS, %85 of my symptoms went away. Ok, get new one, installed, same problem, but I sure solved all of my misfires!! So back to square one, bad idle, and gas milage. I called my local independant rover shop, I was told my computer needs to be purged. This cost me $75.00 and was done in a matter of min. This diagnostic read all of my sensors, all was working properly. I HIGHLY SUGGEST GETTING YOUR ROVER CONNECTED TO THIS DIAGNOSTIC. This will tell you everything your truck is doing!
Good luck!!!
Good luck!!!
C
Craigness
Guest
Ricardo to the botch!
I had the truck brought over to "Ricardo" at Foriegn Car Center in LIC Queens. Man that guy is a piece of work. It should be agaist the law for this man to even lease an autologic.
I have no idea what he did but he told me (Indirectly) that one cat is hollowed out and that my idle was off. Well the truck no longer has the terrible misfire but now only has about 60% of its power and idles like crap. I cant even call him to ask what he did because I burnt that bridge when I cought him cheating me out of over $1200 for a repair.
Be careful with this guy. GET EVERYTHING IN WRITING or he will sick his forked tounged daughter on you. I hope she does not inheret the business.
Anyway, I have no idea what the bastard did but now i'm totaly screwed. Truck still shakes, is loud and I have to wind out the rpm's to 5G before I can shift. In fact, i'm sooo pissed off that i'm starting a thread on him.
I had the truck brought over to "Ricardo" at Foriegn Car Center in LIC Queens. Man that guy is a piece of work. It should be agaist the law for this man to even lease an autologic.
I have no idea what he did but he told me (Indirectly) that one cat is hollowed out and that my idle was off. Well the truck no longer has the terrible misfire but now only has about 60% of its power and idles like crap. I cant even call him to ask what he did because I burnt that bridge when I cought him cheating me out of over $1200 for a repair.
Be careful with this guy. GET EVERYTHING IN WRITING or he will sick his forked tounged daughter on you. I hope she does not inheret the business.
Anyway, I have no idea what the bastard did but now i'm totaly screwed. Truck still shakes, is loud and I have to wind out the rpm's to 5G before I can shift. In fact, i'm sooo pissed off that i'm starting a thread on him.
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C
Craigness
Guest
it's doing it AGAIN!
OK, after bringing the truck to Ricardo for a diag, I got the truck back and the problem was somwhat fixed. Still a slightly rough idle but no more misfireing on throttle. This was fine for two weeks and on Friday it all started again.
WTF is going on with my truck!!!!! Do I need another shot of whatever Ricardo did? He would not tell me what he did to stop this. I mean, when I got it back it only had about 70% of it's total power, but no more misfire. Could he have detuned the ECU or something? I also see marks on the throttle body ajustment cap like he pryed it out to set the throttle mix set screw.
Could this be a leaking injector? It's coming from the drivers side and you can hear it in the pipe on that side. Also, it seems to "pop" free under full throttle. Definatly running rich as the car smells like rich combustion.
Car does not smoke. Starts fine. Runs ok (Not great but ok) for the first 10 minutes the stutters like mad.
I'm starting to think about the dealer..... HELP.
OK, after bringing the truck to Ricardo for a diag, I got the truck back and the problem was somwhat fixed. Still a slightly rough idle but no more misfireing on throttle. This was fine for two weeks and on Friday it all started again.
WTF is going on with my truck!!!!! Do I need another shot of whatever Ricardo did? He would not tell me what he did to stop this. I mean, when I got it back it only had about 70% of it's total power, but no more misfire. Could he have detuned the ECU or something? I also see marks on the throttle body ajustment cap like he pryed it out to set the throttle mix set screw.
Could this be a leaking injector? It's coming from the drivers side and you can hear it in the pipe on that side. Also, it seems to "pop" free under full throttle. Definatly running rich as the car smells like rich combustion.
Car does not smoke. Starts fine. Runs ok (Not great but ok) for the first 10 minutes the stutters like mad.
I'm starting to think about the dealer..... HELP.
O2'z
My truck did the same thing after I rebuilt the top end and put in new O2 sensors. Started right up, but backfired under load, hesitated a lot, idled shitty, but at factory setting - basically ran like doo doo.
I accidentally hooked the front O2 sensors up to the wrong connector when I installed the new O2'z.
So front right sensor was sending to front left parameter and viceversa.
Switched them back over and she runs like a dream.
Dan
My truck did the same thing after I rebuilt the top end and put in new O2 sensors. Started right up, but backfired under load, hesitated a lot, idled shitty, but at factory setting - basically ran like doo doo.
I accidentally hooked the front O2 sensors up to the wrong connector when I installed the new O2'z.
So front right sensor was sending to front left parameter and viceversa.
Switched them back over and she runs like a dream.
Dan
C
Craigness
Guest
Craig, I thought you had S&A Engine rebuilders do your valve job? Didnt they also port and polish?
C
Craigness
Guest
port & polish
Yes, they did a great job but that was NOT my problem.
I just gave AB a c-note for a VSS module and we will see what that does. I think it's another sensor down the drain and this will not fix my problem as the car runs like shit from the startup before it moves an inch.
Lots of remidies if you got the cash.....
Yes, they did a great job but that was NOT my problem.
I just gave AB a c-note for a VSS module and we will see what that does. I think it's another sensor down the drain and this will not fix my problem as the car runs like shit from the startup before it moves an inch.
Lots of remidies if you got the cash.....
ptschram
Well-known member
Find another Rovacom equipped shop, or maybe run it up to Robison and see what he says.
It might well be worth it.
PT
It might well be worth it.
PT
C
Craigness
Guest
Rovacom
I have been told that it's possible that the O2 sensors are mixed up. That the downstream left might be plugged into the upstream left or somthing to that effect. I was tying with unplugging them one at a time and see what code gets stored to identify the cables.
Also, there has been a modification to the drivers side cat. There is a welded plate on the rear bottom of it about 8 square inches in size or about the size of a playing card. It might be hollow? If you hollow out a cat, would it cause the computer to wig out wihtout setting off an O2 code? Woudl the hesitation and stumbling after warm up come from that?
I got the VSS sensor from AB yesterday but are thinking twice about installing it as one I do, I own it.
I have been told that it's possible that the O2 sensors are mixed up. That the downstream left might be plugged into the upstream left or somthing to that effect. I was tying with unplugging them one at a time and see what code gets stored to identify the cables.
Also, there has been a modification to the drivers side cat. There is a welded plate on the rear bottom of it about 8 square inches in size or about the size of a playing card. It might be hollow? If you hollow out a cat, would it cause the computer to wig out wihtout setting off an O2 code? Woudl the hesitation and stumbling after warm up come from that?
I got the VSS sensor from AB yesterday but are thinking twice about installing it as one I do, I own it.
ptschram
Well-known member
Craigness said:
The hollowed out cat would definitely give you a CEL as that's what it's for.
Why did you buy from AB? There are many better vendors with the same or better parts/prices and almost everybody has better customer service. Also, VSS failure supposedly will only cause odd-cylinder misfires.
PT
C
Craigness
Guest
VSS Failure
I am getting odd-cylinder misfires.
So, now I need to change the "Y" pipe and this thing.
Do I need to get my ECU flushed afterwards?
I am getting odd-cylinder misfires.
So, now I need to change the "Y" pipe and this thing.
Do I need to get my ECU flushed afterwards?
ptschram
Well-known member
Craigness said:
Not necessarily. Eventually, the ECU will learn the right way to behave, but it will require the magic number of start/stop, heat up, cool down cycles. It would be faster to reset the adaptive values, but not absolutely necessary.
It is really cool to take a truck that runs poorly, repair the stuff it needed and then reset the adaptives and watch it immediately come to life.
PT
C
Craigness
Guest
weird stuff
Well while driving home tonight the CEL started to blink at a red light when the truck was shaking and it smoothed out real nice while it was blinking. I know people have told me that when it blinks it's cutting back or somehting to even out the misfire.
Will someone PLEASE tell me why it really blinks and runs good when it does this?
Well while driving home tonight the CEL started to blink at a red light when the truck was shaking and it smoothed out real nice while it was blinking. I know people have told me that when it blinks it's cutting back or somehting to even out the misfire.
Will someone PLEASE tell me why it really blinks and runs good when it does this?
blinking means you are in real trouble...though the list of misfortune you have had makes me wonder.
I'd get AAA gold membership and see how close you can get to Robisons.......
I'd get AAA gold membership and see how close you can get to Robisons.......
C
Craigness
Guest
The development and adoption of legislation calling for more stringent automotive emission requirements, initiated by the California Air Resources Board (CARB ), is now part of the Federal Clean Air Act. This legislation is an extension and enhancement of previous requirements (OBD ) and is known as On-Board Diagnostics II (OBD II ). Federal law requires that by the 1996 model year, vehicles sold in the United States meet common standards for emission control and diagnostic capability. GEMS allows Land Rover products to meet these operating standards.
Monitoring Emissions Performance
The original OBD required that vehicles monitor operation of key components such as oxygen sensors, fuel delivery system, and the module controlling the system's powertrain. Failure of components in these systems is indicated by Malfunction Indicator Lamp (MIL ) illumination and generation of a Diagnostic Trouble Code (DTC ).
OBD II takes this monitoring a step further by not only checking the operation of emission components, but their performance. While the difference between monitoring operation and performance may sound small, the changes to ECM operating strategies required to accomplish this are enormous.
The ECM detects engine misfire by measuring the contribution each cylinder makes to engine performance. This is calculated from measurements of crankshaft acceleration for each cylinder provided by the crankshaft position sensor.
The acceleration for each cylinder is determined from the crankshaft rotation velocity. The GEMS performs a series of calculations to determine the acceleration rates of the individual cylinders. When a cylinder's acceleration falls outside of a predetermined range, the GEMS takes a closer look at the signal.
For example, operating conditions such as rough roads or high rpm/light load operation can provide misfire-like changes in crankshaft acceleration. Internal programming in the GEMS is designed to filter out these look-alike signals and focus on real misfire. The GEMS separates misfire into two classifications, and has a different response for each.
Type A Misfire:
This is a serious misfire situation where raw fuel entering the TWC can cause excessive catalyst temperatures. This could quickly cause permanent damage to the TWC. In this situation, the MIL lamp illuminates iminediately and flashes to attract the driver's attention. Continued operation at this point will damage the TWC.
Type B Misfire:
A second type of response occurs when the GEMS detects a low-level misfire. At lower levels, misfire will not significantly raise TWC temperature but will produce excessive vehicle emissions. In this situation, the GEMS records a DTC. The GEMS will illuminate the MIL if this failure is repeated during a second consecutive drive cycle where operating conditions (engine warm-up, rpm and load) are approximately the same. Should the misfire not reappear under these conditions on three consecutive trips, the MIL will turn OFF
Monitoring Emissions Performance
The original OBD required that vehicles monitor operation of key components such as oxygen sensors, fuel delivery system, and the module controlling the system's powertrain. Failure of components in these systems is indicated by Malfunction Indicator Lamp (MIL ) illumination and generation of a Diagnostic Trouble Code (DTC ).
OBD II takes this monitoring a step further by not only checking the operation of emission components, but their performance. While the difference between monitoring operation and performance may sound small, the changes to ECM operating strategies required to accomplish this are enormous.
The ECM detects engine misfire by measuring the contribution each cylinder makes to engine performance. This is calculated from measurements of crankshaft acceleration for each cylinder provided by the crankshaft position sensor.
The acceleration for each cylinder is determined from the crankshaft rotation velocity. The GEMS performs a series of calculations to determine the acceleration rates of the individual cylinders. When a cylinder's acceleration falls outside of a predetermined range, the GEMS takes a closer look at the signal.
For example, operating conditions such as rough roads or high rpm/light load operation can provide misfire-like changes in crankshaft acceleration. Internal programming in the GEMS is designed to filter out these look-alike signals and focus on real misfire. The GEMS separates misfire into two classifications, and has a different response for each.
Type A Misfire:
This is a serious misfire situation where raw fuel entering the TWC can cause excessive catalyst temperatures. This could quickly cause permanent damage to the TWC. In this situation, the MIL lamp illuminates iminediately and flashes to attract the driver's attention. Continued operation at this point will damage the TWC.
Type B Misfire:
A second type of response occurs when the GEMS detects a low-level misfire. At lower levels, misfire will not significantly raise TWC temperature but will produce excessive vehicle emissions. In this situation, the GEMS records a DTC. The GEMS will illuminate the MIL if this failure is repeated during a second consecutive drive cycle where operating conditions (engine warm-up, rpm and load) are approximately the same. Should the misfire not reappear under these conditions on three consecutive trips, the MIL will turn OFF
C
Craigness
Guest
But.....
This does not tell me why the engine runs great while its flashing. Also, the flashing stops after 30 seconds or so in most cases and returns to steady on.
In my opinion, the computer is returning to closed loop mode while it's flashing and then returns to the drive cycle again. But what do I know.
The only answer I need is would a lack of a left side catalyst cause the car to misfire and hesitate after warm up? Remeber, the car runs somwhat well on cold start. No misfires, no hesitation. Whatever is happening is starting after warm up.
This does not tell me why the engine runs great while its flashing. Also, the flashing stops after 30 seconds or so in most cases and returns to steady on.
In my opinion, the computer is returning to closed loop mode while it's flashing and then returns to the drive cycle again. But what do I know.
The only answer I need is would a lack of a left side catalyst cause the car to misfire and hesitate after warm up? Remeber, the car runs somwhat well on cold start. No misfires, no hesitation. Whatever is happening is starting after warm up.