Restrictive Performance Help!
#22
#23
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Without any codes you are shooting in the dark.
But, for what it is worth, here is where I would start.
Check all the ducting from the air box to the throttle body carefully for possible air leaking in. Pull the air filter and check the bottom of the air box for cracks.
Check that coils are not getting wet. (miss fire code?)
Clean the map sensor WITH MAP SENSOR spray.
Clean the Throttle Body. Don't get ANY of the cleaner on the MAP sensor.
Wiggle or re-seat all connectors to emission related sensors. (MAP, TPS, Temp, coils etc.)
The last time I had RP appear was 3-4 weeks ago (a real sucky feeling). I remedied the problem by simply re-seating the large duct hose exiting the air box's snout and clearing the too rich code. The top of the hose was slightly away from its seat by only 3/16" or so. Advice: When you tighten the hose make sure your clamp is parallel to and near the end of the tube where it is collapsible.
Good luck,
Brent in big D
But, for what it is worth, here is where I would start.
![Icon Rain](https://www.jaguarforums.com/forum/images/smilies/icon_rain.gif)
Check all the ducting from the air box to the throttle body carefully for possible air leaking in. Pull the air filter and check the bottom of the air box for cracks.
Check that coils are not getting wet. (miss fire code?)
Clean the map sensor WITH MAP SENSOR spray.
Clean the Throttle Body. Don't get ANY of the cleaner on the MAP sensor.
Wiggle or re-seat all connectors to emission related sensors. (MAP, TPS, Temp, coils etc.)
The last time I had RP appear was 3-4 weeks ago (a real sucky feeling). I remedied the problem by simply re-seating the large duct hose exiting the air box's snout and clearing the too rich code. The top of the hose was slightly away from its seat by only 3/16" or so. Advice: When you tighten the hose make sure your clamp is parallel to and near the end of the tube where it is collapsible.
Good luck,
Brent in big D
#24
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Right now I have the engine light on and the ABS light on at 101000 miles. The engine is running very smooth..........almost can't tell its running at idle. Awhile back I had the restricted performance light come on when driving fast on the highway 80-90 mph. That light has not come on in awhile but I can't accelerate normally at any speed. If I slowly push down the accelerator I can usually get going smoothly and once at speed 20 or so it runs fine unless I mash the accelerator. Any mashing gets a huge lag to where I have to take my foot off the pedal and go at it slowly. So, at high speeds if I want to pass someone I have to increase speed gradually which still works fine but I need to figure out what is wrong. I had a guy look at it and we cleaned and reoiled the air filter, changed the oil and that's about it. He did some diagnostics and said it could be anything. After reading these links I am going to go to auto zone and have them run a diagnostic to get some codes and I am also going to look through all the hoses and connections to make sure there are no cracks or bad connections. It is hard to see much with the supercharger sitting on top of everything though and I am not a mechanic. I also just found out that my drivers side boot on the steering rack is leaking fluid. I was told it had to be changed out and it would be $2k with the rack costing $1400 of that. $300 labor and $90 tranny fluid kit, flush install etc. and then alignment. I went online to shop the rack and found them to be about $400 reman'd (the 1400 one is also a reman). Why such a difference and how hard is it to install the rack? It seems the work is in the fluid install.
curtiss
2002 Super 8 101,000
curtiss
2002 Super 8 101,000
#25
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Curtiss:
I just changed my steering rack and the rebuilt unit from PartsGeek was about $325. After an alignment, I will have $400. in the job, with about 2hrs of my time.
As to the inability to rev, you need to get the codes. BTW, you mention re-oiling the air filter. Look into the archives. Plenty of folks have reported problems after changing to a KN filter. I recommend you put the stock filter back on it.
The codes generally tell the story. "Running some diagnostics" and reporting it could be anything is pretty weak. Get the codes and report back.
I just changed my steering rack and the rebuilt unit from PartsGeek was about $325. After an alignment, I will have $400. in the job, with about 2hrs of my time.
As to the inability to rev, you need to get the codes. BTW, you mention re-oiling the air filter. Look into the archives. Plenty of folks have reported problems after changing to a KN filter. I recommend you put the stock filter back on it.
The codes generally tell the story. "Running some diagnostics" and reporting it could be anything is pretty weak. Get the codes and report back.
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Curtiss (05-12-2013)
#26
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I realized I didn't ask a question in regards to the accel. Lag. Does anyone have any ideas on why this occurs when it seems to be running so well? The one mechanic that looked at it said it's a crapshoot and just to start trying different things. That can get expensive. The points that I think are important are as follows: engine is very smooth at all speeds except at acceleration, temp is always good, oil pressure is always good, I use high octane gas, no knocking coming from engine, smooth acceleration if I don't punch it. Biggest problem is pulling out into traffic. Normally, I'd be confident but if i push too hard it will buck back so I have to take my foot off of the accelerator and start over. It does not stall or act like it will stall, just seems like there was no gas. Restricted performance light had come on in past. ABS light is on. Engine light is on. Any help would be appreciated.
Curtis in Sarasota
2002 Jaguar Super 8 101,000
Curtis in Sarasota
2002 Jaguar Super 8 101,000
#27
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Ross,
Thanks for your reply. How hard is it to get the lines clear and what tools did you have to have to do so for the rack?
In regards to the air filter, I bought it with the high performance installed. Should I remove it for a test drive and see if there is a difference?
thanks again and I'll get codes this week and post an update. It's such a beautiful car but it takes the fun out of it when you can't spin the tires
Thanks for your reply. How hard is it to get the lines clear and what tools did you have to have to do so for the rack?
In regards to the air filter, I bought it with the high performance installed. Should I remove it for a test drive and see if there is a difference?
thanks again and I'll get codes this week and post an update. It's such a beautiful car but it takes the fun out of it when you can't spin the tires
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#28
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The X-308 has the SIMPLEST rack fluid lines I have ever seen. One bolt with a pull down plate! Be sure to set and tie the steering wheel to center before you remove the pinion coupling. Remember there is a "clockspring" in the column to transfer the steering wheel switch circuits to the column. There are four bolts that hold the rack to the car. A 13 mm as I recall. A socket wrench with a short extension is required. You will need a 22mm and a 23 mm open end wrench to disconnect the tie rods. Release the outer boot keeper tie and push the boots back on the tie rods then installing the new rack. Get a catchpan under there before you pull the lines or you will be working in adverse conditions!
Do you have the original air filter case? I sure as heck would not run it without an air cleaner.
OH- GET THE DURNED CODES READ!
Do you have the original air filter case? I sure as heck would not run it without an air cleaner.
OH- GET THE DURNED CODES READ!
#30
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Curtiss:
Your codes indicate both banks are running lean. While there ar multiple possibilities, the most likely cause is an air leak betweeen the Mass airflow sensor and the Throttle Body. Check the entire intake plenum carefully for cracks, especially near the two resonators. Check the Full Load breather- the tube that runs from the plenum immediately behind the MAF to the top of the right valve cover. Check the seal at the throttle body. Then check the rubber doughnuts between the supercharger and the two intercoolers.
If you are sure the above look good, the next stop is to check the fuel pressure, both at idle and when you stomp it. That is done by rigging a test pressure guage with a longer hose so you can tape it to the OUTSIDE of the windshield and close the hood while watching the pressure. It should vary with manifold pressure, but be about 40 psi.
As Brent said, it could also be a dirty MAF. Especially likely if it has become coated in oil from the aftermarket filter.
Having a scanner that can read the STFT, which is controlled by the O2 sensors, would help get to the problem quickly, if you can borrow such a sensor.
While there are a number of things that can cause lean running, in most cases the root cause can be found fairly quickly with the right tools. I sure wouldn't characterize the problem as "could be anything". It just requires some logical troubleshooting.
Report back what you find!
Your codes indicate both banks are running lean. While there ar multiple possibilities, the most likely cause is an air leak betweeen the Mass airflow sensor and the Throttle Body. Check the entire intake plenum carefully for cracks, especially near the two resonators. Check the Full Load breather- the tube that runs from the plenum immediately behind the MAF to the top of the right valve cover. Check the seal at the throttle body. Then check the rubber doughnuts between the supercharger and the two intercoolers.
If you are sure the above look good, the next stop is to check the fuel pressure, both at idle and when you stomp it. That is done by rigging a test pressure guage with a longer hose so you can tape it to the OUTSIDE of the windshield and close the hood while watching the pressure. It should vary with manifold pressure, but be about 40 psi.
As Brent said, it could also be a dirty MAF. Especially likely if it has become coated in oil from the aftermarket filter.
Having a scanner that can read the STFT, which is controlled by the O2 sensors, would help get to the problem quickly, if you can borrow such a sensor.
While there are a number of things that can cause lean running, in most cases the root cause can be found fairly quickly with the right tools. I sure wouldn't characterize the problem as "could be anything". It just requires some logical troubleshooting.
Report back what you find!
Last edited by sparkenzap; 05-13-2013 at 04:10 PM.
#31
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I had an intermittent Restricted Performace problem that would come and go at will on my 2000 XJR. Started less often then increased frequency as time went on but no rhyme or reason as to driving style that seemed to cause it. Came with a check engine lights, code read P0175 Bank 2 Rich, never had P0172. I cleaned the MAF and throttle body with the corresponding cleaners and it went away for about 2-3 months.
Then it returned, with more frequency this time with both P0175 and P0172 (every so often it would only be the 175 code but I think it had to do with the quickness that I cleared the codes not allowing the 172 to show up). At this point I recleaned the MAF, installed a new MANN air filter, and also followed the How-To posted on a potentional connection issue between the connector and MAF sensor (required bending of the tabs on the MAF itself). This again helped for about a month maybe 2, and it returned with a vengence.
This time it was much more frequent and finally the check engine light gave me P0175 and P0172 PLUS P0505 (Airflow valve issue). I had delayed the inevitable long enough. I needed a new MAF, bought one new from the local World Pack parts distributor (brand new OEM Jaguar assembly) installed it and been trouble free. (be sure to disconnect the battery and touch the terminals prior to driving again or it will run like crap).
Oh and also the car runs like a beast now. Much faster and more responsive so I definitely recommend just changing it and not dealing with it for 6 or so months. You may lose some races you would otherwise win with it repaired. Not to mention you have someone come up and challenge you and you can do nothing about it because you can only rev your motor to 3000 RPM. HAHA.
RP Intermittent Issue
Check Engine lights corressponding to RP: P0175 (bank #2 rich), P0172 (bank #1 rich) and finally P0505 (airflow meter out of range)
Repair: Replace Mass Air Flow Meter (can try cleaning first but it did not solve it on mine required replacement)
Then it returned, with more frequency this time with both P0175 and P0172 (every so often it would only be the 175 code but I think it had to do with the quickness that I cleared the codes not allowing the 172 to show up). At this point I recleaned the MAF, installed a new MANN air filter, and also followed the How-To posted on a potentional connection issue between the connector and MAF sensor (required bending of the tabs on the MAF itself). This again helped for about a month maybe 2, and it returned with a vengence.
This time it was much more frequent and finally the check engine light gave me P0175 and P0172 PLUS P0505 (Airflow valve issue). I had delayed the inevitable long enough. I needed a new MAF, bought one new from the local World Pack parts distributor (brand new OEM Jaguar assembly) installed it and been trouble free. (be sure to disconnect the battery and touch the terminals prior to driving again or it will run like crap).
Oh and also the car runs like a beast now. Much faster and more responsive so I definitely recommend just changing it and not dealing with it for 6 or so months. You may lose some races you would otherwise win with it repaired. Not to mention you have someone come up and challenge you and you can do nothing about it because you can only rev your motor to 3000 RPM. HAHA.
RP Intermittent Issue
Check Engine lights corressponding to RP: P0175 (bank #2 rich), P0172 (bank #1 rich) and finally P0505 (airflow meter out of range)
Repair: Replace Mass Air Flow Meter (can try cleaning first but it did not solve it on mine required replacement)
#33
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#35
#36
#37
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How do you clean the MAF and is this the plug in at the air filter? I am not finding any cracks but when I went through the air filter system I pulled out the filter and unplugged what I think the MAF is and kind of pushed everything in a little tighter and the engine light went out for a few days. I want to try to clean the MAF first before I change out the high performance filter and box to an original filter per your suggestion. The box does not look square to me so when I close it the filter might not seal the way it should. The box closes super tight though. I am not sure what the MAF looks like or how to clean it.
#38
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Look at Item 1 in the picture. Specifically, you are cleaning a little wire down in the plastic piece that protrudes into the center of the airflow, behind the hole with the X shape there in the center of the airflow venturi. Use a can of MAF spray available from the auto parts, read the instructions and DO NOT FORCE THE CLEANER TUBE INTO THE HOLE. The sense element is very fragile. JUst spray plenty of cleaner in there, from both directions. I do not recall exactly how the X-308 MAF element looks, but what you are cleaning are two thin lire looking things thet cross the airflow. You may or may not actually see them looking into that hole. Don't let the cleaner tube touch those elements, just wash the crud off with the spray
#39
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I might also add to Ross's comments ;o]
While you have the MAF in your hot hairy mit....have a look down inside the induction side...to right of centre what looks like a little plastic tit (steady boys)...this is the mean air temp. sensor and should also be cleaned by spraying.
When finished just give it a good shake and let it air dry....NEVER use compressed air on a MAF that's a sure of buggering it.
My car has covered 200,000klm and still on the original ;o]
Make sure on re installation that you replace the worm drive clamps in the right place....up against the plastic stoppings and make sure the trunking is well pushed onto the MAF seal before tightening up the clamp.
Quite often erratic running is atributable to a 'rogue' air leak at this point 'upstream' of the MAF which upsets the paramerters.
Also check for any cracks or fractures in the 'ainti resonance' attached at the rear of the air trunking.
Also check condition and integrity of 'full load breather' where it both attaches tot he trunking and 'A' bank cam cover.
All these places have the potential to create 'rogue air' leaks.
While you have the MAF in your hot hairy mit....have a look down inside the induction side...to right of centre what looks like a little plastic tit (steady boys)...this is the mean air temp. sensor and should also be cleaned by spraying.
When finished just give it a good shake and let it air dry....NEVER use compressed air on a MAF that's a sure of buggering it.
My car has covered 200,000klm and still on the original ;o]
Make sure on re installation that you replace the worm drive clamps in the right place....up against the plastic stoppings and make sure the trunking is well pushed onto the MAF seal before tightening up the clamp.
Quite often erratic running is atributable to a 'rogue' air leak at this point 'upstream' of the MAF which upsets the paramerters.
Also check for any cracks or fractures in the 'ainti resonance' attached at the rear of the air trunking.
Also check condition and integrity of 'full load breather' where it both attaches tot he trunking and 'A' bank cam cover.
All these places have the potential to create 'rogue air' leaks.
Last edited by xjay8; 06-12-2013 at 08:14 AM.
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Curtiss (06-12-2013),
sparkenzap (06-12-2013)
#40
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thank you for your help with this. I removed the entire body from the filter to the intake port. The MAF is very simplistic on this car. It was actually attached and seemed part of the top of the filter housing. There were two little wires which were part of what looked like a tear drop and that's it. I sprayed the wires directly several times and they did not appear to have any gunk on them. I made sure everything was seated back tightly and properly and I found no cracks anywhere. I did find a small hole at the bottom of the filter housing that looks like it might be a drainage port. It was definitely meant to be there but perhaps there should be a plug? It's very small. Like the size of a small panel nail. I started the car up and the engine light stayed on and upon acceleration it did the same hesitation. I have not driven it yet but If anything changes after I do, I'll let you know.