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.

 

I forgot to describe my car-- 2002 Jaguar Super 8 102k miles.

Ok, I've driven it for a half hour and the engine light is still on and it still hesitates but not as badly. The RP comes now and again and I haven't seen it recently.

 

Curtiss:
What car do you have?

 

Now do a "hard reset" Just disconnect a battery lead for a few seconds then reconnect it.
Also, I am a little confused. Does your MAF NOT look like the drawing. I think the AJ27 engine (which you have) might be a little different than the AJ26 diagram and like the one I looked at, but I did not remember any mounting difference. I will look at my AJ27 tomorrow.

Did you look carefully at the part load and full load breather tubes, the small one that connects to the left side valve cover, and the large one that connects to the right side? You do have an oil dip stick properly in position and a tight fitting oil fill cap? There is a round gasket between the air plenum and the Throttle body. Check it for leaks.

Essentially, if your MAFR is ok, then it is most likely that you are getting air into the engine intake after the MAF. If that is not it, then you need to go looking for low fuel pressure under load, which is another possibility. If you can get hold of a fuel pressure test guage, hook it up and tape it to the ouside of the windshield and make sure the pressure stays about 40 psig while accelerating.

 

I just installed my own intake and it cured my nagging RP and check engine light issues

 

No it does not look like that at all. It is very sparse and more rectagular. When you look inside there is just a drop down piece that looks like a teardrop. It looks like this picture: Remember the original owner switched to a K/N high performance oiled air filter. This filter box has a small hole at the bottom towards the front of the car. It is not a break or crack it was def. designed that way. Perhaps there was once a rubber plug in it for drainage? Throughout these discussions I am hearing about looking for cracks and here is a hole. The entire breather tube looks pretty new and clean, As does the hose to the valve cover. I will try the hard reset. How do I know if the MAF needs to be replaced?




2002 Super 8 102,000 miles

 

At times you may not see the leak and must resort to other means to find it. The right way to find the leaks is to use a smoke process but if that is not available you can use soapy water or throttle body cleaner. See the attached document and see if it helps.

Link http://www.jagrepair.com/images/Auto...otos/P0171.pdf

I would suggest putting the car back together and see if you can pinpoint the problem using the process in the attached document.

 

My whole damn intake was cracked and leaking... not just the seals. I didn't notice until i took it totally off, installed a new self-made one and ran the car... no Check Engine Light, no Restricted Performance, and increase in MPG and response... This issue plagued me for YEARS

 

I had my Intake manifold off because of leaks yesterday I replaced all the seals and inspected for cracks but did not see any. However, I think I still have a leak and I think it is a crack in the intake manifold. I hope to do a smoke test to verify my findings. On aircraft structures you used a die to find stress cracks I wish I had that option. All this with no codes.

 

As I understand your description of the hole, that is fine. You are looking for leaks after the MAF.
You are getting lots of good description of how to find plenum leaks and that is the most likely cause, BUT, it sure sounds like you may have the wrong MAF. I cannot see your picture. Could you try that again? Also, the specific problem of trouble during acceleration makes me think you might have a fuel pressure problem, although that is less likely than an air leak.

 

I did have a leaky intake manifold. Just throwing that out there, because I went through a lot to determine the problem after replacing intake seals. Apparently it was due to an overheating experience (I let the wife drive the car - long story). I did a crude smoke test and finally determined the manifold was leaking. I got a used one off of ebay and all is well now. I was getting the codes and I checked my fuel trims and they were very high and the ECU was dumping fuel to compensate. Probably not very common, but not something I would have guessed right off.

 

Curtis, the teardrop you are seeing on your MAF is just the temperature sensor. The actual airflow sensor is down inside the black plastic tube that sits beside the teardrop. To clean it you will need to remove the sensor from the section of duct it's built into. There's a rectangular box on the side of the duct which the harness plugs into. This is held to the duct with 2 screws. Undo these and pull the sensor out. This can be done with all the ducting in the car.

Once it's out, if you look down the tube beside the teardrop you'll see a circuit board and a couple of wires. Clean these wires thoroughly with MAF cleaner: visually clean isn't necessarily enough, they can get gunked up with a clear looking oil coating. Be careful not to touch them with the spray can tube, they're fragile.

 

Yeah, I understand the disconnect now. The MAF from the later AJ27 engine is "dropped into" a hole on the venturi and can be removed by removing the two screws for better cleaning. No so on the AJ26, SC that I wa slooking at.

 

Curtiss... I'm in tampa... I can swing down and look at it real quick if you want

 

What is a TB clean??

I just replaced my o2 upstream sensors and now the car posts the ASC and TRAC not available messages. Could I have upset anything when working in the area of the sensors under the bonnet/hood? I replaced the sensors from above and all seemed to go well enough. Now this has taken me by surprise!

 

Missing like mad, RP and CE, and no power. Broke down and bought a U480 Scanner (New) for less than $20 delivered to the door. Most likely cause seemed to be a coil pack at B2 (#4), then a coil pack on #6. Showing 99K and Random PO300 Causes could be related to low fuel pressure or contamination. Got a Fram G3727 Filter from my local Fleet Farm for less than $10. Will try that first.

 

We go through all of this and only wonder what would our world be like if Toyota had bought Jaguar.

 

Excalibur,
I sense your frustration, BUT, if Toyota had bought them maybe we would have run of the mill styling, lousy seats, and a damned Toyota badge on the car!

Now that you have a scanner, one of the tools you need to work on most any car, go ahead and read the codes and follow them to the correct diagnostic for the problem, then fix it. You might also want to invest in a fuel pressure test guage with enough hose that you can rig it to tape the guage on the ouside of the windscreen in order to test under acceleration.
Good luck!

 

Well, I for one would have been thrilled if Toyota had bought Jaguar instead of Ford/BMW. Most of the common faults (all the ones I am suffering) are due to poor quality Ford parts. BMW nikasil engines would not have ben an isse with Toyota.

We use a 2001 Alfa Romeo and a 2001 Lexus RX300 for work and have owned both cars since nearly new. Neither have ever missed a beat. the Lexus is far from pampered and has done about the same mileage as the Jaguar yet it is a far superior car in almost every department. It has NEVER broken down nor ever suffered even the tiniest electrical glitch. By contrast the Jag is tempramental and utterly fragile.

You can never fall in love with a Japanese car, they are a bit soulless...but if ONLY Toyota had detailed my Jaguar I would never have to worry and never have to lift the bonnet. And the electrics would ahve been sensible instead of an eccentric nightmare.

 

I for one think Ford did Jaguar a sterling service by making them a world wide brand, pity they didn't hang onto it long enough for it to pay off - TATA are now living the dream, Land Rover topping sales, XF best car 2013 and the new F type is just the dogs.

Most issues are down to neglect and the price of fixing these cars. Knowledge is a wonderful thing when dealing with them, they're simple beasts and many of the faults reported over and over again on here are usually simple fixes. A dud battery, a dodgy earth etc can create all sorts of messages that have no bearing on the issue.

If you find a Jaguar troublesome, run something Japanese and sleep easy.

I love a challenge, always have and old Jaguars are that and so much more.