The P0101 code will be set if the voltage from the MAF sensor (airflow part) is a certain amount higher or lower (think it was >50 gr/s) compared to the throttle position. This is only measured at a low speed at steady drive for a certain amount of time, hope this helps.

 

Many thanks Avos, could you just please explain to me the part ">50 gr/s" and what this means please?

 

">50 gr/s" means more then 50 grams of air per second. This is a translation from the ECU based on the 1voltage from received from the MAF sensor. That could be about 0.4 volts or so, I do not have the details unfortunately.

 

Still no result but I now have the report from the Jaguar dealer. It goes as follows.........

Customer states misfire codes on 4 cylinders. All coils and both spark control modules have been replaced. Checked for codes and retrieved P1367, P1368, P0354, P0351, P0356, P0357, P1223, U2012, U1095, and P1799. Tried a test ECU and car did not run any better. Found loose cable to front fuse box. Tested grounds and started to test ignition system, Fuel pressure good but losing ignition 4 new coils in car. Need more diagnostic time to get definitive answer on problems with car.
(charge $250.00)
Can anyone throw any more light on this for me please?

 

Now mechanic thinks there is an "injector pulse shutdown". The car starts and runs for approx 20 seconds then shuts down. It starts on the key again a few seconds later. Anyone got any answers for this as he still does not know wher to find the fault and it's driving me nuts!!!

 

Put a fuel pressure gauge on it as it is running and see if the pressure goes down before the engine dies.

 

Finally located the problem to ECU. Bought rebuilt unit from Auto & Truck Electronics for $389. Quick painless transaction and recommended.
The same I could not say for Collier Jaguar in Orlando (now Infinity Jaguar) who apparently told my mechanic they had swopped the ECU for their test unit and it was NOT the problem. Well it turns out they were lying then because it WAS the problem. My mechanic went looking for other answers in the loom etc and cost me another four weeks off the road and considerable extra hours of his time to pay for. This is the second time they have given me bad information, first was when the soft top would not go up or down properly, told me it would cost $3000 to fix and all it eventually needed was $20 of speciality oil. Do not go there people!

 

I think this problem was driving us all crazy. It was a long hard road that got you to the ECU and troubleshooting from afar is difficult. I would like to know what took you to the ECU or was this your last course of action?

 

Gus, what took us there was we had literally gone over everything even to the point of individually testing continuity of each 5volt wire. We were starting to check things again for the second time and I had said to mechanic that I had been mislead by the Jaguar dealer in the past and that I didn't trust them. It was as much as a last resort really to get the ECU rebuilt as there was nothing else left.
I spent the whole day yesterday lovingly polishing her inside and out to get rid of all the mechanics dirty marks off her (8 weeks in the garage) Mechanics go through the pretence of wearing gloves and putting in a paper mat on the floor etc, does nothing except put on a show of keeping the car clean. She is now pristine again.

 

Kudos to you!

 

When I read this I feel very bad. The initial problem of oil in the spark plug wells was the only problem. Oil in the wells does not cause the coils to fail. If new gaskets and spark plugs hand been insalled, and the codes shut off you would be on the road. That car has been fixed so much know I don't know what to do next. You need a good on-site advisor that has done this before.

 

I have noticed that each day a new opportunity arises on these cars. It is extremely difficult to troubleshoot over the internet and the reasons are many but most of all it is the interpretation of the information given. Along with that you receive information from many that are talented with supporting information that leads to believe you are on the right track.

I personally am thankful that the problem was found by Phil. He was dedicated and was not intimidated and best of all he did not give up. Keep in mind this topic took 31 posts and two mechanics and the one that found it was a tenacious as the owner. I will try to keep this information available for future reference but to say all related situations are caused by this ECU problem would be an untruth.

 

I had the same issue with my 2001 xk8...
turned out one of the 4 O2 sensors was faulty caused my mechaic believes by a coolant leak from heater hoses.
it was intermittant, and has since disapeared since i fixed the hoses, but does come back once in a while if I dont drive the car for a week or so. ( i just put it down to her being jealous when i go out with other cars, and having a tantrum! haha!)

 

Wow what a nightmare of a problem. So glad you got it fixed. These are the types of problems that keep you worrying about owning an XK. Luckily everything is working on mine at present. I want to buy the Nameless Performance Catalytic Converters for more power. However; I'm afraid as soon as I spend $700 on them, something expensive is going to fail...like the TB/TPS, ECU, CATS dampers, etc. etc.

BTW: I live in Central Fl, guess I won't be going to Jaguar of Orlando for any work. Phil the Brit did you take the car to All Jaguar in Longwood to do the troubleshooting and repairs?