Thread: My P38 is not behaving it self

Hi Pete,
yes that is the first time I have had bad fuel for a long time. The last time the fuel was full of dirt (fine rust) and it went into my boat. We got about 35 mile out to sea and the whole fuel system was blocked. I had to keep dismantling and cleaning the fuel system to try to get home. It took hours, but we made it home. We went down the river again this morning and the hesitation is only just noticeable when you start off cold, then it is gone. So I think will get better when I use up this fuel which is 50/50 new and old.
Regards,
Alan

Hi folks, well things have progressed, sort of. Just before Christmas I ordered a pair of O2 sensors, as some times it just would not run right. And they turned up on Christmas eve. When I opened the box, wrong ones. So today was my first day back at work for 13 months. After a couple of hours in the office I had enough, so I went to the workshop and put the scan tool on my P38 and went for a drive, and it started to play up, and I could see one O2 sensor was working correctly and the other one was doing nothing. And it played up on the way home as well, and I still had the scan tool on it and I could see it on the graph again. I have another one, second hand, but I think it is OK. So tomorrow I will change them over and see if that fixes the intermittent problem. On another note I went to see the doctor today and it looks like I have two more skin cancers on my right hand that I have to get cut out. I guess welding without gloves is not good for you. So I will see what tomorrow brings.
Regards,
Alan Temperley

Ah, bugger about the skin cancers Alan, geez you are having a tough run there, hope they get this sorted for you and that's the end of it.

Did you get genuine 02 sensors, or after market?
I got after market O2 sensors for mine and had all sorts of problems with them.
The plugs were covered in black soot, it was even coming out of the exhaust!
Then I got genuine Bosch sensors, (mine is a 2001 Thor 4.6) and the problem was solved straight away, I just had to reset the long term fuel trims and all was good instantly.

Hi Peter,
yes the skin cancer is giving mea hard time. But at least there is only two. Not sixteen like last time. I ordered a set of Bosch ones, but they were not correct. they were listed for a P38 but they were for a L322. So I sent them back. I have now ordered a set from my local Land Rover specialist. So while I am waiting for them to arrive I am playing around with the second hand ones I have. If I can get it to run OK on these, I can put them in the back of the car as a set of usable spares. The spares box is overflowing.
Regards,
Alan Temperley

(skin) cancer sucks good luck with that mate!

Anyway, regarding the O2 sensors. The last time I replaced mine a got a set of cheapies from... I believe spain? They have given me some headache. Somehow OEM stuff is usually better, go figure

Cheers,
-P

Hi Prelude,
yes pretty much over the operations and pain etc. I have OEM ones ordered, might be here tomorrow, so hopefully that will fix it. But I am not ruling out a wiring fault. That was the problem with the knock sensors. I replaced the knock sensors and the problem was still there so I opened the wiring harness and the insulation on the wires had turned to dust, and all the wires were touching together, so I replaced the wires and earth shield and all was good.
Regards,
Alan Temperley

Alan, do you have a way of resetting the long term fuel trims?
I have a faultmate extreme which does the job, after I fitted the new 02 sensors, resetting the long term fuel trims had it instantly running perfectly.
Once you fit the genuine 02 sensors, you will need to do that.
Hopefully that will have it sorted for you.

Hi Peter,
yes one of the scan tools that I have access to will reset the fuel trims, when I get that far. I finally got my new O2 sensors and fitted them on Friday. We still could not get it to run right and the scan tool said that the right side O2 sensor was shorted to earth. But the left one was working, producing a good signal. Also the scan tool said the air flow meter was not working, constantly showing idle air flow. So I replaced this and now at least that is working. So I gave up and went home, Thinking that the problem must be in the wiring harness. So this morning I dismantled the car enough to remove the wiring down the right side of the motor and cut it open all the way up to the computer, and I removed the earth shield. and tested for shorts to earth and it was still shorted. So I checked the pins on the computer and I found the left and right sensor wires are joined together. (red black wire) So then I removed the wiring to the left O2 sensor and opened up the harness. And bugger me Bob the butcher had been working in there. So I cut out all his crap wiring and tested for shorts to earth and all was good. By that time it was getting dark and the mozzies were starting to bite so I packed up and I will put it all back together tomorrow.
Regards,
Alan