Hello all, my name is Ryan and I joined this forum is search of support for my beloved xk8.A little history on the car,I purchased it a few months back and have already recieved a ton of help before I even joined this forum.So I go to look at this 2000xk8,first thing I noticed was its excellent cosmetic condition.They car only had 69,000 miles and had few noticable problems.Everything worked and functioned as new so I purchased the car.On the way back home on an empty country road I opened her up to verify the car was operating to its potential.later that day the car started kind of slow so I glanced at the voltmeter only to find it registering ten volts.My first instinct was that the high speed drive fried the alt and I proceded home to park her.As I drove the two blocks home the car started shutting down all the systems.By the time I reached my driveway it was in full limpmode running only the ecu.I removed the battery cable,installed a charger and ordered a high quality alt.When I restarted the car after making the repairs the charging light was on(never came on when it wasnt charging)and it had dropped a few systems like the heated seats,power mirrors and the auto tilt sometimes stops in random places (the tilt might be a seperate issue).So I hard reset the car and checked all the fuses only to find they where all good.I figured I would sort it out later and continued to drive the car.The next day on a cold start it was obvious I had some problems when the car was running ruff and posted a restricted performance along with a check light.I ran the codes and it was lean on both banks.My first thought was the plastic lines used for egr but to make a long story short I had to replace the intake gaskets.After that the car ran great for about two days then the check engine light came back on.This time is was a rich condition on both banks so I scanned the o2 sensors but they where showing an even range.I replaced the airmass and checked the fuel pressure under all conditions but the car still runs strange.Sometimes its perfect and other times it throws codes mostly around town and not on the highway.So thats where Im at now.I love the car and want to keep it but it needs to be sorted out.I figured this was the best place to start.

 

Ryan,

Your best place to start is in the new members section with an intro, then there is a good chance the admin will upgrade you to full access so you will be able to utilise the forum fully to your advantage without the usual post / time delay.

 

At 69K miles in twelve years, your XK8 has been lightly used and the condition you describe supports this.

Some further background is needed to indicate where the problem may lie. The service history and whether it was laid up for any length of time before you purchased it are both relevant to possible causes. Also the previous codes you cleared and the current codes.

Graham

 

Ryan, if you can't check for codes yourself, take it to Autozone or one of the others and they will check for you, make sure you get a note of the codes from them.

 

The car doesn't seem to have much service history unless someone removed it from the car.I can tell you that the service work was mostly done in the summer months (oil changes and such)other than that its just tire rotations and such.The car did come from up north.
The current code is a rich condition on the right bank and the previous codes where rich conditions on both banks.Every now and then it will show misfire codes on all eight cylinders.The previous stored codes I erased when I replaced the intake gaskets and they where lean condition on both banks and misfires on all eight cylinders.I have extensive datalog programs and access to almost any tools needed just not the knowledge of this particular car.I will follow through with whatever this forum asks of me.
Thanks

 

Do you have the specific codes? e.g. P0174

 

I just checked it again and its basicaly giving me the opposite of what it was this morning.
p0171
p0174
p1000
I am stumped.

 

Looks like a vacuum leak.
You say that it ran well after you changed the inlet gaskets, it's both banks so I'd check that something in the inlet ducting hasn't come loose or been damaged when you were in there.

 

You'd expect P1000 (system checks not completed) because you've recently cleared the codes.

P0171 = 'A' bank combustion too lean
P0174 = 'B' bank combustion too lean

Possible causes are:
misfire
fuel filter / system blockage
fuel pressure regulator low
fuel pump output low
air intake leak between MAF and throttle
HO2S harness fault
exhaust leak (before catalyst)
ECM receiving incorrect signal from one or more of - ECTS / MAF /IATS /TPS

You say 'opposite of what it was this morning'. Was it running rich and giving a P0172 before?

Graham

 

That is correct,the car was giving me rich on bank one and two codes before.I thought this to be strange so I installed the old maf and it gave me rich bank codes almost instantly.I then datalogged both new and old maf's,the old one was out of range making my fuel trims go negative and the new one was out of range making me go positive.I have a freind in the parts world that crossed the maf part number for me and we pulled a used one off a subaru(turns out to be the sam maf).The used maf was right on point and made the car run excellent almost instantly.So it turns out I purchased a defective part.
He also crossed a handfull of the parts over to lincoln ls,stuff like the valve cover gaskets.Funny some parts that show unavailable are on the shelf under other makes and models.
I guess now I just need to figure out whats wrong with the alternator light and the heated seats\power mirrors.I remember reading somewhere about a weak wiring harness on the core support?Could be anything after the car losing voltage like that.
I appreciate the help guys and I have a new confidence with the car running tip top.

 

You don't mention doing a load test on the battery.

These cars are very sensitive to a failing battery. The starter is perfectly capable of spinning the engine a voltage below the point where the electronics becomes erratic. They will also crank and run but with issues and give strange symptoms like you describe.

. . . and welcome to the forum!

 

I will have it load tested in the morning and recheck all the fuses before I go any futher.If I remember correctly the battery was good but the car does act funny.Sometimes the tilt will work with the key off and sometimes you have to put the key in.Sometimes the trunk light works and other times it doesn't.It never has any memory problems though.

 

So my car is running great since I replaced the maf then in my driveway idling it throws a restricted performance and a check engine light.Keep in mind the car is still idling perfect,when I pull the codes the damn thing gives me 1071,1072,1074,1075.Basically it set lean and rich codes within a two minute time frame with the car idling.I guess now I should be looking at connection points and ground wires?Kind of lost at this point.Maybe someone here has seen something like this before?