I bought a used FTPS sensor off eBay and it reads the same. I will keep it for spare. Put original FTPS back in.
Put in new gas. Still rough idle around 700 rpm.
back to square 1.

 

Yes, I have seen errors in the electrical guide before. If you look at the 2003 guide it says "voltage increases as pressure increases" so it looks like they corrected the documentation.

 

I cleaned MAF sensor with MAF spray cleaner, cleaned contacts with QD cleaner. Car idles at 700 , no issue. However MAF reading is .44 lb/M. short term fuel banks are both +25%
upstream O2 sensors have very little movement. I cannot read the voltage with my device only current
What is going on?

 

Sorry if I’ve missed it, but have you replaced the MAF sensor with an OEM unit and done a hard reset at that time. Unlike the 4.0 XKR MAF’s, the 4.0 MAF is not expensive and is used on different cars IIRC,

Z

 

I forgot to mention I did the hard reset after cleaning it.. I will look at getting a new one.

 

The MAF is under reading by about a half (if my conversion from pounds to grams is correct). This would explain why the computer is maxed out at +25% fuel. I'm guessing your O2 sensors are maxed out also.

The upstream sensors return a current value, which should be in the range -128ma to +128ma.

Try unplugging the MAF and see what happens.

BTW if you live somewhere that requires monitors to be set to pass emissions testing, never do a hard reset.

 

if MAF is defective, how should the engine respond if I disconnect it?

I have had issues getting monitors to be OK years ago. Tedious driving routines.

 

never is a long time (from what little I know about time). I’d suggest not doing the hard reset if the car has to be tested for emissions right away.

but if you don’t need testing, or don’t need it in the near future, then yes, by all means, do the hard reset reset.

Z

 

engine died when I disconnected MAF.

 

this MAF does not have typical DENSO part number

 

That looks specious. I think I'd replace it, if only on general principles.

 

anyone know DENSO part number and where I can get it?

 

Yep, you want the genuine appropriate Denso MAF sensor. Too many poor-quality fakes out there....

 

From Densoparts website
https://www.densoautoparts.com/part-...ssRef=197-6040

Rockauto has them
https://www.rockauto.com/en/parts/de...f)+sensor,5128

 

used part on Ebay has a different Denso number

 

LNE1620CA has been superseded by LNE1620CB, so it's an older part (although it may still be working OK?).:
https://parts.jaguarlandroverclassic...ow-sensor.html

See this post from scottatl:
https://www.jaguarforums.com/forum/x...5/#post2122497

 

thanks very much for the help
bought it on AMAZON

 

tbsts the same MAF some ebayer tried to sell me as correct for a 4.0 XKR..

not. And not correct for your XK8 either.

Z

 

And unfortunately "never" is how long it takes some people to reset their readiness monitors. People need to be aware that a hard reset isn't some magic cure all that fixes all problems, it can in fact introduce a new problem that will make their car impossible to get registered depending on where they live.

More people need to understand this.

 

See what results you get with the replacement MAF. If the car won't run without the MAF connected, it does suggest problems elsewhere. Has the car got the original airbox and filter and when was the air filter last changed?