Does anyone know the correct TP% value for a Disco 1 at warm idle? I'm showing a constant 14.1% - it rises as I give it throttle up to 90% or so but never falls below a consistent 14.1%. I've checked and the butterfly plate is closed.

I'm running ridiculously low mpg (in the 8's this week but it has been short round trips). My LTFT was at 13.1% but it has since dropped to 3.1 and then up to 14 and then down now around 5.5% LTFT.

I put in new:

Upstream 02 sensors
New Fuel Pump
New Fuel Filter
New Plugs
New Wires

Fuel Pressure seems to be within specs and only drops after sitting for awhile.

Idles nice and smoothly (around 700 as I recall but might be slightly higher)

My logic is that if the TPS is reading 14.1% at warm idle, when it's actually closed, then the engine is dumping more fuel than necessary --- but that's just a guess.

If someone has a Disco1 running proper and showing much better mpg and you can tell me what your OBDII reader shows the TPS at I'd appreciate it.

Also - while I haven't found a shop to do a smoke check for vacuum leaks, I have gone over every tube there is and squirted carb cleaner around and haven't identified anything obvious.

Top end rebuilt and sealed 20k miles ago.

 

IIRC mine TPS reading at warm idle is 11%. So yours doesn't strike me as way out of range.

 

Thanks, Walt. I'm having a hell of a time chasing down wildly fluctuating LTFT numbers and atrocious mpg (even for a lifted Disco). The LTFT changes weekly - now it's at 6.5%, the short term fluctuates as it drives up and down.
















I also have an issue with a replacement non-AEL cap being almost impossible to remove (have to use channel locks) and when I do get it off air whooshes out of the tank. I've read that on other vehicles that can be a bad EVAP but I'm not throwing any codes. I ordered a replacement (used) charcoal canister and purge valve to see if that helps, which could be tying into the crappy mpg issue too.

 

It's fine, it's poor way of reporting the data from the scan tool. It's percentage of the total resolution of the input. 11% is .55 volts. I've seen GEMS adaptive TPS closed values close to 1V, so I'd say as long as you're under 20% it can figure it out.

 

I'm running 12.1% at idle. 680 rpms.
Hope that helps