New day, new problem, basically i was trying to locate a misfire on my engine, was checking sensors, wiring, injector harness , pulling wires in and out, checked MAP vacuum line, fuel pressure vacuum, etc. During this work i started to get FF19 error on the computer, didnt really pay much attention, though its happened because i disconnected and reconnected smth, took car for a drive and it doesnt want to, it want to stall on D , unless i give it a bit of gas, doesnt run above 1500 RPM, i managed to get home literally by just slightly giving a gas and keep it bellow 1500, now i start to think this Code does mean smth, its doesnt go away after battery disconnected.

i found only few threads about it and still cant understand what exactly this code refers to, what i found is , its either MAP or TPs or smth else.

my ECU is 26CU , 1992 XJS 5.3 v12

Thanks for the help

 

What’s smth?

FF19 is map sensor.

All FF codes are F for fuel system.

did you disturb the TPS at all?

Where are you located?

 

Consider buying this manual.

https://mossmotors.com/jtp1007-cp-or...blications-xjs

 

oh thanks, so first think I should be checking is TPS voltage? I actually didn’t touch TPS , when it says map sensor, it means the one in CPU right?

manual ordered

 

So the easy TPS check as usually turned to a nightmare

First of all, my TPS doesnt have yellow, red and green. Instead it has red, green and black.
please see bellow


if i assume red is red and green is yellow , then V goes from idle - 0.24 to WOT 0.03
if i assume red is red and black is yellow, then V goes from 2.6 to 4.6

 

That black wire appears to be marked with a yellow band.

Paul

 

0ne wire carries a permanent 5V.
The wire with the variable voltage is the wire that gives the ECU the throttle signal. This should be 0.32v at closed throttle and 5v or 4.9 at wide open throttle. You adjust it by loosening the screws and turning it slightly one way or the other. Once the closed posotion is set that is it.

See attachment to post number 10 on this thrrad for the loom/tps wire colour match ups

https://www.jaguarforums.com/forum/x...engine-268012/

 

thanks Greg, apparently on my Lucas 215SA TPS , green is throttle signal, black is ground and red is constant 5v
However, now im a bit concerned, i have seen few threads were its says that facelift 1992 5.3 TPS should be at 0.20, not 0.36. How can i confirm this?

Ok so my TPS was at 0.15, i set it at 0.36. And then car gave me 4 different codes each time i reconnect the battery
FF19, FF17, FF13, FF23. Last one seems to stay and repeats.

i have checked the MAP vacuum hose - clean.

 

checked ECU grounds, checked CTS, Air temp sensor, TPS set at 0.31. Still im getting 17,19 and 23 code, when i put car in drive sometimes RPM starts to slowly go down to 0.

 

Update: in case someone will get into the same problem.
MAP vacuum taken from cross pipe at idle ( 16 inHG)
MAP vacuum taken at metal spigot at the trunk (10 inHG)

looks like i have a vacuum leak somewhere between crosspipe and ECU , if im thinking it right.

Update: Guess where my vacuum went?


Problem resolved! I hope that was the reason for overheating and bumpy idle.

 

Whoa, where on the car did you locate that breakdown? Fingers crossed this solves your issues!

Cheers