After a ton of work on my 97 XJR, 1500 miles plus driving. I still can not get all the monitors to a ready status.
Not Ready:
Catalyst
oxygen sensor heater
Secondary Air pump

Car is running great, idles very smooth. Trans shifts when it supposed to.
I have replaced Map ,egr, secondary air pump and valve, and all four 02 Sensors.
Pump blows hard and can see on the scanner that at start up its commanded by ecm to run for about 20 seconds which it does. Can see that the 02s start running more lean.
All 4 02 sensors are in the correct plugs.
No exhaust leaks, no vacuum leaks a very small oil build up at two of the spark plugs, a minor issue.
Exhaust blows out the tail pipe with what appears to be a "normal " pressure.
I have no DTCs
I cant even produce a DTC by unplugging a coil and driving with a misfire, Ive unplugged several plugs and can not produce a dtc.
Ive checked the connection at ecm , no corrosion or any signs of fouling.

Any ideas?

 

Ideas, no more than that!

Is the car running in "closed loop"? What are the LTFT and STFT values? Does the car idle at 750 rpm? And, I do not recall a drive cycle test for lambda heaters. Is that what you are referinfg to?

Although failed ECUs are seldom reported, it sure sounds like you might kust be on the right track.

 

Yes, Car is running in closed loop, The short and long were a lower number, will give you exact tomorrow. The long I remember was positive 2.34 as it didnt fluctuate like the short terms. They did react to vacuum leaks I made.

The idle is right in the 750 area, with no feeling of any misses.

The lambda heaters are what i am referring too, it shows as one of the monitors that are not ready yet

I am using a Snap on Solus scanner and Auto Enginuity with the jag enhancement

 

Well. I would say its time to get the meter out and check the lambda heater circuits for power. I don't think AE gives lambda heater indication on the X-300, does it?

 

STFT B1 FLUCUATES -10 -6

STFTB2 -9.3 -6.2

LTFT on both banks is a constant 2.3.


On the four wires coming from the 02senosrs i get

14v
.9v to .2
.3v constant
0 v constant

all the 02 sensors are the same readings.

Lambda fuse is good

thanks, still need ideas

oh, i did notice in the wire harness that runs along the firewall to the down 02 conectors I have 4 thin wires that go no where. theres no missing plugs and no wires for it to connect to.. Im thinking possible wires for egr temp sensor which I cant find on this motor??

 

Yoor STFT is pretty negative, When you say you replaced MAP, you mean manifold pressure, right? I would clean the MAF if you have not done so. I think gatting the STFT to nearer zero should be your first strategy.

BTW, there isa condition that the ECU gets into where it will not update the LTFT at all and will not complete a drive cycle. In my case, it was also preventing the ISSC idle system to correct idle. I have seen reference to this condition occasionally on a forum, but have3 never seen any published documentation acknowledging it.

I think your snap-on will do a "O2 re-orientation". It can't hurt to try that.

 

The Snap on will only communicate thru obd2 standard. I looked thru all the settings and cant find O2 re-orientation.
I did clean the MAF, also changed it off my xj6(97 as well) and made no difference.

checked alot of wires. Found nothing. Checked every vacuum hose, found nothing.

Swapped the exhaust out with xj6 s and still got nothing(xj6 exhaust a little bit smaller) still no changes. Of course swapping it back I snapped two of the studs and had to tourch one and drill out the second.

Checked the ecm part #s and it had the prom replaced back in 2002.


Sure wish I had a DTC.

What kills me is that it probably wont idle as well as it does when I do find the problem

 

well, now ive created a new issue, wrote last message before road testing the vehicle again.
Road tested before swaping to old 97 exhaust was fine. Old 97 exhaust felt like a clogged catalyst condition. So i put back on the origional exhast system that it drove fine with.
All o2 sensors were labeled very clearly and double checks with snap on scanner and Alldata id label of 02 sensors.

It drives with the origional exhast like a clogged cat condition. STFT is now at 24 positive at start and flucuates 0 to 24. 02 sensors apear to be acting exactly the way bfore .

rrrrr

when it rains it pours

 

Did you put the supercharged Mass Air Flow meter back on? They are different Supercharged vs Naturally Aspirated.

 

Yes, the one that came with the XJR is still on, Does have the same part number on it as the xj6.

Found out yesterday that the throttle acuator( located in between both throttle cables) is bad. Swapping out tomorrow with the xj6 if both are the same. Memory telling me that the cable from acuator to throttle linkage is different.

 

All my research says those MAFs are different and should not have the same part number. My best estimate would be that the supercharged one is calibrated for more air-flow.

And if my memory serves me correct then I think you are right about the actuator cable is the same from the pedal to actuator but different to the t/body.

 

MAFs are different Part #, when I purchased the car the previous owner must have changed with different. ITs on order now. Thanks

 

Changed out the throttle acuator using the unit from the 97 xj6 with the cables from the xjr. Car has the power back but now have the traction control light on full time. No DTCs. when i start the car it goes out for less than a second and on full time??

Car also passed state emission inspections today!! Very happy with that

 

A standard OBD scanner will not read the ABS DTCs. You need AutoEnginuity, SnapOn, Autologix?, or the dealer level IDS or WDS.

 

Snap on will only read from ecm and trans mission module, wont access abs module

the AutoEnginuity says theres no codes in the abs module but on different test of live data says there are four "4 permanent codes".

Hoping to find a wds scan toool soon

 

The two wires that go into the bottom of the throttle acuator appear to have been spliced in a very poor way, they stripped away almost 3/8 of the insulating plastic right before the plug connector thats strapped to the mounting bracket. Wires were touching causing no traction control. All fixed now.