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Running rich and cutting off - guys, check my OBD data, please.
Hola! Now its my time to complain about my car. 3.2L XJ6. Looks like i`ve been having almost all the standart issues, but anyway, I would love to hear the communities opinion and maybe you can look at my obd graphs below.
So, the car is pretty much gutless, especially from low to mid range rpm, uses a lot of fuel and is running rich. It steams like a steam boat even when engine is in operating temperature and exhaust reeks of fuel (its not the white clouds of burning coolant, I know the difference).
What I know about this car, is that the gearbox has been changed some time ago, so I presume that, maybe, the O2 sensors are not plugged back in a correct order and that a car has an exhaust leak somewhere around gearbox, but the leak is after the O2 sensors (equipped with two), and probably it has a small leak somewhere around manifolds or downpipes.
The other thing is that it loves to shut down itself at pure random. For example, yesterday I was idling it in my backyard just to to get the engine in operating temperature for my OBD tests, and it just shutted down as if somebody would just turn the ignition off. No sputtering, no coughing, it just shuts down. And its happening from time to time. Cold, hot, driving or idling, it doesnt matter, it just happens from time to time, with no pattern at all. When I`m trying to fire it up again, nothing happens. The engine is not turning. I can flick the key 100 and 1 times and nothing. Sometimes she starts after the battery clamps are removed and then put back again, sometimes she starts right after the shutdown, with first try, sometimes it takes a bit more of cranking to start the car up and she doesnt want to idle properly, I need to hold my foot on an accelerator pedal. The car does not have an aftermarket alarm system, it has an original central locking and alarm. My Delphi OBD scanner found an fault code with a number "P1621". It shows up after the car died. I erased it and then it popped back again, when the car died again.
Ok, here I uploaded my OBD graphs. These are from idling and revving an engine when standstill, `cause my laptop`s battery is dead and I can`t take it for a spin. Also, what spots for a possible vacuum leaks should I check?
Also, I`m not an electronics guy, I can fix mechanical issues, but all the stuff around sensors, wiring, relays and such stuff is a very dark picture for me.
Some times the inertia / crash switch acts up and can be jumpered with a paper clip on the 2 white wires .
The BT4 connector above the fuel tank can come loose as the engine needs a signal from the trunk mounted security module . Looks like pic below . They can be hard to reconnect but don't try too hard and break the lock pins . Once connected you can tywrap the locking bar closed like mine when I got her .
When you remove the O2 sensors from the pipes keep track of each ones hole position in the pipes as this confuses the ECU beyond the earlier discussion of the connector positions .
Last edited by Lady Penelope; 03-25-2018 at 11:53 AM.
Looks like your O2 sensor on Bank 2, reading the STFT is not working. It should be "switching" like Bank 1 STFT. Bank 1 at .8% is good. The O2 sensor gives fueling feedback. A failed O2 sensor could cause the over-fueling, poor running, and would probably give you some related engine codes. You need a new O2 sensor for sure.
The throttle position (TPS) at 11.2% is fine for an idle reading. It is shown to be reading higher, along with higher engine speed as the accelerator is pressed.
The last graph shows the MAF at zero. Was the engine running then? An intermittent MAF would likely cause stalling. Again, we would hope for an OBD code in that case.
Be sure the spark plugs are correct, Champion RC12YC at .038" (.96mm) gap, the gasoline is not contaminated with water, and the throttle body and EGR valve are reasonably clean.
Looks like your O2 sensor on Bank 2, reading the STFT is not working. It should be "switching" like Bank 1 STFT. Bank 1 at .8% is good. The O2 sensor gives fueling feedback. A failed O2 sensor could cause the over-fueling, poor running, and would probably give you some related engine codes. You need a new O2 sensor for sure.
The throttle position (TPS) at 11.2% is fine for an idle reading. It is shown to be reading higher, along with higher engine speed as the accelerator is pressed.
The last graph shows the MAF at zero. Was the engine running then? An intermittent MAF would likely cause stalling. Again, we would hope for an OBD code in that case.
Be sure the spark plugs are correct, Champion RC12YC at .038" (.96mm) gap, the gasoline is not contaminated with water, and the throttle body and EGR valve are reasonably clean.
Thanks, Sleek`!
Yes, the car was definitely running. And no, no OBD codes, except P1621, that I mentioned already. I will hunt down possible exhaust leaks with new donut gaskets. I haven`t changed the spark plugs (actually, I haven`t done any of the maintenance thingies yet), that will happen this weekend. As I`m from Europe, no EGR on my car and only 2x o2 sensors.
Heres another graph that I recorded driving the car. All four volumes are from the same record.
Yes indeed, sensor B isn't looking good. It would be wise to replace them both. I'm not certain about the MAF, whether it would occasionally read zero while the engine is running (for example at idle). But it seems like it is cutting out even though the engine speed is up. Suspicious. Check all plug connections for dirt and corrosion. Spark plugs and new O2s first. Then see how she goes. Time to get some Jaguar dirt on the hands!
Hell yeah!
My first Jaguar and its already broken.
What o2`s manufacturer/part code to look at? Bosch are any good (I can get them a bit cheaper than normal)?
I tried to disconnect the MAF while engine was running and the engine started to sputter and run uneven, so I could believe, that it`s still alive, huh?
Nevermind about the TPS, I didn't read the graph correctly. 11.2%, while a bit low, is where I think I'd rather see it anyways. (Normal is 12.9% at idle)
Your Bank2 is clearly off. Your STFT Bank 1 looks like it should. Bank 2 is what it should not look like.
Guess what Bank Oxygen Sensor B controls...
You need new oxygen sensor. I would do both of them at the same time.
If you have nothing but time on your hands, you could swap out sensors and see it go over to the A side.
Bosch, NTK and Denso oxygen senors are all made by NTK. I've bought them all, and they all have the same NTK stamp on them. They could have different specs, but they are all made by the same company.
Your MAF seems fine. It goes to zero when the TPS is at idle, so that would make sense.
Check your echaust manifold (take the metal shield off) when looking for leaks. They are known to crack.
O2 sensor location pic I said I was going to do yesterday :
The cylinder # 1 is the fwd one and is opposite of the earlier AJ6 engine . Bank 1 is always on cylinder 1 and sensor 1 is always closest from the block
Clean the 3 grounds terminals along the upper firewall inside the engine compartment as the 1 sensor and 2 sensor have different shield grounds . The O2 signal is very sensitive as it carries intelligence and not power .
Be carefull to not damage the donut gasket seat on the downpipe with the manifold studs in the heat of battle . The manifold has to be on first , no side clearence . The inside nut has to be taken off with a 15 mm and 15 degree offset . You can partially install the extension into the socket and get your 15 degrees .
Your MAFS readings look far too low - I don't believe it should ever read 0 grams/second with the engine running. A general rule of thumb is that the MAFS reading at idle in grams-per-second should be approximately equal to or a little greater than the engine displacement in liters, so at idle yours should read something like 3.5-5 g/s, and it should rise from there to 30 g/s or more at higher revs, whereas your maximum reading is just 0.4 g/s at 23.5% absolute throttle position.
It would be worth checking the electrical connector at the MAFS to be sure it is clean and properly secured.
Regarding P1621, that code does not show up in any of the X300 DTC Summaries manuals I have, so it may not have been implemented on the X300 and may just be the result of your scanner trying to make sense of data it doesn't understand.
The MAF as a voltmeter DC reading at idle on the zzz wire should read 1.7 volts going toward 5.0 on throttle up from the reference voltage ( Blue / White ) of 5.0 volts ( worth checking ) . 4.0 grams / second is the true unit value at idle going toward 165.0 on throttle up . Some data readers have a MAF reading error of 10 or 100 times so just multiply your readings to make sense .
The TPS at idle should read 0.60 volts on the center wire ( Green / Pink ) from the same reference voltage of 5.0 at wire Z . This value goes toward 5.0 an throttle up . Put your hand on the throttle butterfly tower as they mechanically bind from full closed stop that we'll look at later . Don , this is where I get the problem of the B+ reference power sourced from the ECU relay or fuse Editing
You can remove the connectors on tied in ( by wiring ) sensors and see if other sensors beyond the target one is sucking the ECU return intelligence signal down . If the ECU does not see a return or is out of range it will reject the return signal and revert to a less them optimal set maps or data arrays in software terms .
Vee , if I remember correctly had a proven suggestion of twisting the pins / blades to make better contact .
Check both reference voltage wires and ensure they are exactly 5.0 volts , and if not swap the # R5 ECU controlled relay with the # R3 AC clutch relay . My ECU controlled relay had a nick in the insulation on the X wire under the relay socket .
Have you cleaned the 3 ground terminal post on the upper back wall of the engine compartment ?
The Bank 2 sensor is wacked and its intelligence wire shield ground is the Y terminal on that back wall .
The O2 sensors have to be heated to some point to function by the O2 sensor heating elements until the exhaust heats them up . This can throw you off in reading a cold startup engine if the heating element is out . To test the sensor heating element put a meter on the Blue / Pink to the White / Green wires on the sensor side of the connector and both should read about the same resistance . Correct and proofread this part
Editing in the morning
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Last edited by Lady Penelope; 03-27-2018 at 09:27 AM.
I'm not in a position where I can immediately test this, but I do believe I get a zero reading from my MAF at idle as well. I will report back as soon as I am able to confirm.
About the MAF - when I was taking off my intake, throttle and big rubber elbow before throttle body was full with brownish, Nutella like goo. Maybe the MAF is clogged with it? Is it ok to somehow clean it with brake cleaner or something?
About the MAF - when I was taking off my intake, throttle and big rubber elbow before throttle body was full with brownish, Nutella like goo. Maybe the MAF is clogged with it? Is it ok to somehow clean it with brake cleaner or something?
It is common that the intake would be in this condition as the original design of air/oil separator . My intake air temp sensor right on the top side of the 90 degree turn in was this same way .
Recommend only use a product labeled as MAF cleaner as other products can harm the MAF sensor
I don't have the above post edited yet and some of the wire colors will change . Will be searching the salvage yards for parts today so it may be later tonight .
The 02 sensor section I wrote is correct and the heater power source is a single fuse for all and the grounds are in the ECU . The heater power source wire White / Green goes through the Papa Indy 61 connector position 12 under the windshield washer fluid fill cap . And the fuse is # 14 / 10 amp RH engine fuse box and the grounds inside the ECU has one for the upstream pair and one for the downstream pair .
It is a good idea to inspect and clean both Papa Indy 1 and next to it 61 connectors as many engine things run through them and I have a parts source if needed
Last edited by Lady Penelope; 03-27-2018 at 09:48 AM.
The MAF as a voltmeter DC reading at idle on the Green / Pink wire should read 1.2 volts going toward 5.0 (? ) on throttle up from the reference voltage ( Blue / Light Green ) of 5.0 volts ( worth checking ) . 4.0 grams / second is the true unit value at idle going toward 165.0 on throttle up . Some data readers have a MAF reading error of 10 or 100 times so just multiply your readings to make sense .
The TPS at idle should read 0.60 volts on the center wire ( Green / Pink ) from the same reference voltage of 5.0 at wire Blue / White . This value goes toward 5.0 an throttle up . Put your hand on the throttle butterfly tower as they mechanically bind from full closed stop that we'll look at later . Don , this is where I get the problem of the B+ reference power sourced from the ECU relay or fuse Editing
You can remove the connectors on tied in ( by wiring ) sensors and see if other sensors beyond the target one is sucking the ECU return intelligence signal down . If the ECU does not see a return or is out of range it will reject the return signal and revert to a less them optimal set maps or data arrays in software terms .
Vee , if I remember correctly had a proven suggestion of twisting the pins / blades to make better contact .
Check both reference voltage wires and ensure they are exactly 5.0 volts , and if not swap the # R5 ECU controlled relay with the # R3 AC clutch relay . My ECU controlled relay had a nick in the insulation on the X wire under the relay socket .
Have you cleaned the 3 ground terminal post on the upper back wall of the engine compartment ?
The Bank 2 sensor is wacked and its intelligence wire shield ground is the PIG153L terminal on that left side back wall .
The O2 sensors have to be heated to some point to function by the O2 sensor heating elements until the exhaust heats them up . This can throw you off in reading a cold startup engine if the heating element is out . To test the sensor heating element put a meter on the Blue / Pink to the White / Green wires on the sensor side of the connector and both should read about the same resistance . Correct and proofread this part
Editing
Last edited by Lady Penelope; 03-28-2018 at 08:48 PM.
Update to my topic.
Car is now in the hands of a body shop, the rear arch will be welded in.
From my home to the body shop was a trip of some 100km. Before the roadtrip i`ve located very badly corroded bulkhead positive terminal. Cleaned all the nuts, positive wire, thread itself with the sandpaper and sprayed it with contact cleaner. Also removed rear ground wiring that attaches to the battery and the cars body, and gave it some good cleaning. The car didn`t stall not a single time on my trip. Everything was perfect. I just hope that the reason for stalling and cutting off really was the bulkhead terminal.
While my car is beeing welded and painted, I would like to buy the O2 sensors - can you point me what sensors I need? There are some NKG sensors (two types - one with the clip on connector, and other with just bare wire. I don`t want to solder the connectors, actually), and one Bosch type.
Any codes and/or part numbers?
The O2 sensor wires are galvanized coated and don't take soldering ( I never could get it to wick into the threads even with flux cleaner ) so in my opinion I would go connector ready .
Sometimes one seeks the magic bullet of an item to change when it is the foundation of the system , grounds are just as important as any thing else .
One ground stud that is important is the one by the starter other then the positive post for the starter . Not easy to get to or tool cambinations .
Last edited by Lady Penelope; 03-30-2018 at 01:16 AM.
Long time no see, friends. Partly solved my problem. Welded my exhaust and put in new O2 sensors and vuala - no fuel fumes from exhaust and the consumption is fairly reasonable now. Still very, very slow and not picking up speed though. When I floor her she picks up like a minivan with a dead engine, when the RPM reaches some 3.5/4k rpm, then she flies suddenly.
Car still cuts off at pure random. When cranking, the tachometer does not move. So I guess new Crankshaft Sensor it is then, will order it soon. And still sometimes its just not cranking after shutting off, I can flick my ignition on and off for 50times and then, suddenly she just cranks and starts instantly.
Tried to solve the random cutoff problem and took the following steps - disconnected the two connectors in the engine bay next to window washing reservoir. They were perfect, no corrosion or oxidation at all, sprayed them with the contact cleaner just to be sure. Next I removed my ECU to see if the connectors are okay - they were in splendid condition, no corrosion or dirt, all new and shiny. Also cleaned them with the contact cleaner. Then removed the security module from the left hand rear wheelarch. Opened it up to see if the plate or chips are corroded. Nope, everything is in perfect condition. Cleaned the connectors and re assembled. My suspicion now is the main Igniton Relay which could cause this random havoc of shutting down. Oh yes, how to check if my immobiliser is ok and working?
Just a minute ago I was sitting in my car and playing with my diagnostics tool, the car`s igniton was turned on in first position (all sistems operational, but engine off). The regular lights of low oil pressure and battery not charging were on (of course, because engine`s off), and then, just at pure random, my Check Engine light turned on. It never happened before (not that i`ve noticed). My diagnostics tool found no new fault codes, except the common one P1621 - Immobiliser Code Words Do Not Match. When I started the car, the Check Engine light was gone.
03-25-2018, 10:08 AM
Running rich and cutting off - guys, check my OBD data, please.
and its intelligence wire shield ground is the Y terminal on that back wall .
