All,
I have an issue with my S type. The engine control is not working well when I turn in right.....(imagine the jokes generated by the brain of French people about a car that do not drive, in UK, in the right side that can't turn left...)
Initially, I thought about fuel issue (first contamination, fuel pump later) however, the fuel pressure reported by the OBD when driving is stable and correct.
The ECU does not flaged a DTC (diagnostic code) even if they are 3 tests that failed (reported by mode $06). My OBD software had linked the failed tests to the Test Identification and Component Identification:
TID CID
53 7
54 0
56 0

I have no idea of the parameters that are under control with those tests.
Could somebody help?
Thanks,

 

i'm just trying to understand your problem, is the engine cutting out when you turn right ?

 

If those are misfire TIDs (as I think they are), be careful how you interpret the values. May be best to ignore them. I don't see how they would help with the problem.

Please try a simple explanation of the problem. I also do not understand what is wrong.

 

My issue is when I turn on right (not at low speed, but like on motorway access) it is like when you do not have fuel on carburator engine. you need to drive fews meters (some 100 to 1000m) before the engine works propelly and the fuel come back.
If I turn slowing on right, nothing happen. On left, again, nothing bad. On smal local raod, no effects. The typical effect is when I turn on right to acces to motorway (yes I know, for you in UK, you turn on left, it why probaly the Jaguar was designed....) or on motor way on larges curves. I really needs lateral accelaration to trig the issue.

I thought about fuel pressure issue. I oppened the fuel pump, every thing looks ok..... The fuell tank was full and the pump is in a midlle of fuel, I do not understand what could happen!!!!

I made measurement with OBD monitoring the fuel pressure. This parameter is very stable, even if when the engine does not work properly.

Graham (GGG) written:
"Presumably there's no pending or stored DTC's (Diagnostic Trouble Codes) and that's the reason you opted to go direct to Mode $06 TID (Test Identification) and CID (Component Identification) raw data?

The description of the engine fault sounds like temporary fuel starvation, especially as it must be below the mandatory threshold to set a DTC. "
He's right no DTC, but not fuel pressure issue either....
They are only out of range values reported by the Mode $06 TID (Test Identification) and CID (Component Identification) raw data.
However, I have no idea of what are those measurements.
Is there somebody who know what are tthe following TID and CID:
TID CID
53 7
54 0
56 0

Thanks,
Richard

 

Very strange issue, can you explain more,


When making hard-right handed turns, like when hitting the on-ramp,

You get what feels like fuel starvation,

Does your engine go to 0 RPM and you lose all accessory?

You then coast straight down the road a distance and the engine restarts itself again automatically?

Or do you come to stop and have to key in START the car from fresh?

It sounds like a fuel issue for sure, but you're getting pressure.

You should inspect your fuel injector wiring loom (harness) thoroughly,
you should also find the wiring diagram related to the fuel injector harness,
the harness will have a ground wire running through it to a ground point on the chassis at some point, check that for any issues,

Anything electronic driving the fuel injectors, its wiring/ground should be looked at.

 

my issue looks exaclty in a same maner if the fuel become bad. I do not have any switch off circuit, evrething seem to be power supplied properly.
I worked on the harness and at idle, I moved all the cable without trigering the issue.

I understand that teh injectors are comanded rank by rank. In another words, if I have an issue with injector control (by the pcu), I would have on 4 strokes, not on all. An harness issue would aslo affect only one injector. Due to the magnitude of the issue, all the storkes are affected, but it is not like a switch of/on but really like lake of fuel pressure (but the data is reported as to be correct by OBD) or due to engine fuel management issue.
More and more I think that the issue is relly fuel management. UI assume that a wrong parameter is used to command the fuel (injection duration) in an inapropriete range.
It is the reason why I would like to know the parameteres that are reported as to be out of range (refer to the TID/CID measured).
Saying that, I have to confesse that I don't know what is the real issue, it is why I didn't fix it yet..... I would be a poor intermitent contact somewhere.....
BY knowing what are the parameters out of range, I would more focus around the parameter, the sensor under control by those tests...
Thanks for your thinking,

 

I can't see how it could be the fuel pump.

I'd ignore mode 5 (and 6).

You could be losing vacuum in which case monitoring MAP would be more useful and doesn't need weird mode 5 stuff.

You might also have a chafed wire.

Whatever it is, you say it only happens at certain times so that rules out those mode 5 things. Please focus on much more basic & simple things!

 

I have some data to share. How can I attache an xls file?

 

I don't know anyone who'll look at xls in case that helps.

 

I attached an xls file that is a record I have.
At 130 sec, I have an issue. (marque 1 into the file).
All the parameters are ok. However, we cant notice that the engine control goes in oscilation mode. It is like the system had an over shoot and try to recover.
The mass flow is in line with the buterfy. The O2 is also ok.

 

Quite possibly your jet pump is intermitient or faulty... (Your MY S Type has 2 fuel pumps - a main pump and jet/transfer pump)

 

The fuel presure is very stable. Take a look on the data reported by the OBD during the issue. The fuel pressure measured by the engine control computer is stable, that means that the pressure is ok, teh sensor is ok and the computer measurement also ok.....

 

As it only does it on certain right turns surely anything to do with the fuel tank or pumps is simply not relevant.

There is almost for sure some harness routing or common wire/connector that COULD be the cause. The electrical guide shows far more detail than people tend to notice, due I think to glancing at it too briefly. I would study the parts involved but I might first go hunting on the actual car.

I'd check both sides of each circuit i.e. power & ground. Many times people forget one or other is shared at least some of the way. Again, shown in the guide.