I have an 05 S TYPE R that at about 4 k rpm heavy throttle the ECM is turning off the duty cycle to the rear modules after a clattering and misfire. The codes are for misfire B Bank 2,4,6,8, and random and excessive misfires.
fuel trim
stft 1 stft 2 ltft 1 ltft 2 stft 1 down stream stft 2 down stream idle
1.96 1.18 15.29 11.37 .39 .39
at shut down
.39 .39 .39 .39 .39 .39
02 readings idle
b1s1 b2s1 b1s2 b2s2
.75 .75 .21 .09
at shut down
.01 -13.62 .08 .97
equivalence ratio
b1 b2
1.01 1.01
at shut down
1.01 1.01

 

With those LTFTs you look to have quite an air leak - if they head towards 0 at (say) 2500rpm in P or N. If they don't then post more (could be blocked cats but can't say yet).

First thing to check, find & fix.

 

Fuel trim @ 2500 stft 1, 5.10,stft 2, -3.53, ltft 1, 2.75, ltft 2, 1.18,stft 1 downstream,-0.39, stft 2 downstream -0.39, and i failed to mention lean mixture code bank 1

 

You can ignore all those STFTs. Need to fix the LTFTs by fixing what look to be the air leak(s). Usually the filter box, filter, trunking or etc - there are a lot of potential places.

 

I will let you know what i find

 

In expanding on jagv8's air leak...check connection where the brake booster line connects to the intake manifold, tube connecting EGR to passenger side exhaust manifold. This has been problematic for many Jags, including mine.

 

propane revealed no intake leaks and intake bellows and air box are intact

 

Have you checked the fuel pressure at the fuel rail?

 

I do not have any information on the 2005 STR but on the XKR it has 2 pumps. Do you know if you have 1 or 2 pumps? One of your pumps may be failing.

 

I have and compared it to specs reading with IDS and Autologic on both tools it remains around 54-55 psi at idle in park and full throttle while driving, the specs i found state 42.5 idle and 72.5 full throttle. at the rail idle in park 44 psi full throttle 80 psi. note this my o2 readings are a bank 0.01 and b bank-13.0 just prior to pump shut down.

 

2 pumps, ECM supplies duty cycle to RECM and to #2 fuel pump module and the duty cycle from the ECM turns off until it regroups

 

Gus - the STRs have 2 pumps, each with a driving module.

Air leaks.... gotta love 'em

 

found no leaks

 

All S Types and Lincoln LS's have 2 fuel pumps. One is a "Jet" pump which only transfers fuel from one side of the tank to the other to keep the levels about even. If this fails the car will usually run out of gas with a 1/4-1/2 full fuel tank.

The second pump actually runs the engine and is controlled with a PWM signal so the pump speed is variable depending on fuel demand. Older cars would cycle the pump off and on.

The STR has a completely unique fuel system with both pumps feeding the engine directly and above 3000 rpm they both run full blast.

I don't know how to properly test the STR system for correct fuel delivery under full throttle?? I don't know what the symptoms would be if only one pump was running but I think you would go lean as the engine outruns the capabilities of just the single pump?

Are you sure the pump does shut down and is not running?
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What are the codas you are getting, not what they mean?

 

P0171,p0300,p0302,p0304,p0306,p0308,p1314 & p1316

 

Fuel trims say you have one or more, don't they. Just not found. The lean and misfire codes confirm it. Unless you have another theory which fits the facts?

hmm, would a blocked cat or air leak into the exhaust (cracked manifold/whatever) do the same?

edit: one blocked cat / exhaust leak might explain some of the problems but both sides have high LTFT so looks like an air leak and quite likely another problem as well

 

OK!

The P0171 = Engine misfire Air intake leak between MAF Sensor and cylinder head Fuel filter / system restriction Fuel injector restriction IP Sensor fault (low fuel pressure) Low fuel pump output HO2 Sensor(s) (1/1, 1/2) harness wiring condition fault EFT Sensor fault (low fuel temperature) MAF Sensor fault (low intake air flow) Exhaust leak (before catalyst) ECM receiving incorrect signal from one or more of the following components: ECT Sensor, MAF Sensor, IAT Sensor, IP Sensor, EFT Sensor, TP Sensor

The P0300, P0302, P0304, P0306 & P0308 = Are cylinder misfires and the P1314 is telling you that you had a(and in this case several) cylinder misfires.

The P1316 = Misfire that is related to the above cylinder misfire.

I believe your car went into Restricted Performance. I would recommend that you begin looking for a leak in your system. That P0171 is telling you something, do not over look the importance and do not over analyze the problem. This might help http://jagrepair.com/images/AutoRepairPhotos/P0171.pdf You could have an MAFS, o2 sensor failing or a cat failure put I would be looking for a leak first.

 

Time to take a breather...... Lots of input here, some of it misleading.

For 2005:

XK8/XKR -- one fuel pump only.
X-Type, S-Type Normally Aspirated and XJ NA -- Fuel Pump RH, Jet Pump LH
[Jet pump sends fuel from LH to RH side to be available to Electric pump]
S-Type Supercharged and XJ Supercharged -- 2 Fuel Pumps, RH & LH
[Pumps are in parallel and run together, all the time] **that is parallel FUEL LINE not ELECTRICALLY parallel.

I think it would help some to seek out the Fuel Trim FAQ and read the two papers. In this case, with the car running so bad under load, the fuel trims are only responding to the misfires. Misfires flood the exhaust with oxygen that didn't get burned and the trims go haywire. Consequently, they seem to indicate air leaks.

The misfire cause should probably be the central issue. Just based on the original description I tend to come down on the plugged catalyst possibility. You have to consider the 'self preservation' functions designed into these systems, and consider the ECM may be shutting down the pump or pumps to prevent a catalyst meltdown.

That may not be the case, but by the same token, catalyst substitution may be the only conclusive diagnostic strategy, one way or the other.

My two cents.......

 

fuel system duty cycle shutdown confirmed with a vantage pro lab scope both from ECM to rear modules and rear modules to pumps