I have a 2015 Ftype R with 22000 miles on the clock.Usually it runs great but sometimes on a "cold start" it runs really rough for around 4 -5 minutes after which it smooths out and runs perfectly. When I say "rough", I mean the whole car shakes and sometimes the engine stalls if I put it in drive.
'The car will always run smooth when its on fast idle but when the idle drops to 600 rpm is when it will get very rough and usually it will throw 'mis fire' codes P0300, P0301, and P305. This has happened after sitting for just one day and/or sitting for days.

The car has a new battery which is on a tender all the times, the plugs are new, Bank1 O2 sensors 2 and 3 have been replaced because they were "slow' and the injectors have been bench cleaned, None of which has effected this problem.

Any ideas?

 

There are many things that could cause rough cold running. The fact that it gets better as the engine warms up could mean vacuum hose leaks, faulty thermister in the coolant temp sensor and I think air intake has a sensor also well. Spark plug leads can also deteriorate over time.

also, sounds like your car doesn’t get much use given the low mileage. That’s probably the main culprit. 😀

 

Does anyone know if a symptom of injector failure is misfires? Because dirty injectors is one of the common issues on the AJ engines, and perhaps that is causing cylinders to misfire.

 

The OP did say his injectors had been bench cleaned. But maybe a couple are faulty?

 

Yes the injectors were bench cleaned and the car was the same after as before.

Are there typical places/hoses where this engine gets vacuum leaks?? Any plastic "pipes' with a crack that may seal itself when engine is warm on the intake after the MAF that could be causing this? How does one plug in a vacuum gauge on this motor? Can the temperature being reported by the MAF and/or the coolant temperature sensors be read through the OBD port so I can check to make sure they do not have off readings?

 

1. Smoke test .. rule out leaks
2. Clean MAF, change filters
3. Log PIDs.

If there is no vacuum leak, Probably something wrong with the low pressure fuel system.



Start car: high idle

Drops down to reg idle, pressure should read between 65 - 80psi, 79psi is most common.

If it is lower than 65 psi, either the low pressure pump or the sensor is bad.

• Check PID for the sensor. Normal range is 0.8V - 2.5v
• if the sensor is stuck 4+V then its shorted

 

Do you have a "good' spot to inject the smoke on the V8 version?

 

Pick your poison. Take the heat shield off to check the injectors that were cleaned

 

When yo say "check the injectors" do yo mean pull them and inspect them or ???

 

My F type R still has this problem. Please look at the video in this thread. The car starts this way about once in 8 cold starts and always takes about 5 minutes until its running correctly. .Its almost like something warms up during the 5 minutes, as it slowly getting smoother, until 5 minutes have past then its idling perfectly normal.

What could possibly be causing this?

 

Is the MIL on? If so, what codes are stored?

When the misfire(s) occur, does the MIL flash?

Has the engine ever been overheated?

Were the Teflon seals on the injector tips replaced and correctly sized prior to reinstalling the cleaned injectors?

 

My 2015 R fires up after weeks like a drove it the day before. Lucky I guess.

 

Mine has an occasional bit of weirdness after it's been sitting for a few days - I put my foot on the brake and press the starter button and everything lights up but the car doesn't fire, just sits in accessory mode. Next press of the starter fires up instantly. Doesn't always happen, though.

 

Twice I have had strange starting issues but without a misfire. Once on a cold start the rpm settled in a bounce at 1800-2000 rpm. It started with the usual quick high rpm but the started bouncing repeatedly in that rpm range. I shut it down, it restarted normally. About an hour later it did the same thing. I drove it the rest of the day with several stops and never had another issue. No warning lights.

 

I definitely want to see what happens with this thread, I feel like I have a much less critical version of this problem and it might develop into something similar to what the OP describes; my car starts right up but shakes intermittently when idle and not moving. It shudders every couple seconds, I can feel it mostly in the seat, not in the wheel. When the car warms up, the shuddering or shaking mostly disappears and the car only shakes very slightly every couple seconds, but it still shakes. I've got no CEL, nothing, it just doesn't quite feel normal. My fuel system is certainly clean, and my battery is fine. I've always imagined it's gotta be a tiny vacuum leak or dying sensor...

Keep us updated, I guess.

(2016 F-Type R AWD)

 

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There should be codes stored. A decent obd reader would be helpful. If that's a vacuum leak, my guess is that it wouldn't clean up the idle that quickly on a restart.

 

Maybe, maybe not.

Around the turn of the century, the EPA allowed cold-start misfires on vehicles to be ignored, because too many owners had CELs set for non-critical issues.

On other cars, this cold-misfire issue is often because of a too-wide spark plug gap. Too bad its such a PITA to remove & check the F's plugs.

 

I just noticed..when it's first started and misfiring, the Jaguar logo in the center screen flickers and the battery light is flickering on. Maybe it's an electrical issue. Voltage drop? Voltage loss? Is the battery light a result of the dropped rpms?

 

Corroded earth somewhere?

 

Or, loose connection?

Suspect is the large red battery cable going from the trunk (boot) to the engine bay (just to the right of the driveshaft).

Also, if the F has needed resets (battery disconnects) as a result of OBD II parasitic drains, it would be wise to look at those connections.