UK RHD M2.7 348 Running like a B***h at low revs

Of course.... I should have guessed that... I guess I'll never be starring as a contestant on Wheel of Fortune any time soon.......

I'm thinking that particular word is blocked because of the possibility it could be used for bashing women --- which would not be acceptable. But, in the context of describing a car --- why not?

 

Perhaps one of your temp sensors has failed such that it only reports that the temperature is cold, whether it is cold or hot in reality.

 

Sounds like a candidate for the davehelms gold package!

 

And the crank sensors?????????????

 

Well.... if the operation temperature causes so much difference on behaviour, at least it's a good feedback to help diagnosis...

Personally I have had the experience with faulty ignition coils... and usually they fail when hot... if no extra coils are available to test, try to find some diferent shade on either bank's spark plugs.. and then switch them to confirm..

Other possibility is a sticky IACV valve. When cold it allows extra air to compensate the richer mixture, but if keeps open then, the the mixture gets too lean when the ECM's change the status to normal running temperature (or faulty temp sensor as mentioned before)

 

Well... it could even be a defective ECM....

Can't you at least tell by the feeling if the missfiring is due to fuel or ignition cut-offs? Usually the ignition cut-offs are much more harsher...

Colour of ignition saprk plugs are a good indicator also....

 

Have you considered going to a roling road diagnosis centre?

They will imediatly find out what is causing that, even under a very light load..

I believe that there are plenty in the UK.

I understand that you do not want to let your baby on stranger's hands for repairs, but this at least would point out the way to wich system is failing and wich components to change....

 

Hiya Dapper

If its a feeling of being too rich or over fueling it could be engine tempature sensor for the engine management telling lies and running too rich and confusing the lambda (oxygen) sensors, dont rule out fuel pressure too high for some reason, I dont know what exactly controls the fuel pressure on your car or sticking injector/s dribbling causing low speed flooding...?

Or is it possible the cam timing could have jumped on a cam during a start up after a long lay up you really need some live data from a diagnostic machine, and have a look at the maff readings etc. Read eobd with a fiat, lancia connector, should work but I believe you have to reverse the two outside wires on our uk cars?

Hope this helps

 

Could it be the thermostat?

If the cooling fluid does not flow, all temps are wrong on both sides of it... or at least diferente from the temp sensores and fan switchs....

 

I already mentioned ignition coils/modules ....

Regarding the erradic fans, it could indeed be some switch problems.... but could also be thermostat and/or air in the cooling system. Use the bleeders next to the RH hood hinge..

 

Indeed, they could be the gremlim you look for..

 

Best of luck...

It's a great sensation when one finally gets that weight off the shoulders...

 

Well took mine out today running rough just like yours seems to be
car drives great apart from very light throttle openings between 1500- 2800 rpms
and full throttle and if the engine is under any load ( going up hills etc) its fine.

ATM i am putting it down to crappy supermarket fuel so i will do a load more miles at the weekend..

As to your new coils i got some from ebay a while back fitted them to the car and found the same as you it ran worse! sort of felt a bit flat when under load so i sent them back.

Mine is going for its annual in a few weeks so i will let them service it road test it ans say what they see if the problem is still there, i do feel however that mine does run a bit rich i do have de-cat pipes on though!

 

You can check the gap between the rpm sensor and the pulley. I believe it should be 0,6mm (at least the Ferrari dealership chief mechanic said so).

You can also dry the conector and put some contact grease.

A detail I found on mine, when the sump protection was removed, were mice traces... so damaged wires can be a cause.....

 

1-4 bank code 4122 - cats too hot (strangely I didn't get any panel lamp warning whilst driving?)

5-8 bank code 1121 - RPM sensor.


1-4 bank code 4122 - cats too hot (residual code?)

5-8 ban code 4444 - no faults

From the above could it be that the 1-4 rpm sensor is faulty such that it isn't producing a fault code (even with a non running engine) but due to whatever fault it has, it causes that bank to run hot, hence the 4122 cats too hot code?

I would normally expect to get code 1121 from 'both' ECU's with a static engine.[/QUOTE]

By RPM sensor is that refuring to the camshaft sensor, if it is then your timing advance will be all over the place and running on limp home map I should have thought, cant really see how its telling lies but if it was showing the wrong advance it would make that bank run hot as well as setting the wrong ignition timing as the ecu looks at the cam and crank angle together to set firing order and inital timing setting?

If this is the case and with your fault codes I cant see why the engine management light isnt showing

With your intermittant fan operation could you have some kind of earth wiring problem somewhere as all the faults could be linked, Has there been any work done where a earth wire could have been left off or loose?

 

Your 5/8 bank ECU should not have cleared the 1121 code from simply starting the engine. The codes only get removed when power is cut to the ECU (or when more than 50 codes are stored it starts dropping the oldest ones).

Assuming you did not disconnect your battery and reset your ECU's before starting the car again, it appears power was cut to your ECU from some other means and cleared the memory. This could be a faulty relay or damage to the ECU wiring loom (for example check that the rubber grommet hasn't worn through in the engine firewall where your ECU wiring runs).

If your ECU is frequently resetting itself from a power out condition while driving that would give you a rough idle from the bank cutting in and out. I haven't read all the reponses in this thread, so you may have already tried (1) swapping relays for the ECU's to see if the "code clearing" moves to the other ECU or (2) swapping ECU's to see if the problem still remains on the same bank.

 

The RPM sensor code follows different rules. You'll always get it when checking codes with the motor off, but you'll never get it with the motor running unless there is an actual RPM sensor error!



*if his codes were cleared via a faulty cable or relay or fuse or via the battery disconnect, then his other error codes would have been cleared instead of remaining