Idle issues 20SE engined carlton

[snowy70838]

The idle is very erratic on my 1989 20SE engine carlton.

It also effect driving at low revs, anything below 35mph, causing the car to judder around.

I have cleaned the idle control valve and replaced it for another second hand item but the problem still persists.

Also every now and again the engine managment light comes on and off. More so when really cold??

I have also checked the wiring to the idle control valve and found that a new connector has already been spliced into the loom just before the two wires enter the main loom.

Any ideas where i should be looking?

Thanks

[Murph]

I would check the airflow meter next.

[Neil]

If the engine management light comes on you might be able to read a fault code. Do a search on here for how to read the codes using a paperclip.
Something else that can play up and cause problems like this is the engine coolant temperature sensor.

[doz]

I'd say you've got a air leak.

[snowy70838]

No air leak, i have checked for this.

I have ordered a new coolant temp sensor.

I did buy an airflow meter off someone but it just puts the engine management light on all the time.

Does anyone on here have a good airflow meter i could buy??

The strange thing is that sometimes the car behaves perfectly for a few miles. Like today on the way home from work. It drove perfect for the last five miles in slow traffic.

The engine management light never comes on on the return journey from work. Only on the way when it is really cold. But it never stays on for more than four seconds.

Where is the diagnostic plug on the carlton?

Thanks

[Murph]

Its tucked up behind the drivers side suspension turret.

[snowy70838]

Thanks

[DevonGSi]

Id say coolant temp sensor, as you mentioned it was fine in slow traffic, so no airflow thru rad so running a bit warmer and masking the problem.

[snowy70838]

Sorry that was missleading. It is usually worse in slow traffic, or more noticable. It was fine yesterday. It is usually bad but somtimes, like yesterday, it is good.

[Jimmy]

im sure you've checked this too, but way aswell suggest plugs and leads?? this cold weather can effect the obvious. Have you got the right airflow sensor too ie: for a 20SE and not foe another sized engine if that would make a difference?... good luck with matey 

[snowy70838]

I have changed the fuel filter, rotor arm, dissy cap ( That was fun to get at) and ht leads.

The spark plugs look new as did the air filter.

Cans someone confirm what the part number should be of my airflow meter?

Thanks

[melinx]

You can check some of the issues mentioned by referring to the link below.

http://totalcarlton.com/forums/index.php/topic,9096.msg73701.html#msg73701

[snowy70838]

Right, i have done or changed;

Changed Dissy cap,
Changed rotor arm,
Changed Ht leads,
Checked spark plugs, as new
Checked air filter, as new
Changed idle control valve
Remade wiring to idle control valve
Changed coolant temperature sender
Changed oil trap in rocker cover

The problem still persists.

Anyone got a good airflow meter?

Thanks

[Dave the Builder]

I've got an afm for the se engine,but where are you ?
but have you tried the fuel pump relay and conections where the loom joins the pump on the fuel tank ? had similar problems my self with this.

[melinx]

I strongly suggest that you check the fault codes before you spend more money and time chasing the problem.

[snowy70838]

Thanks for the suggestion of the fuel pump relay. I will check this.

I will check the fault codes before spending any money.

Thanks

[melinx]

I concur also with Dave the Builders suggestion

http://totalcarlton.com/forums/index.php/topic,8820.msg70005.html#msg70005

I've had no problems since doing what I outlined in the above thread

[snowy70838]

I've got an afm for the se engine,but where are you ?
but have you tried the fuel pump relay and conections where the loom joins the pump on the fuel tank ? had similar problems my self with this.

I am in north wales, Prestatyn.

How much for the AFM? I wouldn't mind a spare as they seem hard to find for the SE engine.

Will be looking at the fuel pump relay tommorrow and checking the fault codes.

Thanks for the help.

[Dave the Builder]

I'll dig it out and check condition of the air flow meter,it was removed from my pre facelift and that never had engine management light issues,
the SE afm is diffrent to the later type (either has 1 more or 1 less terminal on the loom ,can't remember which).
but lets hope the fpr solves your problem.
if it don't ,and you want the afm then make me an offer and i'll find p & P cost 

[snowy70838]

I would like the afm even if the fpr fixes the issue as i would like to have spare.

How does £30 posted sound? Seems the going rate for similar items?

Thanks

[snowy70838]

I checked my fault codes this evening. The two codes i have are 12 and 48.

If i am right these mean;

12 Initiation of diagnosis.

48 Battery voltage, Low voltage

So have i got this right?

The car starts well, has no charging issues? Everything seems ok electrically??

Just checked the battery voltage without the engine running;

12.7Volts

Check with the engine running;

14.2Volts

The car produces 14.2 Volts at idle rising to a max of 14.7 Volts. I will try it again tomorrow when there is more light under electrical load.

Any ideas??

Thanks

[melinx]

Yes, you have it right; those voltages seem fine to me so I'm a bit puzzled about the fault code appearing

The only other test is check the battery voltage on cold starting and ensure that it does not drop below 11 volts !

It may be that you have a bad earth somewhere causing the ECU to see a low voltage due to the voltage drop across it

[Murph]

That would be my first port of call.
Check the earthing points on the cam housing by the injector rail and the one on the inner wing by the battery.

[snowy70838]

I have just had the battery tested, it is ok.

Could this cause the idle fault?

Thanks

[Murph]

An earthing fault could if the power to the ECU isnt as it should be.