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        General >> Problems >> lumpy tickover
        
(Message started by: david49uk on May 25^th, 2008, 12:39am)

Title: lumpy tickover
Post by david49uk on May 25^th, 2008, 12:39am

Hi its me again had my 2.3 for about 3months now and its allways had a lumpy tickover.you come to a junction the tick over is fine stay more than 2mins seems like somthing turns off and tick over is bad but when you pull away its nice and smooth. I have tried most things cleaned air control, cleaned maff. cleaned air intake throtle its rather anoying, dave

Title: Re: lumpy tickover
Post by jonnycab on May 25^th, 2008, 1:57am

Idle air control valve may have a fault that cleaning may not have cured :-/

Title: Re: lumpy tickover
Post by david49uk on May 25^th, 2008, 2:01am

true ??? do u know where the egr valve is read a posting were they took the pipe of this and it cured problem.

Title: Re: lumpy tickover
Post by jonnycab on May 25^th, 2008, 2:30am

EGR valve is to the right of the engine at the back. They can sometimes cause problems which can be rectified by blocking off the small diameter vacuum pipe that joins to the top of the EGR.

Pull off the pipe & block it with a screw etc & see if there is any difference :)

Title: Re: lumpy tickover
Post by david49uk on May 26^th, 2008, 3:57pm

TRIED THAT NO DIFFERANCE ANY MORE IDEARS. DAVE

Title: Re: lumpy tickover
Post by v4-max aka Cheekyboy1 on May 26^th, 2008, 4:17pm

have you checked the hoses have no leaks? took mine off to clean maf didnt put the hose back on properly, car ran like you described.

Title: Re: lumpy tickover
Post by TiberiuS on May 26^th, 2008, 6:27pm

Unlit blowtorch will do a good job of tracing air inlet leaks, pointed around various gaskets and hoses you'll hear the engine smooth out and revs rise if it finds an entry point.

Usual disclaimer about blowing yourself up over what that bloke Tib on the car forum said etc ::)

Is the car driving ok at speed? Any loss of power? Throttle position sensor comes to mind as possible, sounds likely an unmetered air issue though.

Regards, Bruce.

Title: Re: lumpy tickover
Post by david49uk on May 26^th, 2008, 11:30pm

cars drives well at speed no loss of power its like .... of a shufle only when u sit for acouple of mins at a junction seems like somthing switches off then thats it lumpy tick over .I have been over it with a fine tooth comb since i have had the car shame realy because other wise it dose drive well.dave

Title: Re: lumpy tickover
Post by keitho on May 29^th, 2008, 6:53am

Could be that the O2 sensor is faulty and not switching. You will need an OBD lead to check this but you could just disconnect the sensor and see if it gets any worse. The PCM is very good at compensating when the oxygen sensors fail but it will show up as engine hunting at idle. The 2.3 has a single pre cat sensor which is clearly visible on the exhaust downpipe and connects with a multiplug.
See the articles on OBD and oxygen sensors for more inforation.

Title: Re: lumpy tickover
Post by david49uk on Jun 1^st, 2008, 1:37am

disconected the sensor no diferance is thatgoodor bad.?

Title: Re: lumpy tickover
Post by jonnycab on Jun 1^st, 2008, 2:35am

Sticking a bottle of STP, Wynns etc injector cleaner in the tank wouldn't do any harm :)

It may sort the problem, you never know. For a fiver it's worth a shot :)

Title: Re: lumpy tickover
Post by keitho on Jun 3^rd, 2008, 8:43am

If you disconnected the sensor and it made no difference then it is probably at fault.
You will need to confirm it really with an OBD scan.
The fault codes will tell you if the heater circuit is Ok and if the sensor is switching. You can graph the results in realtime and see the actual sensor switching. Eric R has written a lot on this and it's worth reading.

Title: Re: lumpy tickover
Post by david49uk on Jun 6^th, 2008, 1:53am

cheers for that were do i find eric r .

Title: Re: lumpy tickover
Post by Simmo on Jun 6^th, 2008, 5:54am

Eric R is a founder member of this site but is no longer involved with it. :(. The articles Keith refers to are all on the site. Click on FORD SCORPIO at the top of this page to return to the front page. Scroll down and in the 'Search' box at the foot of the page enter a subject ie: Maf, Obd, Egr and go through the various and numerous articles you will find.

Title: Re: lumpy tickover
Post by TiberiuS on Jun 6^th, 2008, 11:22am

If disconnecting it made no difference, I'd expect the sensor to be ok...when a sensor is unplugged, the ECU defaults to its own values so if the sensor is bad, it'd improve (or go into open loop running in this case, i.e ignoring both lambdas). If it also happens when the engine is cold the lambdas wouldn't be online anyway so wouldn't be the cause.

Could still be a lambda from your fault, usually though the trend seems to be that the Scorps tend to go rich when the lambdas die, from your symptoms you're going lean, hence my advice above about checking for inlet air leaks before you start spending money on lambdas.

Jon made a good point about fuel system cleaner, sometimes an injector pintle can get sticky (mine had this problem when left standing a few days). At times where the injector is only opening briefly (like at idle), it can stick and not open at all, causing a lean miss on that cylinder.

Title: Re: lumpy tickover
Post by david49uk on Jun 7^th, 2008, 2:05am

Hi used the injector cleaner made no differance idle is perfect for a few mins at a junction or standing then it is as if somthing swicthes off then bad idle some times takes longer to happen some times shorter,

Title: Re: lumpy tickover
Post by scorpio_man on Jun 7^th, 2008, 10:21am

hi there

could a seizing air con pump. :-/

see the replies to your mpg post.

hth

Title: Re: lumpy tickover
Post by david49uk on Jun 10^th, 2008, 2:21am

Hi there wasnt a aircon pump on the car when i got it .dave

Title: Re: lumpy tickover
Post by TiberiuS on Jun 10^th, 2008, 10:32am

Did you try looking for inlet air leaks? That's how it sounds to me.

So no aircon fitted then? That rules out that side of things.

Title: Re: lumpy tickover
Post by Jonnycab on Jun 11^th, 2008, 12:33am

Going back to idle control valve........cleaning it won't make any difference if it is the solenoid part of it that is at fault.

So if it is the solenoid that is sticking, then this may produce the symptom that you are having :)

HTH