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[dieseld4]

Hi I have a 3.2 when taking over the rpm's will surge up to about 2000rpm and back down to normal about every 5 seconds or so, I've changed the throttle bodies and it didn't help, there is no fault codes.

Has anyone any ideas what the problem is? 

[2woody]

what do you mean by "taking over" ? is that when overtaking something ?

[RobG]

Assuming you mean "ticking" over, check for vac leaks

[dieseld4]

Yeah I mean ticking over, I'll check for vac leaks tomorrow.

Thanks for your help

[24_Valve]

I don't know if you have an Idle Control Valve on the deisel?  Someone please correct me if you don't. But if you do, then remove it from it's rubber housing (1 x jubilee clip at front & unplug electrical connector at rear) Clean it with loads of carb cleaner & replace

[aaronjb]

I don't know if you have an Idle Control Valve on the deisel?  Someone please correct me if you don't. But if you do, then remove it from it's rubber housing (1 x jubilee clip at front & unplug electrical connector at rear) Clean it with loads of carb cleaner & replace

Not on a diesel no, but in his original post he says "I have a 3.2" which would mean DBW and as far as I know, no idle control valve (the ECU just moves the throttle butterflies to control the idle)..

[Kevin Wood]

Sounds to me like the engine is accelerating due to an air leak or similar until it hist 2,000 RPM where the ECU realises that it's uncommanded and cuts fuel.

Look for air leaks, as said. It would also be worth taking the throttle body off and giving it a good clean, IMHO, in case it's sticking.

Also worth doing a pedal test to see if there are any codes stored.

Kevin

[Jimbob]

this the same car with the TC light on after the gearbox change?

The ABS ECU config does have a bearing on Idle..
I had a blank config on mine which caused bad idle and stalling, the correct program fixed these issues 

[377]

this the same car with the TC light on after the gearbox change?

The ABS ECU config does have a bearing on Idle..
I had a blank config on mine which caused bad idle and stalling, the correct program fixed these issues 

[hijack]
Is this true on a TD ??
[/hijack]

[24_Valve]

Posted by: aaronjb Posted on: Today at 09:38
24_Valve wrote Today at 01:37:

I don't know if you have an Idle Control Valve on the deisel?  Someone please correct me if you don't. But if you do, then remove it from it's rubber housing (1 x jubilee clip at front & unplug electrical connector at rear) Clean it with loads of carb cleaner & replace 

Not on a diesel no, but in his original post he says "I have a 3.2" which would mean DBW and as far as I know, no idle control valve (the ECU just moves the throttle butterflies to control the idle)..
 

My mistake was looking at model stated beneath avatar and hazarding a guess... should have read OP properly, Anyway haven't a clue what DBW means so I'll leave to the experts 

[Osprey]

I'm no expert but DBW is Drive By Wire - no throttle cable.  So, as all throttle movements are controlled by the ECU anyway, there is no need for a separate idle control valve. 

[24_Valve]

thanks Osprey didn't know such things existed... never seen a car without a throttle cable 

[dieseld4]

Problem sorted, car was converted to gas but it was switch off, one of the little pipes which injects gas into the inlet manifold had split and the car was drawing air through it.

Thanks alot everyone for your help!