Technical Help please

[poco]

I'm having problems with an 07 plate 2.3 Ducato, it starts and runs fine for around 3-4 minutes until it starts to warm up then it starts hunting, it drives OK, no smoke, just hunting when stopping at traffic lights ect,
no error codes I'v changed the fuel filter, done a flow test on the injectors all OK, it had a replacement egr valve 30 000 miles ago and has had the throttle body replaced for the up graded one? any one got any idea's

 

[The Panda Nut]

hunting can be an air ingress into the fuel line.. Lots of places for ait to be drawn in. . Try loosening the fuel cap in case a vacuum is building in the tank and causing air to be drawn in. Check all fuel line connections are correctly tightened including both sode of thr filter. You can put vaseline toind each joint in turn to add temprary seal and see if this reveals anything. I have heard of air leaks in filter heads, hand primer bulbs and even from cracked injector pipes. Its a case of slowly and carefully checking each possible place in turn and hopefully you will find the cause. Was the engine OK before filter was changed?

 

[poco]

hunting can be an air ingress into the fuel line.. Lots of places for ait to be drawn in. . Try loosening the fuel cap in case a vacuum is building in the tank and causing air to be drawn in. Check all fuel line connections are correctly tightened including both sode of thr filter. You can put vaseline toind each joint in turn to add temprary seal and see if this reveals anything. I have heard of air leaks in filter heads, hand primer bulbs and even from cracked injector pipes. Its a case of slowly and carefully checking each possible place in turn and hopefully you will find the cause. Was the engine OK before filter was changed?

Thanks for your reply I changed the filter to try and solve the problem

 

[The Panda Nut]

Has a similar problem with a Citroen disel many years ago. That had a bulb fuel primer fitted. It had a pin hole in it and was sucking air which sent it haywire. I hope you find the cause. I think I used a BOSCH diesel service centre in the end and they located the problem pretty quickly. Good luck

 

[Communicator]

I have had a diesel engine stall due to air ingress via the buttonoperated, diaphragm priming pump incorporated in the fuel filter.
I inadvertantly cause the engine on on my 2.8jtd PVC to hunt when changing the step retraction to D+ initiation. Due to incorrect installation by the converter, a capacitor in parallel with the step relay, was being connected to D+ when the voltage increased. This reduced the alternator excitation and ouput voltage dropped. ECU sensed this and increased rpm, also capacitor charged up. Alternator output increased, and cycle repeated. Rather larming.

This experience leads me to suggest an electrical problem, as an alternative possible cause. Has the engine earth strap been replaced recently?