Frontera diesel low idle + stall problem

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Wed 19 Oct 2005 10:57
Frontera diesel low idle + stall problem - matstro
Got a 1999 Frontera Diesel 2.2DTI Manual with an idle problem.

It starts fine and drives well until I sit at some lights etc and let the engine idle. After about 5 seconds idling, the idle drops by 100 - 150 rpm and the engine runs lumpy. Drive away, and the engine isn't pulling as well (very subtle differnece) as before the car stopped.

Somethings kicking in and making the idle drop and then the engine isn't pulling quite as well as before that happened. On stopping the engine and restarting, its all ok until you stop and idle again.

If you idle the engine for 10 minutes, usually but not everytime, the idle gets progressively lower until the engine shudders to a stop altogether and stalls. When this stalling occurs, theres quite a bit of black smoke coming from the exhaust.

The cars been to 2 top notch injection places and a garage run by ex VX tecs. All the usual tests have been done and everyones scratching their heads. People are starting to say maybe its not a fuel supply problem.

Just to emphasise here - there are no day to day starting problems with the vehicle.

Pleeeeeeeeese can someone help as we're at our wits end with the only scenario sell it with a hidden or known fault or pay a blank cheque to an injection place who will guarentee to diagnose but it might take 10 hours plus @ £42 per hour then plus the parts to fix.

The injection guy says its unlikely to be the injection pump and it may ben more mechanical.
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Wed 19 Oct 2005 13:44
Frontera diesel low idle + stall problem - Number_Cruncher
As a cheap idea, check all the main battery and earth connections, making sure that really good electrical connection is made.

Also check the battery voltage is not too high - i.e., being overcharged by the alternator. The idle speed is a function of battery voltage on this engine. If the battery voltage drops, the idle speed is picked up to help recharge it; and vice versa.

Number_Cruncher
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Wed 19 Oct 2005 18:27
Frontera diesel low idle + stall problem - matstro
thanks Cruncher. Thats an interesting answer and I'll get it checked out.

Anyone else with anything else??

Having posted this query elsewhere, so far I've had two people crop up with seemingly the same problem on a BMW and a V6 Trooper so hopefully this is a general fault and not something unique to the Frontera - well I can but hope!
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Thu 20 Oct 2005 20:09
Frontera diesel low idle + stall problem - matstro
I've acheived a temporary fix by packing up the throttle pedal slightly. The pedal works a throttle potenionometer under the dash at the top of the pedal on the bulkhead.

Do these potentionometers wear out and if so, what are the symptoms and does any malfunction affect the idle speed. Its a Bosch unit.
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