P38 Missing / spluttering / not running smoothly

[Haggis]

I have 2 p38s (1999 250,000Km & 2000 140,000Km) both have started to splutter / jolt when accelerating - any ideas on what the problem could be?

[rishilandguy]

Check spark plugs, ignition coils, plug wire if either of these need change, last to doubt is fuel pump as you said it splutter while accelerating only.

If car recently went to mechanic and since then started spluttering, then check the spark plug gap. If all good, then check spark plug firing order. Hope it helps.

[sohailrangi]

Both having same issue at same time, better change the mechanic or parts supplier.

[Ghassan]

Was your problem sorted out , as I have same symptoms with my Disco 1 1999 model and all started with a faulty Distributor , that I had changed with a used one , put on new Lucas Cap and New set of Original Cables . Changed the Spark Plugs, changed the MAF and the IAC Sensor, cleaned the throttle body, changed the fuel filter and the shrugging, spluttering, not running smoothly is there and some times it does accelerate and sometimes it doesn't cope !!! On neutral you can still hear the exhaust noise note very stable as it goes bhbhbbhbhbbbbbhbhbhbhbbbb like cough !!!

[Sharky]

Nobody has mentioned injectors yet, I had some issues a few years back with one of my Disco IIs and had to replace 3 injectors.

[tyro]

interesting.

[KimChance]

I realise this is an old post but in case anyone has a similar problem, misfiring under load with the Bosche equipped engines, particularly if it occurs around 2300 RPM, is almost always caused by the MAF (Mass Airflow Sensor) becoming dirty. The sensor can be cleaned using an electrical contact cleaner and there are specific aerosol products for MAF application. Cleaning will not necessarily provide a complete solution, but if you get any improvement at all you know you are on the right track. Replacement with a new genuine MAF sensor or at least a genuine Bosche unit will make your engine feel like a new one. They are not cheap but there is little or no labor cost as it is a simple job that almost anyone can do.

If the engine still feels unwilling your problem may well be the oxygen sensors which are in each of the exhaust pipes about 450mm from the manifolds, these are cheap to buy and to fit and make a significant difference to your fuel economy and performance. Try to get good diagnostics done first either through an authorised Landrover dealer or an authorised Bosche dealer, it isn't expensive and it can save you time and money chasing down complex problems, often resulting in the replacement of parts that were functioning perfectly well and were not a part of the problem at all.

We live in a very dusty environment and the liklihood of the MAF sensor becoming dirty is high.

[sohailrangi]

Thanks Kim, for sharing such an important finding. You definitely look an old LR fan and have many years of either LR owning experience or DIY experience or both under your belt. Welcome aboard.