No power below 2000rpm

I have recently swapped a reliable 1993 Frontera for a Freelander TD4 SE (2003) and currently I'm wondering why.

From cold it starts fine but struggles to rev at all for a few minutes. If you can coax it to 2000rpm it makes a lunge for the horizon. Once it warms up (slowly) it seems a little better but still very flat below 2000rpm. Once it gets really warm (gauge needle is vertical) you can sense a hesitation at around 2000rpm if you are cruising and occasionally it seems to slip into some kind of power limited 'limp home' mode. It starts fine hot or cold. Above 2000 rpm it seems quite frisky.

Engine light does not come on, no OBD codes, new Bosch MAF sensor fitted, cleaned the EGR, tried with EGR vac disconnected (and plugged), cleaned out PCV filter, cleaned out MAP sensor and inlet manifold (quite gungy in there). Any advice or help greatly appreciated. It has 90,000 on the clock. No signs of smoke. When it works its a good car but at the moment its not nice. By the way I suspect it was used for short school runs before I got it. Oh yes, there is a buzzing resonant noise from under the bonnet in the 2-3000rpm region that sounds like a loose heatshield or something(?)

Pete

Injectors? Try putting Millets Diesel Injector cleaner through - don't try others - Millets from Halfords - £12 something. If that does not work get an injector leak back test done when engine is hot.

angeloc said:

Injectors? Try putting Millets Diesel Injector cleaner through - don't try others - Millets from Halfords - £12 something. If that does not work get an injector leak back test done when engine is hot.

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I think the stuff you need is called Millers.

S. :hippie:

Yep, just checked Halfords website and decided it was Millers. Thanks for the advice, I'll give it a try.

Yes Millers works even better than Millets !!!! Ha ha me and my typo ridden phone!

i'd strart by checking the fuel rail sensor connection (unplug, check and clean the contacts) then i'd unplug the maf sensor to see if theres any difference....

And as for buzzes under the bonnet etc, get used to em, my bugger has three that I can't find, the latest and most annoying seems to be coming from the passenger footwell heater box, starts at about 15-1600 rpm and stops within about 500 rpm of these revs, bloody annoying.

Looks like I may have fixed this problem. Tried cleaning the MAP sensor, the EGR, new PCV filter, lift pump tested, new fuel filter etc etc. Checked operation of turbo solenoid. Tried a double dose of Millers. After the garage also admitted they were mystified and in desparation I disconnected the brand new Bosch MAF sensor and hey presto it would pick up at low revs. It now has an Italian Cambiare pattern sensor (with temp sensor) fitted. Power is now smoothly available from idle and driving is a pleasure. I have remembered why I bought it in the first place.

Two puzzles, why the hell was the new bosch sensor no good and why, when I disconnected the sensor, didn't I get a warning light? The lights are working, they both come on during the bulb check.

Anyway, hope this info is of some use to somebody, never assume a new part is any good.

Pete

Hi,

Can I ask what the Italian Maf replacement is?

is it direct replacement for the bosch one, and is it cheaper?

Thanks

As for the new Bosch Maf there are many Chinese copies even with genuine looking packaging that are known to be rubbish.

No malfunction light triggered for faulty Maf unless it has automatic transmission.

Vertuas said:

Hi,

Can I ask what the Italian Maf replacement is?

is it direct replacement for the bosch one, and is it cheaper?

Thanks

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The sensor is from a company called Cambiare. if you google them they come up as a maker of auto electronic components who appear to be Italian. They supply a sensor on its own (without the tube) and I paid about eighty quid. It includes a temp sensor so it directly replaces the bosch one. The appearance of the sensor is subtly different to the bosch one, theairflow sensor itself looks more robust for one thing. Anyway it was working well this morning.