I've just picked up a 98 tdi Discovery and am pretty new to the whole diesel thing - where are the spark plugs??? :rolleyes:

Seriously though, at idle it kinda surges. The revs rise up and down about 100rpm and strangely I've noticed that one of the interior lights (on an aftermarket cruise control switch) also brightens and dims in time with the surging.

As the vehicle is under a statutory warranty i want to identify any issues now and get them sorted out before this runs out.

Not really sure where to start looking, whether its electrical or mechanical. I'm hoping not electrical coz i bought a tdi to stay as far away as possible from the prince of darkness.

TIA.

Can't help you with the surging, but AFAIK Tdi Discos have ECU's, while Defenders don't.

Have fun with the Prince!


'

No ECU in mine, I had heard that late tdi's had ECU's but I'm pretty sure mine doesn't (there is nothing under the drivers seat where they usually are).

Sounds like a fuel supply problem. Bad lift pump and/or blockage in the supply line. I would check/replace filters as well.

JP

Australian TDi's never had ECU or EGR fitted.

Not even automatics?
Is it an auto?

T

I agree with Pendy.... Supply problem. Prolly lift pump.

The increasing/decreasing brightness of the lamps is probably just the change in output of your alternator at the mentioned changes in the rpms.

Billster

Sounds like a fuel supply problem. Bad lift pump and/or lockage in the supply line. I would check/replace filters as well.

JP

That year model Tdi should have only had some electronics (ECU) to control the EGR. My Tdi came out of the same year model Disco and was quickly converted to 1 wire operation.

Billster

That year model Tdi should have only had some electronics (ECU) to control the EGR. My Tdi came out of the same year model Disco and was quickly converted to 1 wire operation.

Billster

As stated by John, no Australian Tdi's ever had ECU's or EGR. Not even the last model (99/00) automatic discos. It just wasn't required for emissions so fortunately we didn't get it. The Td5 of course was a different story.

I've had a bit of a chance to drive it lately and its not something that happens all the time. It is idling in neutral about 750rpm but when it is playing up it idles at between 600-650rpm. Is this still consistent with the lift pump?
Also, does anyone know of the CAV type fuel filter with an inbuilt lift pump? This was mentioned on another forum but no one could recall any specifics.

I've had a bit of a chance to drive it lately and its not something that happens all the time. It is idling in neutral about 750rpm but when it is playing up it idles at between 600-650rpm. Is this still consistent with the lift pump?
Also, does anyone know of the CAV type fuel filter with an inbuilt lift pump? This was mentioned on another forum but no one could recall any specifics.

Everyone I know who has had a lift pump fail on their Tdi has noticed a drop in power going up hills, but I don't recall any mention of rough idling. Try and find a really steep hill and drive up to see what the performance is like - even better if you can get someone else with a Tdi to drive in front flat out.

how many miles are on it? Cold be the injectors too... Maybe some crud in them. Def. check or replace the pump and filters like stated previously

I've had a bit of a chance to drive it lately and its not something that happens all the time. It is idling in neutral about 750rpm but when it is playing up it idles at between 600-650rpm. Is this still consistent with the lift pump?
Also, does anyone know of the CAV type fuel filter with an inbuilt lift pump? This was mentioned on another forum but no one could recall any specifics.

Do you have a MD crawler box fitted to a LT 230 transfer case? What is the story on that?

JP

Do you have a MD crawler box fitted to a LT 230 transfer case? What is the story on that?

JP

He means the MD 30% lower low range gears. $1700ish AUD.

again dunno much bout rover TDIs yet, but i've done some work on Volkswagens and this is pretty common..

Vdub surging is usually fluctuation in the turbo boost, cuz the hose to the turbo wastegate gets all full of crap and residue. usually from crankcase vents. then again VW tdis have ECUs obviously, so it usually has to do with the mapping being screwy. but maybe there's some congruity there..

frankrover mentioned the EGR, but then IsuzuRover said it didnt have one. I dunno but again on VWs (sorry :( ) the EGR solenoid valve gets dirty and sticks....might make sense under acceleration, but not really at an idle. so basically i got nuthin :rolleyes: stupid newbs

felix