300 Tdi Auto (145k) Low Speed - Misfire? Hunting?

**auf_wiedersehen_pet** · 16th December 2011, 04:22 AM

Hi All,

Since purchase in 2006 my ultra reliable Disco as been a dream to own. Then in September it wouldn’t start. The AA (breakdown) fixed my "exciter wire" but two days later it conked again. A new starter was fitted and two days later it conked yet again. It appears the new starter was duff and this was swapped at the supplier’s expense. That’s when the fun started.

As soon as I started to drive it away from the garage something didn't feel right. At car park speeds (1,000 rpm) it felt "stuttery" as if the revs were on/off/on erratically. On the road, it pulled and ran fine apart from the 1,000rpm mark (typically 25+ kph, whiff of throttle to keep it moving in traffic) when it feels like a misfire/stutter/hunt.

It went back to the garage and after weeks of tests it was pinpointed to a STC 1734 throttle potentiometer. The prices in the UK were extreme so I purchased one from Les Richmond in Melbourne which cost £800 (Aus $1250) with delivery, insurance and customs fees. After several weeks it arrived in the UK and was fitted to the Disco.

All was well until last week when the symptoms arrived again. At low speed it misfires/stutters/hunts badly. It literally feels like its firing every 2nd/3rd revolution as it lurches through car parks. I also feel that it is running rough at most of the rev range but this could be paranoia!!!

I’d love to know your thoughts. What would you guys do? I can’t replace the throttle potentiometer every six weeks at $1250.

Could there be an underlying problem not caused by the throttle pot which “went away” for a few weeks to confuse me?

Could the pot be faulty after 1k? It did arrive in a LR box dated 2004 which is very naughty!

Additional info.
ECU chipped last December for $800
Kenlowe Fan
K&N Filter
Silicone Hoses
Gas Flowed Intercooler

Any suggestions would be welcomed as we have snow on the way and it looks like I’m going to be on the bus :{

**loanrangie** · 16th December 2011, 09:27 AM

Well for starters there is no ecu or potentiometer on a tdi so you have a V8 not a diesel ? The rest of your post reads as BS so are you just trolling ?

**nice1guv** · 16th December 2011, 09:44 AM

Maybe you have an EDC 300Tdi, but that seems a bit odd as you wouldn't be getting a potentiometer from Oz as we didn't have EDC 300Tdi's (unless it's the same part as a Td5).

**Psimpson7** · 16th December 2011, 09:50 AM

(in the uk at least) The 96 onwards 300tdi autos were edc and had an ecu and fly by wire so the post is probably accurate. agree that is seems strange that (it would be cheaper) sourcing one here as they apprently werent supplied here.

td5 throttle is about 90pounds from a dealer in the Uk so thats not the same part

p.s unfortunately I know nothing about them but hopefully someone will have some suggestions soon

**Blknight.aus** · 16th December 2011, 10:50 AM

you can source the throttle pot for what I call the eTDI300 here, just like you can source all the other non aus stuff here.

change the fuel filter, dismantle the fuel lines and blow them all back to tank or out.

pull the fuel cut solenoid and check it for contamination or any signs of metal particualte in the hole or on the needle.

you may also have the lift pump pushing air into the injector pump which means that you are potentially not far away from having a total failure to procede if the air leak gets worse and in a worst case scenario you may also wind up with a runaway engine if it leaks into the sump through the diaphragm.

**loanrangie** · 16th December 2011, 03:08 PM

Even if its was an EDC TDI you wouldnt be chipping the ecu or paying $1250 for a pot, hence why i say this is a troll.

**Blknight.aus** · 16th December 2011, 03:26 PM

of more importance....

since when is it cheaper to take a part from AUS to the UK than it is to purchase it locally and if it was a 2004 labeled box then it'd probably be a td5 throttle pot.

this could be entertaining to follow along with OR..

(dramatic pause, turn to face the camera que sudden revelation movie music here)

Has AULRO surpassed the UK forums for landy knowledge and google placement?

**Psimpson7** · 16th December 2011, 04:12 PM

Its definetely not a td5 part.

this is what the number points too

STC1734 SPEED TRANSDUCER AUTO TRANSMISSION | Discovery 1 1989-1998: Electrical | shop | www.lrseries.com | L. R. Series

**Blknight.aus** · 16th December 2011, 04:21 PM

have you tried a google for his profile name?

Auf Wiedersehen, Pet - Wikipedia, the free encyclopedia

**Discomark** · 16th December 2011, 04:41 PM

Originally Posted by Blknight.aus

have you tried a google for his profile name?

Auf Wiedersehen, Pet - Wikipedia, the free encyclopedia

Great show, watched em all years ago and just bought the DVD from Amazon so I can watch em all again. Difficult to follow if you can't understand a strong Geordie accent though (Jimmy Nail)

BTW, Heres a pic of Auf Weids rig, looks like a D1 with a Saudi grille!

http://i244.photobucket.com/albums/g...ights/kmn1.jpg

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