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Discovery300TDI2023

New Member
Hello,

I've seen a few various threads around the internet concerning this particular issue, but I can't quite seem to figure it out based on the information available.

I have a 1997 300tdi auto disco, and around 1000rpm, the throttle cuts and the check engine light comes on. Otherwise performance is as normal. The throttle only cuts briefly around 1000rpm.

I've seen some people suggesting it could be a loose/ bad connector at the ECU, but I don't know which connector it would be. If someone could explain or show pictures that would be very helpful.

I've seen some people also suggest it could be the throttle position sensor, however i cannot find one anywhere on my engine, which is confusing as all 300tdi auto discos are EDC? Where would the TPS normally be mounted? Or would it be on the throttle pedal rather than in the engine bay?

I'd really appreciate any help anyone can offer, this problem is doing my head in!
 
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I had a similar issue a couple of years back following a timing belt change, I took it straight back to the mechanic and he immediately rectified the problem for me, it turned out the pump timing was very very slightly off, after it was re-adjusted to the correct position I never had a problem again, I think the edc system is quite sensitive to timing but when set up correctly it works very well, I'm sure a few people will probably tell you to throw it away and fit a manual pump but I wouldn't agree, after ten years of trouble free motoring I am very happy with mine, I know some people experience starting issues and some say they lack performance but I've never had any problems. Good luck with getting it sorted and don't forget to let us know how you get on.
 
The throttle postion sensor is mounted on the throttle pedal bracket where it fits on the footwell. A bit difficult to reach. A cable also goes from the pedel to the gearbox to give the kick down feature. The tps has a metal wiper that passes over a track to vary the electical resistance, and thereby tell the ECU how far the throttle should be opened. The track wears through, the ECU fails to get the signal and the engine drops back to tick over.
 
update: a new problem has developed. Now there is very poor acceleration pulling away from a standstill. Starting is also rough and lumpy. I have done the timing (only the basic method using pins) and fitted a new lift pump just in case this was at fault, but no luck.

I suspect I may need a new manifold gasket / head gasket so this will be my next point of call.

Due to this newly developed problem I'm inclined to suggest the tps is not at fault.
 
Update: i think the head is fine, changed the manifold gasket (old one was split in 2) but no luck. same starting issue and throttle cutout problem. Any ideas? Maybe some sort of air/fuel leak somewhere in the system?
 
If you have edc then its on number 4 fuel injector - so some sort of wire must be attached to the injector and might be worth a try and unplug it to see what happens

in africa we didn't get many or any of the edc 300 tdi's so am taking a guess here
 
Stand pipe steel pipes pin holed under boot floor
Ignore the edc bit and start with the simple stuff first
 
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