97 300 TDI Auto cutting out randomly

Hello peoples, been a member her for quite some years and its been super useful, not many posts but ive usually had every question answered by searches but this time i'm lost. here goes:
Picked up another disco 1 300tdi auto the other day and it just died on me on the way home, it fired back up right away but then died again. I let it sit for a few mins and it started and drove for about 10 mins then died again on me. I got home eventually.

what i've done so far:
cleaned out sedimenter, was a tad mucky but nothing major.
fuel stop solenoid clicking and working
tried to bleed at fuel filter but was unable to get fuel to flow out even with cranking the engine over.
auto box seems to be over filled which i will sort tomorrow

another thing its done is when going uphill at about 3k rpm the power drops for a slip second like a misfire it has done this a couple of times.

I thought it might have been the spider but from what I've read it doesn't have one. It does have fly by wire which I assume makes it an EDC but it does not have the DDS box on the fuel pump, so may it have the spider box? (just asking before i rip the dash out)

I think that's everything up to now, Cheers in advance!

Sounds like fuel starvation, have you checked the fuel lines for perishing, pin holes and especially on top of the tank and the inlet/outlet from the sedimenter as it has been known for these to corrode right through.

Auto box, are you checking the fluid correctly?

I know it sounds silly but there is a procedure to checking this and not everyone knows it.

cheers for the reply. i did think fuel starvation but it seems to cut out immediately making me sway towards the pump solenoid cutting out. I checked the fluid today about an hour after a drive so it was still a tad warm. I used the proper procedure but ill check again when stone cold. when warm it was a good 4 inch higher than the marks though. I've not yet checked the unions at the sender unit yet and still not managed to get fuel out of the bleed screw at the filter.

Well the auto box was 1L over full, all is good with the level now and is changing smoothly. Could an auto box cause a cutting out issue of any kind in a 300tdi?

The EDC ECU will cut the power at 3000rpm if the wastegate is stuck shut to prevent overboosting. It's really noticable going uphill under load and feels as though it's trying to change gear but it isn't. This doesn't explain why it's cutting out but may be the reason for your loss of power going uphill.

When you say it cuts power, does that mean it wont go past 3k rpm? Mine gets to 3k then power drops but then it continues past 3k as normal. I'm planning on replacing the fuel lines from the sender and bypassing the sedimenter as well as installing a new fuel pump and fuel filter to eliminate air getting in if it is.

Do a search for the spider .. part of the security system which is known to be unreliable. There's a fairly cheap bypass available for it, or make your own!

Paul D said:

Do a search for the spider .. part of the security system which is known to be unreliable. There's a fairly cheap bypass available for it, or make your own!

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I may be wrong,, not uncommon..LOL, but I thought the auto did not have the spider....??

Cheers

neilly said:

I may be wrong,, not uncommon..LOL, but I thought the auto did not have the spider....??

Cheers

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Heheheh, I didn't know, obviously, which might be why noone's mentioned it ...

Thats another thing, i initially thought that with EDC the pump would have the DDS unit fitted but mine doesn't, so I'm not sure if it has the spider or not!

defenderdan86 said:

Thats another thing, i initially thought that with EDC the pump would have the DDS unit fitted but mine doesn't, so I'm not sure if it has the spider or not!

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You can rule out the fuel solenoid being your problem by simply doing a "hot wire" straight from the battery positive to the fuel solenoid.

defenderdan86 said:

When you say it cuts power, does that mean it wont go past 3k rpm? Mine gets to 3k then power drops but then it continues past 3k as normal. I'm planning on replacing the fuel lines from the sender and bypassing the sedimenter as well as installing a new fuel pump and fuel filter to eliminate air getting in if it is.

Click to expand...

If yours continues past 3000 rpm then it won't be the wastegate. Another cause could be broken or corroded tracks on the TPS on the pedal but this would cause a loss of power at a certain pedal position rather than a certain rpm.
Jap imported EDC models didn't have a spider fitted but not sure about UK models.

I've got some fuel hose coming and a new lift pump so ill replace the lines from the sender unit to the lift pump and see if that sorts it. If not ill wire a light up to the fuel solenoid so i can watch it on the road see if it cuts power. Ill let you know how i get on.

UPDATE. I've replaced the send and return fuel lines, also its had a lift pump (old one was dead) and a new sender unit (old one had lots of cracks) its stopped the stumble but it still died on me today, it seemed to be when decelarating quickly ish. only did it once on a 20 min journey. Am i right in thinking that auto boxes cant stall the engine? tomorrow ill look at the power feed to the fuel stop solenoid.

and now ive replaced the stop solenoid after it died again but this time it had a permanent 12v supply to the solenoid so the solenoid didnt shut off, the problem still exists. it seems to be worse when braking fairly hard it just dies but starts again right away. thoughts?

sooooo if anyones interested, It seems that after 2 changes of ATF (left the filter in) and a bottle of lucas transmission fix, it did not die today! gearbox behaved itself. The oil that came out the first time round was very dark but not burnt. I never would have thought that a autobox playing out could stall the engine but hey ho. fingers crossed thats it!

Thanks for the update, I'm also surprised that the autobox is the cause but fingers crossed that you've solved the problem.

Update no 2. The problem persists!!!! I've had a right time with this but i have a theory and would like opinions before i strip it down. So...I think the crank pulley has shifted on the woodruff key and is moving around. Under light driving the problem is less apparent, i noticed that the fuel pump has been advanced as far as it can be so this makes me think that as it has been cutting out only when braking hard that the reverse in force on the crank when slowing down quickly is shifting the crank pulley and placing the timing too far advance and causing it to stall, when restarting the engine in shifts it back to it normal position and all seems ok until i brake hard and it shifts the other way again. This is the last thing i can think of and to me it makes more sense than anything else....opinions?