How slow 300tdi auto

Well I finely got to the bottom of my cold start problem (wires down the back of the head melted ) now the problem is my 300tdi is totaly gutless
before I fixed the starting problem once stared it went like a train and would pull a house down ( towed an artic up a hill in the snow) and would accelerate like a sports car (allmost )
During the fault finding It had a timing belt kit on and an injection pump ( back to the original pump now which I know was ok once started ),
I've checked the timing 3 times now an it's spot on ,flywheel locked ,pump pin slots in easy ,camshaft lined up so all fine there ,tried adjusting the pump timing either way but no differance so reset it back to line pins up , valve clearances checked ,injectors checked ok still the same ones as before ,
I think with the wire melted together the ecu would have being putting more fuel in (engine coolant temp sensor and turbo boost temp sensor wires with faults) but it is now so slow its dangerous ,I travel on the A1 past washington sevices on a morning and it will only do 40mph so I have to pull off and go through the back roads to work which adds about 15 mins to my journey
I also tried putting a adjustable resistor onto the coolant temp sensor wires but that didn't seem to help
Does anyone live in the chester le street area with an auto who could compare it with theres for me and can anyone recomend a garage in the area who could have a look at it for me as after this long I'm about to give up

Tricky one,dont envy you at all.I have 2 with EDC and all the fun it entails.Have you checked to see if any oil has wicked through the loom back to the ECU box in the drivers kick panel? Another fave is heat damage to other wires insulation in the loom transmitted by the heat affected sensor wires.Maybe some continuity checking at the multiplug?

I would give some thought,once you have got around this,god willing,to putting the two sets of sensor wires in some woven heatproof tube.

I wish I had something more constructive for you....sorry !

Its starting to sound horribly like new pedal and manual pump time,might be the cheaper alternative,sadly.Its a real shame that the EDC is so fraught with problems,the system is great on the rare occassions that it works.BigLad is a good source on EDC stuff..........

thanks shocker I've had the ecu out about 1/2 dozen times to check the multiplug pin info and no sign of oil or moisture even split the harness open and opened the plug to check inside
One thing I'm not sure of is the reading for the air temp sensor in the air flow meter pin 13 and 52 I think or the reading at the meter pin 1 and 4
Checked out the air flow meter and had 5 volts in and when operating had between 1.5 and 4.8 coming out so that bit seems ok
I'm going to ring a couple of places tomorrow and see if they have the equipment to monitor live data and read the ecu
I had a guy out a few weeks ago who used a autodiag tool which was great but he said every thing electrical seemed ok then I found the melted wires so at £35 not sure if it's worthing getting him back ,in his defence he said he specilized in petrol engines

0-60=Boil the kettle

forgot to mention after a weekend fitting swivel seals and bearings ,front springs and shocks ,front brake discs and pads and a couple of brake pipes ,a couple of temperary patches to rear arches it passed its mot today (couple of advisorys ) finished at 23.30 last night
now if only I can sort out the power
may look into manual pump conversion but i've spent so much time now would realy like to sort out the edc system
If only I could borrow a few bits to try before I end up spending

When I bought an EDC box on ebay I paid about 40 quid.But the problem you have doesnt make any sense,does it?Defies logic.Why did it run OK before? I can only think of other issues like lift pump (they fail at the drop of the proverbial) or fuelling probs,air in the system,filter seals,banjo washers (worth replacing or annealling) ,things of that nature.You havent had the head off or injectors ou....have you?You would have said,Im sure.I say that as I had a power loss due to poorly seated injectors before,bad washers.Since the pump has been off there could be fuel/air issues.Of course the sedimentor is a favourite for power loss.Or turbo hose delam.Clutching at straws,I know ! All of these would be a horrible coincidence....but in my experience it happens that way.

Have you looked at (ahem) a certain other forum?Theres a link to the thing about the coolant temp sensor that you could use to find related posts......

Land Rover UK Forums

Blagged from another thread so I cant take the credit.....two more ideas :

blocked catalyser.....are you de-cat? I have had two vehicles now suffer from this,a volvo that lost power and a scorpio that wouldnt run at all - try dropping the exhaust manifold,just free it off on the studs.

fuel return line......blow it through.

...mate,Im at the other end of the country,if I could help,I would.Best of luck and stay in touch !

shocksi

There is nothing wrong - AT ALL with the Bosch EDC system,its too reliable which is why no one knows what to do when it goes wrong.From what you say the first thing I would do is to get it on Testbook and see what the ecu is seeing from the coolant temp sensor.It has a feature built in to seriously limit power output if it overheats,same as the p38 diesels will do when the crap BMW water pumps fall apart.So if the ecu thinks its too hot you get no power - sounds very much like your problem.

have you tried running it with the MAF senser disconected the maf's do go faulty i would also try dropping the exhaust at the manifold or removing the cat you dont need it for the mot on a diesel ps mines a edc as well but goes like a train just had a new head and a bit of TLC i bought it as spares with 12 months test and head gone

eightinavee said:

There is nothing wrong - AT ALL with the Bosch EDC system,its too reliable which is why no one knows what to do when it goes wrong.From what you say the first thing I would do is to get it on Testbook and see what the ecu is seeing from the coolant temp sensor.It has a feature built in to seriously limit power output if it overheats,same as the p38 diesels will do when the crap BMW water pumps fall apart.So if the ecu thinks its too hot you get no power - sounds very much like your problem.

Click to expand...

mine has 3 sensers 1 on top of the head near 2and 3 cylinders (think thats for EGR) 1 under the themostat (for temp gauge ) one on top hose (for air-con fans ) and a blank next to it some have another senser in the blank

too many wires

Its the one in the top of the head that gives coolant temp to the EDC ecu,cant remember any values for it - I have them at work.You need to measure them at the ecu plug to be sure thats what its seeing if you cant get it on Testbook.I'd be suprised if that isnt what the problem is.

thanks guys
egr & cat removed and single box exhaust system fitted as soon as I got it back in november,
tried the maf sensor and its getting 5volts and when operating it varies output between 1.6 & 4.8 also tried running it without it connected
I've booked it into teamvalley landrover on wednesday to get it checked out £65+vat
About to give up as I have no means of reading the ecu (equipments to expencive for one vehicle I've got access to diagnostic tools but none will connect to the disco ecu)
I was woundering if it could be the turbo boost sensor but not sure of inputs or out puts
re coolant sensor I tried a variable resistor connected to the plug and adjusted the resistance from the info I had and while standing still I could increase the tickover but on the road it made no differance to driveability still slug like
Will kep you updated
One good thing now I have a good understanding of these discos even if I can't fix mine
Was hoping to have it sorted by the weekend as I quite fancied a look to the show in yorkshire but never mind ,might ask the wife if I can borrow her car (some chance )

Good luck Tony,please keep us up to date on your saga,this is turning into a vital resource of EDC info that we need to keep our trucks going as they age.

Wrote all this out before and sodding google chrome crashed,again,and lost the lot......

my 98 300 auto has had this cold start problem since my dad bought it 5 years ago.He threw money at it for 4 yrs,replaced or mended everything imaginable to no avail.And we are not talking minus temperatures here,just overnight,moderately cool.
I have replaced the head coolant sensor (again) and soldered in new wiring to replace the heat damaged stuff but no improvement.I have an ECU but since my others are off the road I dont want to take the bloody thing to bits unless I have another car.
Do the ECUs store fualts,like the ABS one does?Anyone got any new ideas?And does anyone round my way,cornwall,bodmin moor near Trago,have testbook?The local LR garages do obviously,but they want to do the work,not just tell me the fault.Plus Mick Moore and Joe at DP both have had strokes........

Is your starting problem only during cold weather ?
Try searching on here for threads on "cold start problems". There is a modification for this common tdi EDC problem that has been posted.
It involves connecting a resistor into the plug on top of the head and then trying to start the lump. If this improves things, then the fix is to solder a smaller resistor into the wiring and add a momentary switch to the circuit. Fit the switch in a spare bit of the dash.
What it does is to increase the fuelling for cold starts when you push the switch. As soon as it starts you drop back to the standard variable resistance of the head sensor.
I suffered a bout of cold starting problems but mine was down to two other sensors that also interract to affect the starting. The crank sensor and the #4 injector sensor both work together at startup and can really bugger it up.
Fault codes for my motor showed a recorded "engine speed" fault. This can be either of the above sensors.
My problem was fixed by changing the #4 injector. (a lot easier to change than the crank one).

There is also another sensor at the rear of the inlet manifold, on the left side of the engine up against the bulkhead. This is the air temperature sensor. Mine was stuck at -8.
This is another cheap one to swap out.

Davee,anything except hot weather.The head coolant sensor has been changed and had new wiring,,,,,twice,as has the manifold one.I have all the kit for the resistor mod its just getting time to do it.I have a new (2nd hand) ecu to go in,too. In the previous stuff on here and another forum it was said that the only sensors controlling timing on start up were the two I mentioned.I would like to know the correct reading of ALL the sensors.If I could get my other auto 300 finished I could compare to that as that has always been fine,as was the auto I had previously.

If you have the bits for the resistor mod' then try removing the plug in the head and inserting the high value resistor. At least then you'll prove if this part is having an effect on the starting.
Trust me, the crank sensor and the #4 injector sensor play a big part in the engine running. if they get themselves out of sync it is hell to start the lump.
When these played up, I managed to flatten the battery without even a hint of starting!
You'll find you have other problems with #4 playing up though, an intermittent misfire and the possibility of the check engine light flashing on.

If you have a 2nd ecu it's worth trying the resistor trick first, easy option, then trying the ecu swap.

This vehicle has been in the family for 4 yrs or so and has always had this problem,as you say,flattening batteries without a hint of starting.Its had new batteries,starters,alternators,the injectors serviced etc etc ad nauseum.

I would be interested to know HOW to check the No4 injectors sensing role,I assume its by resistance or impedence but short of testing against a known working one,I am at a loss.Likewise the crank sensor.

There hasnt been any misfiring or engine light on since I have had it,my father now has dementia so its no use asking him what it did in his time as the answer will probably be something along the lines of "wibble!" ......

Davee,please dont think I disbelieve what you say,I am only repeating what has been said before,I am very glad of the input - you are the first person who seems to have had trouble with EDC that wasnt cured by the resistor or sensor replacement.....other than me.And since I plan to keep my 300 autos on the road indefinitely I really need t get to grips with this.You said you got hooked up to testbook and it gave a "engine speed" result....that would,to me,point to crank sensor,so I am grateful for your experience.I dont know where the bloody thing is yet (I will find the bugger though).

Anyone with numbers for the testing of No4 injector sensor and the others,please can you post them up,or a link?My workshop manual doesnt give them.

Also,is there anyone in cornwall on here with Testbook access? I can pay handsomely in pork and mutton......

Davee,as to putting the resistor into the plug at the sensor,I tried that before....no good.Since then I have had new sensors and new wiring - but still no change.

I am convinced,from other reading in books and online that there is heat damage to the insulation of seperate wires within the bundled part of the loom,that and oil ingress.What I propose to do about that is to do an extensive cross-continuity test at the ECU plug end,to find out if there is connection to the relevent sensors and if there is any shorting between wires.Then I will try running in fresh wires to the sensors,if need be,and at the same time add a switched resistor and a potentiometer hidden inside the dash so they are in place should they be needed.

This is why I am keen to know correct readings and pin assigns,some I have gleaned from searches here....any more I would be grateful for.Along with my repeated begging for cornish testbook without giving (my) blood.