Disco 2 I'm an idiot, second opinion please (harness mis-match)

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H

HasisD

Member
Posts
89
Location
Bentham, N. Yorks
Hi Chaps
So, I have a Disco 2 TD5 with >134k miles.
Two years ago I fitted a new injector harness, but didnt tell the ECU (coz I didnt have diagnostics).
Since then, I've had no trouble at all with normal driving, but if I go over 3k revs, there's been a stutter. I am an advanced trained driver (I'll say no more), so the not going above 3K isn't because I'm not 'speedy', it's just that...<3K seems to be the sweet spot to keep my engine ticking over smoothly, with no unnecessary fuss.

Today, towing the caravan along the A30 and up Sourton Cross I lost momentum and dropped to 4th, upped the revs...and I thought I thrown a prop shaft the stutter was so bad. It scared the BeJesus out of me, so I coasted to the top and off the off slip, pulled to a stop ...and noticed that engine was still merrily ticking over. Turned it off and on again...and we were back to normal, as though nothing had happened.

Continuing west I suddenly remembered a thread here (that I now can't find), when you told someone that you need to 'train' an ECU to accept a new injector harness...otherwise it starts to misbehave at >3K revs.

So have I today simply experienced a problem that I set in place 2 years ago, when I didn't train the ECU?

If so, have any of you got an idiots guide (yes, coz I'm an idiot if this is all the problem is) to using Hawkeye to rectify this problem (i.e. I have Hawkeye and tools with me)?

Thank you in advance, if this is as easy to sort as I hope it is.
H
 
HasisD said:
....you need to 'train' an ECU to accept a new injector harness...otherwise it starts to misbehave at >3K revs.
Click to expand...
Might be a misunderstandig, the injector harness is no factor, you have to program the ECU only if you change injectors to save the new codes... the >3k revs missbehaviour can be a symptom of incorrect injector codes so you have to see the actual codes on the solenoids and compare with what's stored in the ECU memory... though there can be many other causes for the symptom you describe but to be able to give some hints you must describe well the vehicle e.g is it 10p/15p, any fault codes? EGR stil on?, CAT on?, etc
 
Thanks SF.
I haven't checked for fault codes yet (trying my best to reduce likelihood of domestic by just focussing on 'holiday'), but will now do so tomoz and come back. It's a '03 facelift with no CDL, EGR still on, Cat still on...it's a very tidy example of standard. If that helps?
H
 
Oh, what am I talking about, it's not 'standard'...It's had a tune from ...Oh Christ I've forgotten his name now...Dave? Transformed it into a dream to drive, and I would really feel wrong to suggest the stutter is anything to do with the tune.
 
Then the EGR and CAT(especially this) can be the cause of your problem... as first step see if there are any codes logged, clean the MAP sensor cos it's probably gunked up by the EGR.... unplug the MAF and see if it's better that way, eventually if you can go somewhere where the noise is not an issue make a short drive test with the downpipe bolts loosened as to have some flow there and if it's better get rid of that CAT cos it's clogged
 
So the only code I get on EMS is a 3141 'Driver demand fault' [seems a little harsh, I just wanted it go go up the hill :(]. Will try your suggestions tomoz.
Thanks again H
 
Unless the throttle position sensor is not making tricks which acordintg to the symptom is not very likely this code used to come on when there is low fuel presure which means that it's possible that the pump's HP stage is gone or there's an issue with the FPR.
 
HasisD, this sounds to me more like you have a problem with the wastegate. The symptoms are exactly what you describe, maybe the nuts holding the can have come loose. Happened to me one Christmas hol in Cornwall. Was a real pain. The ECU detects the fault at higher revs, thinks the throttle wants too much fuel so puts it into limp home mode, which is then reset by stopping and turning the engine off. Until you drive off and do it again! Check a/ that the can is securely attached to the mount, (two m10 nuts and hopefully lock washers) thenb/ check that you have roughly 13 threads showing between the locknut on the threaded rod and the end. (Rough check only).
 
PS, 3000 revs might be a "sweet spot" but 2000 revs is the most economical! But I know what you mean when you are on a motorway or something. PPS when I said M10 nuts I was wrong you need 10mm spanner to do them up, in fact they are m6 nuts.
 
Stanley Thank you!!!
I've been thinking about the waste gate so will check that during first parade tomorrow.
This morning, thinking about the EGR, I pulled out the MAP, which was ...as clean as a clean thing. However, I also remembered a couple of months ago putting Hawkeye on and finding two fuel-related codes...which I ignored and cleared without writing them down, because I didn't have any fuel issues at the time (Reader: please refer back to the title of this thread).
Keeping below 3K today (for domestic reasons as much as anything) things have been as uneventful as everything west of Sourton Cross yesterday. In relation to pogoing down the road at least. However, the bloody intermittent fan belt squeal is back...it just appears to be doing it on purpose now to keep me on edge.
SierraF...are we talking new fuel pump and fuel-pump relay, if it is that side of things?
PS. I still love my Disco (and have had a couple of pints of Cornish ale) and the Roseland Peninsula was beautiful today, if a little bracing.
 
HasisD said:
SierraF...are we talking new fuel pump and fuel-pump relay, if it is that side of things?
Click to expand...
If that's the case as long as you hear the pump running you dont need a relay but you might need a new pump... as i said the driver demand fault code can be triggered by faulty TPS(which woud cause different issues than yours) or low fuel pressure which would match your symptoms
 
HasisD said:
Stanley Thank you!!!
I've been thinking about the waste gate so will check that during first parade tomorrow.
This morning, thinking about the EGR, I pulled out the MAP, which was ...as clean as a clean thing. However, I also remembered a couple of months ago putting Hawkeye on and finding two fuel-related codes...which I ignored and cleared without writing them down, because I didn't have any fuel issues at the time (Reader: please refer back to the title of this thread).
Keeping below 3K today (for domestic reasons as much as anything) things have been as uneventful as everything west of Sourton Cross yesterday. In relation to pogoing down the road at least. However, the bloody intermittent fan belt squeal is back...it just appears to be doing it on purpose now to keep me on edge.
SierraF...are we talking new fuel pump and fuel-pump relay, if it is that side of things?
PS. I still love my Disco (and have had a couple of pints of Cornish ale) and the Roseland Peninsula was beautiful today, if a little bracing.
Click to expand...
Hope for your sake it IS the wastegate, as it'll cost nothing to fix.
Are you sure it is the fan belt squeaking? I thought mine was, ... turned out to be the exhaust manifold was warped.! Hard to believe they sound so similar.
 
Nope, sadly wastegate appears to be fiiiine. So, still thinking fuel pump as possiblility for that.
Manifold...Oh!
I very scientifically dumped a load of WD40 onto my alternator pulley this morning (i.e. test them one at a time I thought) and was treated by some very pleasurable silence for an hour or two of bimbling around. The squeal then started to come back despite additional WD.
So, warped manifold. What exactly were the symptoms of that Stanley?
PS. West Cornwall today, Hayle roadworks a flaming nightmare (although Philps pasty made up for much of that) and a hail storm on St Ives beach. Cracking day regardless.
 
As far as I can remember, there was a whistling/whining/squealing sound which, as I said, I thought was a drive belt. I think it got louder as you put your foot down. Anyway, once I knew what to look for, it was pretty obvious., there was a gap where there should not have been one at the number 1 cylinder end of the exhaust manifold, also studs and nuts were missing on numbers 1 and 5. If yours hasn't gone yet I'd be tempted to take it off and cut through the webs between the pipes, you could also open the holes that go over the studs, by 1mm for 2 and 4 and 2 mm for 1 and 5. But I expect other members of the forum will tell you to simply buy a new manifold. They are not wrong, I just like to save money where poss.

Thinking about your issue, When you changed the injector harness did you do anything else at all? Did you clean out the plugs into the ECU? Did you open up the ECU to check there was no oil actually in there? I agree wholeheartedly about the fuel pump although I would like to see it tested off the car, although I would not know how to do that with any accuracy. Actually, "off the car" is a stupid thing to suggest, but, with the pipes disconnected maybe there is some way of connecting it directly to a power supply and test it for high enough output. Does that make sense? I take it you have checked for a blocked fuel filter. Best of luck and do enjoy the rest of your holiday!
 
Stanley...thanks for that.
I've looked at the manifold today and can see no evidence of gas leakage or stud damage, but WD once again worked on the alternator pulley...so I'm going to focus there. Re the ECU, yes, when I replaced the harness I also cleaned the red plug and popped the lid off the ECU to check, but there was no oil contamination in there.. However, that's a year or so ago now so I think I'll do that check again.
PS. Beach to ourselves at Chapel Porth this morning. Low tide, no footprints but our own and north-westerly wind-driven sleet showers...made for a fab experience (and put an annoying squeek into perspective)
 
Glad about the manifold.
Don't forget WD is not really a lubricant, in fact once used to free rusty metal there is evidence it can actually lead to further rust. But it is not easy to lubricate a pulley wheel that is not intended to be lubricated. Maybe you could find some way of very carefully using a silicone lubricant. But I'd be careful of not getting it on the friction face of the belt.
Belts can be dressed, but if they are on the way out...
ECU clear last year, good.
So still no nearer solving the rough running. What a shame. No doubt once you get back home you'll have a better chance of sorting it.

Cornwall, like so many holiday areas, is so nice out of season. Glad you're enjoying it! We were there at Christmas 2017, and it was great, (although running up and down the A30 with the aforementioned dodgy waste-gate can, was not much fun. We were nowhere near any DIY shops that were open during the holiday. Had loads of tools but could not find a spare M6 nut! (Managed to to pinch the another one off something else on the car.) Just had to go annoyingly slowly up the hills!) We were staying in Altarnun. We really must get back to the Camelot Hotel, Tintagel, as we promised ourselves!
Hope the recent weather change is not doing too much harm.
 
HasisD said:
SierraF...are we talking new fuel pump and fuel-pump relay, if it is that side of things?
Click to expand...

By FPR SierraF means the Fuel Pressure Regulator. If something is limiting fuel flow at high rpm, I would have thought the FPR has to be a potential culprit.
If the squealing is coming from the aux belt area, then unless you have done so very recently, I would plan on swapping the belt with a good quality replacement. WD40 or chalk can work for a while, but a worn belt is your most likely culprit. You can check the wear on the tensioner and auxiliary pulleys while the belt is off and if they are the problem and the belt is good, then you have bought yourself a very sensible in-car spare.
 
Si Click said:
By FPR SierraF means the Fuel Pressure Regulator. If something is limiting fuel flow at high rpm, I would have thought the FPR has to be a potential culprit.
If the squealing is coming from the aux belt area, then unless you have done so very recently, I would plan on swapping the belt with a good quality replacement. WD40 or chalk can work for a while, but a worn belt is your most likely culprit. You can check the wear on the tensioner and auxiliary pulleys while the belt is off and if they are the problem and the belt is good, then you have bought yourself a very sensible in-car spare.
Click to expand...

+1 on that. I have always carried a spare fan belt, as we used to call them, in every car I have ever owned. Just like carrying an umbrella, they keep the rain away! To date the score has been - fan belts gone - 1, timing belts gone - 1. The fan belt was on a Renault 17 (who can picture one of those? Great fun!) And, 'cause it was the one that only drives the alternator, unnoticed until eventually saw the ignition light on. The timing belt was luckily on a 1600 Pinto (Ford) engine turning at just over tick-over so no harm done and repaired at the roadside 100yds from my house. So, with an even score I am beginning to think a timing belt should become an "always carry" But then most of the time, if they go, they cause horrendous damage! Better to renew well ahead of time.
Would just cleaning the FPR sort it? What about unplugging it temporarily, would not that put it into "get you home/limp mode", in which case she could drive it to a garage, or a mate with a diagnostic? (Just asking, Don't know much.)
 
Oops! Did not mean "she"! Have just been posting on another thread where the OP is a "she". Sorry HasisD, just noticed you are a fellow Yorkshireman, although I'm from Hull about as far away from you as can be and still be in the county!
 
Stanleysteamer said:
Would just cleaning the FPR sort it? What about unplugging it temporarily, would not that put it into "get you home/limp mode", in which case she could drive it to a garage, or a mate with a diagnostic? (Just asking, Don't know much.)
Click to expand...

The FPR is an integral part of the fuel system hardware. It can be replaced easily enough (once you figure out which gasket you need), but you cannot just disconnect it and have the engine limp home any more than you could just remove the fuel filter and expect the engine to run.
 
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