OK, here's the story, a year ago my 95 DSE was getting difficult to start, the Rovecom told me the glowplugs were down, bought 6 new Bosch units, fitted, perfect!!
Not being overly impressed with the diesel's 'pulling' power, I fitted & tuning-chip box, this made quite a difference in torque & acceleration, ( I pull a big trailer a few times a year) BUT, it DID make it smoke, something it never did before!
A few weeks back, as it was turning colder, it again became more & more difficult to start, good job I had a new battery 'cos it was turning over for up to 40 seconds before starting, once it did, it was fine all day, starting on the button, so, I hooked up the Rovercom again & it told me that the glowplug control was down, shot out & bought a new one, no different!! Checked for a supply at the plugs, 12v, so I whipped them out, ALL covered in soot & 3 of the 6 not working!
Shoved in 6 new ones (again) & all well, starting on the button, BUT, now I had the dreaded 'bubbles in the fuel line' AAARRRGGGHHH!
Thinking that the in-tank fuel pump had failed, I removed the new fuel filter, switched on, nothing coming through, then checked the fuse (39) & it was blown, replaced, still no fuel, BUT when the filter was re-fitted, NO air bubbles & it now starts & runs fine, AND the chip-box has been disconnected.
The car now, however, seems really down on torque, struggling up hills etc.

Now for the questions,
1: Would a 'sooted' glowplug still glow!
2: Is it possible that the in-tank fuel pump is somehow down on power & thus causing the lack of 'ommph', it not smoking at all now & the engine must be relatively healthy due to its easy starting.
I'm a bit concerned about re-fitting the power-box due to the smoke & sooting of the plugs.
3: Could the injector pump be 'down' & cause the lack of power??
Sorry for being a long post, but you need to know the full story!!
BTW, my rovercom tells me all is ok & no faults logged.

Replaced my glow plugs today due to it slow starting and they were all completely sooted up, my diesel isn't chipped either.

From what I've read on here, glow plugs failing to work after a year isn't unusual.

Have you checked the spill return hoses from the injectors? These perish allowing air into the system letting diesel run back to the tank. Also a split pick-up pipe on the pump in the tank allows diesel run back when the tank is 1/4 full.

My spill return hoses were okay, now it starts on the second turn. It won't be like that in a year though I imagine!

Thanks for that, but all pipes ok, no diesel leaks & no air leaks, starts in less that 1 revolution, & runs perfect, its just that its got no torque ( read power) like it used to, I wonder if the in-tank pump is 'down on power' & thus feeding the injector pump with less than spec pressure & therefor resulting in my lack of 'oommpphh'!!

The in-tank pump is just a lift pump to get the diesel up to the injection pump and that is where the high pressure is generated and the pressure is controlled within the pump.

Check your air intake system too, starting with the filter; then all the hoses, these can collapse or leak under vacuum/pressure; and the intercooler could be blocked.

Whilst having my air intake system apart at the weekend I couldn't believe how much oil sludge had accumulated in the intake manifold and the ports - I'm sure the intercooler must have restricted passages too so that's next on my list.

Brand new K&N air filter, plus brand new intercooler hoses, I even disconnected the outlet from the intercooler hose & ran up the engine, the blast of air was consistent with engine revs, good flow when running, like a jet engine when revved!!
I'm certain the intercooler is clear, took the feed pipe off the fuel filter today, nothing came out at all, even with the ign on & engine running!! Somehow its running by the injector-pump pulling the fuel.
Its going in on Friday to have the tank dropped & a new in-tank pump fitted.

I'm sure that as soon as you turn on the ignition the tank pump runs for about 10 seconds as when I changed my diesel filter, I turned on the ignition and could see the bubbles moving along the clear pipe after the filter for about the first 10seconds and then they stopped, I turned the ignition off and back on and the pump ran again. I did this a few times to get the air out of the filter until there were no more bubbles and then started the car as per normal.
It does sound like your pump has died or has lost it's power! Good luck with it and do keep us posted on your progress.

Well, after a bit of a disappointment due to my local guy forgetting to order the pump, today she went in for the in-tank pump replacement, £275.00 I don't mind that, but WOW! Its a different car, goes like sh*t off a shovel, its NEVER gone like this in my 3 years of ownership, AND I havn't reconnected the powerbox yet>
Got the old unit from the guy, took it in the garage, hooked it up to a 12v battery, & it sort of 'crunkled' for a few seconds then stopped, it did this every time, so the motor was shot, bigtime.
So to any of you 'oil-burners' out there, if your waggon is sluggish & you've tried most things, consider changing the in-tank pump.
Mine was somehow 'pulling' the fuel up via the injector pump with no head at all from the tank unit, so it was down feed pressure & running on what little the FIP was providing, i'm amazed it ran at all.

Another question ,but really for you guys who KNOW diesels, I took it back to the fitter who replaced the pump, & asked him if was ok to try the power-box tuning chip, 'cos since it smoked before, I'd removed it, his reply surprised me,
'The way your car goes now, I'm telling you its ALREADY chipped- & I should know, I've driven loads & yours is a rocket by comparison'!!
Then I pulled the power-box from my pocket & said 'hows that then'!!
So it possible that the previous owner had one of those replacement-in ECU chips fitted, but how do I find this? ALSO, since I tried a tuning-box on the car which ALREADY had a chip, could this have caused the smoking?? & can you 'chip' a chip'???
Took it out for a 50 mile run over the moors today, & its like a new car, & I found myself tear-arsing around as if in a sports-car!! LUVVIT!!

Jeremy J Fearns do the ECU chip upgrade, would have thought it'd be difficult to tell if it had been done unless they put a sticker on the ECU. Even if you opened the ECU you may not be able to tell.

Is your intercooler standard? If someone's gone to the trouble of chipping the ECU they may have upreated the intercooler too.

Let us know what mpg you get now.

So you selling your powerbox then?

Not sure yet, going to run it for a week or two, to get used to it, then I may hook it back up & see what happens!!

I'm like a dog with two dicks at the moment.