Rover 75 CDT power loss

Dingatron

Hi All. I'd appreciate a bit of help here. Posted also on the Rover forums also but no replies there. Im not sure if these two issues are both connected but I think not. I bought a 01 CDT a few weeks back and while a bit rough, was driving though a bit sluggish but there was no EML light displaying and it had passed the NCT recently enough. It also had a very slight diesel leak from the rear which I didn't spot at the time but didn't expect that to be a major issue.

Anyway I set out and did a full service on it myself replacing oil, oil filter, air filter, pollen filter, fuel filter, pcv filter, cleaned out the EGR valve, cleared plenum drains and replaced back discs and pads.

Over the last week the leak seemed to get worse and I started to get an intermittent check engine light also. I attributed it to the leak and put it into the garage yesterday. They reseated the fuel tank thinking the the tank seal was the issue but this morning no difference (I now suspect fuel pump O ring maybe). Drove it to the motorway this morning and I could tell the engine seemed to be struggling and if I reduced acceleration The checkengine came on straight away and I was in limp mode unless I took my foot off accelerator full and then depressed it fully again. Temperature gauge is fine and coolant, fuel, oil is not leaking from the engine that I can see. Drove back in home in light traffic taking it handy and while I didn't get any errors I could tell the engine seemed to be struggling.

Anyone any ideas? Garage rang just there and said no error codes were returned from the diagnostics and he took it for a spin with no issues. That leaves me at square one I'd nearly prefer if they'd told me the fuel pump was gone so at least it could be sorted. He also said the fuel tank leak wouldn't affect the fuel pressure but the fuel pump could be faulty and intermittently working although the front pump appears grand and i belive can manage without the back one working if the tank is full which it is.

I think i can test the pumps working but not the pressure and injectors are not leaking either from a visual inspection. He suggested the Egr valve as a possible culprit. I did take it off and clear a lot of the gunk off but didn't clean it with alcohol or the like. Maf is unlikely to be the issue I'm lead to believe and it was changed to a Pierburgh at some stage. I will temporarily bypass the Egr tonight and maybe unplug the MAF also but after that I'm all out of ideas.

Anyone any advice or know of a good Rover specialist in the North East/Dublin area that could take a look?

Dingatron

Dingatron wrote: »

Maf is unlikely to be the issue I'm lead to believe and it was changed to a Pierburgh at some stage. I will temporarily bypass the Egr tonight and maybe unplug the MAF also but after that I'm all out of ideas.

Anyone any advice or know of a good Rover specialist in the North East/Dublin area that could take a look?

If 'twas the Maf the performance would be very bad below 2000rpm ish, it won't show up on diagnostics unless it's completely shot. A shot Maf will also bring on the dash light. Now if it's shot I can't see it being intermittently shot so I agree it's not the Maf unless your performance woes are all less than 2000 ish rpm.

Thing to note though is that the replacement Maf could be giving trouble, lots of non Bosch replacements about and they are sh1t. Even Pierburgh maf can be troublesome within months of installation if contaminated by a clogged pcv valve or dirty airfilter. So if your 75 was gagging for a service I wouldn't discount the Maf.

Dingatron

Thanks Rover. I wasn't happy when I saw the MAF was replaced but the Pierburgh is the ones that are recommended as a good replacement. There is another box hanging off the ECU (size of a cig box) which looks like it shouldn't be there and I'm guessing it is either a mafam or a crappy performance booster type thing.

I lost power at any speed this morning once 15-20 minutes into my trip once acceleration dropped yet got home although with less gear changing and motorway the whole way. All filters have been changed two weeks ago which leaves me wondering did I fit one wrong...

Would you know is blocking the tube attached to the EGR valve enough to disable it short term? Getting dark now so may just hang on until the weekend after my experience this morning.

Anyway I collected it there and its fine for a 10 minute drive.

Dingatron

Dingatron wrote: »

Thanks Rover. I wasn't happy when I saw the MAF was replaced but the Pierburgh is the ones that are recommended as a good replacement. There is another box hanging off the ECU (size of a cig box) which looks like it shouldn't be there and I'm guessing it is either a mafam or a crappy performance booster type thing. ............................

If it's a Mafam or a Synergy2 then email ron@tuning-diesels(add dot com...........I don't want to be getting him bot spammed ), if it's one of his yokes he may well be very helpful

Dingatron wrote: »

Would you know is blocking the tube attached to the EGR valve enough to disable it short term? .....................

Theoretically it should but it's something that conceptually I struggle with :pac: Blanking plates do effect my reasoning there though

Dingatron

Thanks I'll take a photo and see if he can identify it. Just changed the O rings of the inter-cooler to be sure as I had them to do anyway and now going for a spin with the vacuum tube blocked. See how that goes as a starting point.

Dingatron

Only made it 6 miles this morning. in the garage awaiting verdict.:pac:

Dingatron

Quick update

Update
I've got word back from them that the issue is with the throttle potentiometer. Is this the same as a throttle position sensor and does anyone know what part number I should be looking for as I've been left to source one. I've checked Rimmers and come up with the following page but I'm not sure what part number or if diesel is different from the petrol one. It's for a 2001 CDT

http://www.rimmerbros.co.uk/Item--i-GRID001926


Or ebay brings up

http://shop.ebay.ie/?_from=R40&_trksid=m570&_nkw=Rover+75+THROTTLE+POTENTIOMETER