Hi
My 2003 2.0 Hdi 180k miles has recently started having a big flat spot in the power band between 1500 -2000rpm . If I change down a gear it then pulls well when the revs are higher. It starts and idles fine but It doest seem to have the go it used to have on hills. Any ideas on where to look first .
My of tester won't connect to it as I think it is just a year to old being 2003.
Thanks jeff

Might be the MAF, try disconnecting it and see if it makes any difference.

(16-02-2021, 08:49 AM)cancunia Wrote:  Might be the MAF, try disconnecting it and see if it makes any difference.

Thanks for the advice. I have disconnected the MAF sensor and driven it round the block and it feels like a dfferent car. What would happen if you just leave it unplugged or should I get a replacement .
Thanks jeff

If the EML does not come on, you can leave the MAF disconnected, the ECU uses a default map. On my 2.0 it would light the EML so an MoT failure. If you leave it disconnected & the MoT tester notices, you'll get a failure.
FWIW, I think a good MAF will help the engine run more smoothly but it's a matter of personal choice.
I bought mine from this place (check the part number & fitment in case I got the wrong engine), it worked fine ,I sold the car about a year later.
https://www.ukdieselparts.com/mass-air-f...232888.htm

(16-02-2021, 10:28 AM)cancunia Wrote:  If the EML does not come on, you can leave the MAF disconnected, the ECU uses a default map. On my 2.0 it would light the EML so an MoT failure. If you leave it disconnected & the MoT tester notices, you'll get a failure.
FWIW, I think a good MAF will help the engine run more smoothly but it's a matter of personal choice.
I bought mine from this place (check the part number & fitment in case I got the wrong engine), it worked fine ,I sold the car about a year later.
https://www.ukdieselparts.com/mass-air-f...232888.htm

Thanks for your help , much appreciated. I will replace the MAF sensor then ,I will check the part number and get it from the company you sent the link from ., the engine is totally original at 181k still on original injectors , I have replaced most of the rest of the car though ! It's a bit like triggers broom .

All very interesting! My 2003 2.0Hdi also starts and runs fine, as it always has.

Not driven it much in the last 3 years but I have been wondering recently if the slight hesitation I get at around those revs is something new. It doesn't pull as well at low revs in third but might be me.

Something to have a fiddle with at some stage

(16-02-2021, 11:32 AM)bikerbaker Wrote:  All very interesting! My 2003 2.0Hdi also starts and runs fine, as it always has.

Not driven it much in the last 3 years but I have been wondering recently if the slight hesitation I get at around those revs is something new. It doesn't pull as well at low revs in third but might be me.

Something to have a fiddle with at some stage

I have just taken it for a longer drive and it drives so much better . The MAF sensor sits right on top of the engine so is very easy to disconnect to try it out . Mine won't connect on odb2 to my reader and I was a bit worried it might bring the light up but it hasn't on mine.

Disconnecting the MAF will make the engine run better as like cancunia says the ECU sets a default map.

I would be inclined to reconnect the MAF and disconnect the EGR valve to see if this cures the flat spot, if it does then the problem could be the EGR valve sticking, giving it a clean and reconnecting may solved the problem.

I believe that disconnecting the EGR on the 2.0 HDi causes the EML light to come on, but I think the light will go out once you reconnect it, is that correct cancunia? I know you have a lot of experience of this engine.

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(16-02-2021, 12:24 PM)jj9 Wrote:  I believe that disconnecting the EGR on the 2.0 HDi causes the EML light to come on, but I think the light will go out once you reconnect it, is that correct cancunia? I know you have a lot of experience of this engine.

I messed around quite a bit with the EGR on my 2.0 after it went into limp mode. At first I thought my MAF problem was an EGR problem as the error code indicated an excessive air flow or something like that. I changed the EGR vacuum solenoid, it made no difference. Disconnecting the EGR gave an EML, I blanked the EGR it gave an EML. I changed the MAF and all was well again. I can't remember exactly but I think it was at around 130k miles when I sold it.

I think a lot of problems with lack of power may be MAF or at least MAF related so it's always worth a quick disconnect to see if things change. Being a glutton for punishment, I currently have a Volvo C30 1.6HDi 110 BHP, same as the Berlingo etc & a Pug Expert 2.0 HDi. When I first got the Volvo, there was a lack of power which was put down to the turbo actuator solenoid, I changed that which made no difference, then I tried to clean the MAF which made it worse so I changed the MAF and it was fine.

Yeah the MAF can cause a lot of problems and cleaning doesn't always work.

With Riggsy's fault I would just be inclined to rule out an EGR fault before buying a new MAF.

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