Had a problem yesterday with engine suddenly having little power,. Driving at about 50 mph the power just dropped off and opening the throttle made no difference. It was just like when I had diesel waxing back in the 1980's and it blocked the filter and restricted the fuel flow. Also similar to when I had a partially blocked pick up in the tank on a diesel Land Rover 90. After a few seconds it picked up again but happened intermittently until I got home. It will start with no problem and it doesn't actually misfire just wont rev when it happens . I changed the fuel filter , bled it ( No problem with the fuel flow) and it started , stumbled a bit as the air cleared then ran OK for a while & then again when I opened the throttle , nothing happened for a few seconds, just ran at idle then suddenly picked up speed. I wondered if its the MAF playing up.
Any suggestions welcomed?
Rover 45 Diesel not revving
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Montegoman
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Re: Rover 45 Diesel not revving
From my experience with the L series in our 25 it does sound like the MAF.
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itcaptainslow
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Re: Rover 45 Diesel not revving
Try disconnecting the MAF; if performance improves, you’ve found the issue.
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220 GSi turbo
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Re: Rover 45 Diesel not revving
Another vote here for the MAF.
If it dies completely (goes open circuit), the ECU assumes it isn't there and uses a 'default' value to keep the engine going (usually results in a rev 'ceiling' of 2500-3000rpm and a bit of a lag when you pull away from junctions etc) but if it only partially fails the ECU will still see it there and process whatever value comes from it. If that value is very low, the ECU will send very little fuel to the injectors!
On a pre-2004 (ish) car you can unplug the MAF and the engine will run in 'default' as mentioned above with no ill effects. On later cars, the engine management warning lamp will come on and will then need to be reset using an OBD-compatible tool when you have had the MAF replaced.
If it dies completely (goes open circuit), the ECU assumes it isn't there and uses a 'default' value to keep the engine going (usually results in a rev 'ceiling' of 2500-3000rpm and a bit of a lag when you pull away from junctions etc) but if it only partially fails the ECU will still see it there and process whatever value comes from it. If that value is very low, the ECU will send very little fuel to the injectors!
On a pre-2004 (ish) car you can unplug the MAF and the engine will run in 'default' as mentioned above with no ill effects. On later cars, the engine management warning lamp will come on and will then need to be reset using an OBD-compatible tool when you have had the MAF replaced.
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Daily: Honda Civic Type R GT
Previously: 216 Sprint (1988-91)216 Coupe(1993-95) 214SLi(1995-96) 420GSi Turbo L955UKV(1997-2004) 214SEi M884BMR(2004-11) 420GSi Tourer (2005-6) 214 SEi M103BCW(2011-12)
1994 216SLi
2000 25GTi
Daily: Honda Civic Type R GT
Previously: 216 Sprint (1988-91)216 Coupe(1993-95) 214SLi(1995-96) 420GSi Turbo L955UKV(1997-2004) 214SEi M884BMR(2004-11) 420GSi Tourer (2005-6) 214 SEi M103BCW(2011-12)
Re: Rover 45 Diesel not revving
Thanks for the replies.
I have disconnected the MAF .and it started with no problem revving at standstill , I then took it of and found it and the air cleaner element were partially wet. There was a lot of spray & water on the road yesterday. Have dried it all in the house, will reassemble and try it out when it stops snowing/raining . Will also check to see if the Shannon tube is intact and not letting in water at the bottom bend
I have disconnected the MAF .and it started with no problem revving at standstill , I then took it of and found it and the air cleaner element were partially wet. There was a lot of spray & water on the road yesterday. Have dried it all in the house, will reassemble and try it out when it stops snowing/raining . Will also check to see if the Shannon tube is intact and not letting in water at the bottom bend
Re: Rover 45 Diesel not revving
Car now running well having dried it all out . Gave it its annual service at the same time including changing all the filters. Found a split in the RH CV boot which was replaced Passed MoT with a couple of advisories on rear suspension bushes.
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StubbornPatriot
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Re: Rover 45 Diesel not revving
Result!
1989 216GSI + 1990 216GSI + 1997 416 Tourer + ? + Triumph T160V
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Frog and Ogy
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Re: Rover 45 Diesel not revving
Hi -
I would also consider for future ref the EGRV (Exhaust gas recycling valve)- had a friends Rover 25 2.0 TD do the same a while ago, struggling to pull, not wanting to rev etc, so after a bit of research, I made a small ally blanking plate to bolt between it and the manifold... and result- back to full life, good punchy lump it was, it also passed its MOT a week later with no emissions issues.
Unfortunately She ran it into a ditch in snow 2 weeks later and wrote it off!
I would also consider for future ref the EGRV (Exhaust gas recycling valve)- had a friends Rover 25 2.0 TD do the same a while ago, struggling to pull, not wanting to rev etc, so after a bit of research, I made a small ally blanking plate to bolt between it and the manifold... and result- back to full life, good punchy lump it was, it also passed its MOT a week later with no emissions issues.
Unfortunately She ran it into a ditch in snow 2 weeks later and wrote it off!
