MG ZT CDTI Slow decrease in rev drop

PJB · 18th March 2015, 21:48

Help
I have the MG ZT CDTI 05 (90000 on the clock) remapped to 160 bh.
Before and after the re map I have noticed that the revs take a long time to drop from above 2500 rpm when the engine is hot, the higher the revs the slower it takes the engine to drop to a level where it is comfortable to change gear. Could this be an air leak?.

This is my first diesel so not sure if this is a diesel thing and just have to live with it

I have changed the "O" rings in the inter-cooler, bypassed the EGR, changed the PCV filter, had a full service on the car (air + fuel + oil filters changed). The car accelerates very well with little white smoke. I have even had the ECU checked which returned 3 issues
1. accelerator peddle issue (seems ok and very responsive)
2. Low pressure on the fuel rail system (both fuel pumps are ok)
3. unknown error

I have ordered a new MAF just in case but as stated the car pulls very well form about 1300 rpm

Any help would be appreciated
Thank you

18th March 2015, 21:48	#1
PJB Newbie MG ZT Join Date: Oct 2014 Location: Liverpool Posts: 8 Thanks: 0 Thanked 0 Times in 0 Posts	MG ZT CDTI Slow decrease in rev drop Help I have the MG ZT CDTI 05 (90000 on the clock) remapped to 160 bh. Before and after the re map I have noticed that the revs take a long time to drop from above 2500 rpm when the engine is hot, the higher the revs the slower it takes the engine to drop to a level where it is comfortable to change gear. Could this be an air leak?. This is my first diesel so not sure if this is a diesel thing and just have to live with it I have changed the "O" rings in the inter-cooler, bypassed the EGR, changed the PCV filter, had a full service on the car (air + fuel + oil filters changed). The car accelerates very well with little white smoke. I have even had the ECU checked which returned 3 issues 1. accelerator peddle issue (seems ok and very responsive) 2. Low pressure on the fuel rail system (both fuel pumps are ok) 3. unknown error I have ordered a new MAF just in case but as stated the car pulls very well form about 1300 rpm Any help would be appreciated Thank you __________________ MG ZT CDTI Purchased on the 10/2014 Fixed boot leaks Fixed bonnet cable + catches New clutch S+M New Wheels + Tyres Plenum cleaned + mod Fixed airbag warning light New Battery PCV filer replaced Quantum blue remap to 160 bhp New Bosh MAF Break disks & pipes replace New Alternator Engine mounts replaced Aircon pipes replaced Intercooler seals replaced In the boot with a tube of silicone, a torch and a box of Kleenex, "it's not what it looks like officer"!