Turbo lag on CDT

wmick · 7th September 2016, 18:20

I've had the saloon 6 years now and it's never been brilliant at pulling away from a standstill, but I've just changed the airfilter for a K&N one, cleaned the EGR (urgh!), changed the PCV and cleaned the manifold pressure sender, and it seems worse than before, although not as smoky.
I've never noticed any "turbo lag" on the Tourer, but it's very obvious now on the saloon. I can accelerate away from a 30 limit in 5th with my foot through the floor and it gathers speed very gently until it gets to 2000 rpm (60 mph) and then it goes like stink. If I want make decent progress I have to go through the gears and rev it, which is pain when towing the van (max legal speed 50!)
Has anyone any ideas as to what causes the difference in performance between the 2 cars (apart from Brian providing me with a new ECU a couple of years ago)?

Mick

spyder · 7th September 2016, 19:18

Is the K&N filter a oil one or a standard fit insert type. Either way a duff MAF would cause "turbo lag" symptoms.

klarzy · 7th September 2016, 19:19

check for leaks or porous intercoolervtop hose or elbow orings..
also check for leak from metal flexi on rear of egr...

ZedTeeT · 7th September 2016, 19:21

Hey Mick, could possibly be the MAF failing, but I'm sure someone more knowledgeable than me will be along soon!

wmick · 7th September 2016, 19:28

Thanks chaps for the replies.
I've got a replacement MAF on order, but I swapped the one out of the other car to check it and it seems to be the same.

Mick

ZedTeeT · 7th September 2016, 21:00

Well it sounds like your not losing boost pressure as it's spot on at 2000rpm plus which would also indicate that there is no problem with fuel pressure or delivery. You say that it's smokey too...... Hmmm, have you tried it with the MAF disconnected?

marinabrian · 7th September 2016, 21:10

Mick, unplug the electrical connector of the EGR actuator solenoid and try that, sounds to me as if the EGR valve is a little lazy in closing

Brian

wmick · 8th September 2016, 10:22

After a bit of testing, disconnecting the EGR valve didn't make much difference but I did notice a misfire when I got to 3000 rpm in higher gears ( nobody was looking!)
Terry Shaw replaced one injector at the same time as the ECU replacement, perhaps they all need doing

Mick

pletevl · 9th September 2016, 07:46

Quote:

Originally Posted by marinabrian

Mick, unplug the electrical connector of the EGR actuator solenoid and try that, sounds to me as if the EGR valve is a little lazy in closing

Brian

Brian, where is this ? my CDTI has a vacuum pipe going to mine, i have never seen an electrical connection

Pete.

TomRS · 9th September 2016, 08:35

Sounds like MAF.

Missfire will be down to dirty/damaged injectors or if you have a tuning box make sure its wired correctly as i had a horrendous missifre when i accidently put the box the wrong way round (MAF connector) and it took me ages to figure it out.

If your stock then its either low fuel pressure, air leak into the system or more likely a blocked injector tip.
They can be removed by yourself and sorted easily

7th September 2016, 18:20	#1
wmick Avid contributor R75 Club Tourer CDT Join Date: Jan 2011 Location: Craven Arms Posts: 135 Thanks: 25 Thanked 20 Times in 16 Posts	Turbo lag on CDT I've had the saloon 6 years now and it's never been brilliant at pulling away from a standstill, but I've just changed the airfilter for a K&N one, cleaned the EGR (urgh!), changed the PCV and cleaned the manifold pressure sender, and it seems worse than before, although not as smoky. I've never noticed any "turbo lag" on the Tourer, but it's very obvious now on the saloon. I can accelerate away from a 30 limit in 5th with my foot through the floor and it gathers speed very gently until it gets to 2000 rpm (60 mph) and then it goes like stink. If I want make decent progress I have to go through the gears and rev it, which is pain when towing the van (max legal speed 50!) Has anyone any ideas as to what causes the difference in performance between the 2 cars (apart from Brian providing me with a new ECU a couple of years ago)? Mick

7th September 2016, 19:18	#2
spyder This is my second home 75 CDT Auto Tourer , Rover 45 , Astra, Zaffira, Chev Captiva Join Date: Mar 2011 Location: Wilts Posts: 3,342 Thanks: 203 Thanked 436 Times in 360 Posts	Is the K&N filter a oil one or a standard fit insert type. Either way a duff MAF would cause "turbo lag" symptoms. __________________ Chrome skull caps, EGR cleaned (original housing), Mondeo lower mounting, 12V outlets in the armrest and tourer boot, cat fixed, working FBH, Lidl plenum covers, DD with reverse camera.New speakesr/Tweeters with MDF rings. wood dash, Memory leather seats, wooden finished steering and handbrake, Xenon headlights.

7th September 2016, 19:19	#3
klarzy This is my second home none but not gone Join Date: Mar 2013 Location: March, Cambs Posts: 16,437 Thanks: 894 Thanked 4,247 Times in 3,025 Posts	check for leaks or porous intercoolervtop hose or elbow orings.. also check for leak from metal flexi on rear of egr... __________________ [SIGPIC][/SIGPIC]….All praise Bananaswan…. Last edited by klarzy; 7th September 2016 at 19:22..

7th September 2016, 19:21	#4
ZedTeeT Gets stuck in MG ZT-T Join Date: Feb 2016 Location: Horsham Posts: 874 Thanks: 197 Thanked 239 Times in 207 Posts	Hey Mick, could possibly be the MAF failing, but I'm sure someone more knowledgeable than me will be along soon! __________________ My garage. 03/53 MG ZT-T+ CDTi auto in XPG. 232k and much to do! 21/21 MG ZS ev. Daily. 85/C Capri 2.8i Special. Mine 29+ years. 82/X Talbot Tagora SX V6. Restoration project. 11/11 Hyundai I Load CRDi. Van....... nuff said.

7th September 2016, 21:00	#6
ZedTeeT Gets stuck in MG ZT-T Join Date: Feb 2016 Location: Horsham Posts: 874 Thanks: 197 Thanked 239 Times in 207 Posts	Well it sounds like your not losing boost pressure as it's spot on at 2000rpm plus which would also indicate that there is no problem with fuel pressure or delivery. You say that it's smokey too...... Hmmm, have you tried it with the MAF disconnected? __________________ My garage. 03/53 MG ZT-T+ CDTi auto in XPG. 232k and much to do! 21/21 MG ZS ev. Daily. 85/C Capri 2.8i Special. Mine 29+ years. 82/X Talbot Tagora SX V6. Restoration project. 11/11 Hyundai I Load CRDi. Van....... nuff said.

7th September 2016, 19:28	#5
wmick Avid contributor R75 Club Tourer CDT Join Date: Jan 2011 Location: Craven Arms Posts: 135 Thanks: 25 Thanked 20 Times in 16 Posts	Thanks chaps for the replies. I've got a replacement MAF on order, but I swapped the one out of the other car to check it and it seems to be the same. Mick

7th September 2016, 21:10	#7
marinabrian MG ZT Join Date: Jan 2011 Location: Newcastle Upon Tyne Posts: 20,151 Thanks: 3,565 Thanked 10,837 Times in 5,718 Posts	Mick, unplug the electrical connector of the EGR actuator solenoid and try that, sounds to me as if the EGR valve is a little lazy in closing Brian

8th September 2016, 10:22	#8
wmick Avid contributor R75 Club Tourer CDT Join Date: Jan 2011 Location: Craven Arms Posts: 135 Thanks: 25 Thanked 20 Times in 16 Posts	After a bit of testing, disconnecting the EGR valve didn't make much difference but I did notice a misfire when I got to 3000 rpm in higher gears ( nobody was looking!) Terry Shaw replaced one injector at the same time as the ECU replacement, perhaps they all need doing Mick

9th September 2016, 08:35	#10
TomRS Posted a thing or two Mk1 ZT 190 - Mk2 ZS 180 - Mercedes E63 AMG S - Ford Ranger Hawk Join Date: Mar 2016 Location: Middlesbrough Posts: 1,456 Thanks: 123 Thanked 409 Times in 281 Posts	Sounds like MAF. Missfire will be down to dirty/damaged injectors or if you have a tuning box make sure its wired correctly as i had a horrendous missifre when i accidently put the box the wrong way round (MAF connector) and it took me ages to figure it out. If your stock then its either low fuel pressure, air leak into the system or more likely a blocked injector tip. They can be removed by yourself and sorted easily __________________ http://i66.tinypic.com/5cd6xj.jpg