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(Post Link) post #1 of 21 Old 02-08-16 Thread Starter
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Power problems on 147jtdm

Hi to all I have problems with acceleration I blanked the egr valve and the power came back about 75persent.I unplugged maf no increase I checked all the pipes an putted two new turbo pipes top and bottom I checked all the small pipes on the vnt system found no cracks or holes.my turbo kicks in at 2300rpms and it is not kwl if you drive in town and want to pull away from a robot and ther is no power.please any help will be appreciated.
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Sounds like vnt as no code generated. I would replace the vnt vacuum hoses even though you say they look ok. Even the smallest of cracks can lose vacuum.
Further investigation of the vnt solenoid is then needed before you start to worry about sticking vanes.
Does the vnt plunger move? Have you measured the vacuum?
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The vnt vanes moves freely when I start the car the rod moves down and when I shut the car off it takes like 10seconds then it springs back to close position.just a stupid question if I blank my egr valve off is ther any possibility that It can damage the enjin?
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The vnt vanes moves freely when I start the car the rod moves down and when I shut the car off it takes like 10seconds then it springs back to close position.just a stupid question if I blank my egr valve off is ther any possibility that It can damage the enjin?
Sounds like that's working correctly then.

EGR blank is a good move. It won't damage the engine, but it will generate an error code. So long as you leave the EGR valve plugged in and a plain blank fitted, you can safely ignore the error code.

Did you check your MAP sensor after blanking the EGR? Not uncommon for these to be so dirty that they look like lumps of coal.. Can be a cause of poor running/power etc. 1 Screw to pop it out, clean it up with some carb cleaner, and see if your power comes back.

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I did fit a new Maf and did check the plug and sprayed it clean.nothing changed still turbo kicks in at 2300-2500rpm.I blanked the egr about a month ago and the power became beter but it feels like I'm running 75persent power when turbo kicks in but under 2300rpm it feels like I'm running a non turbo car can hear turbo spool up but no power.
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MAP sensor, not the MAF!

Both can cause power issues.
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(Post Link) post #7 of 21 Old 02-08-16 Thread Starter
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I just took it out and sprayed it and wented for a drive still nothing turbo kicks in at 2300rpm
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is there any smoke out the back when you accelerate from low down?

if so this would imply some boost leak somewhere , or VNT vac hose as said previously, just because it operates freely on switch on/off does not mean it will be operating under load, I would change the vac hose just to be safe.

then onto the MAF, was the replacement genuine Bosch? if not it could still be an issue as these cars do not like aftermarket mafs, next onto the MAP sensor , if cleaning has not solved it then a new one may be in order, Lambda sensors can also present exactly like maf failure on the JTD engine, good article on the alfa workshop website about this..I would look at the vnt actuator solenoid as well.

and finally the Garrett calibration parameters on these turbo's is actually quite wide as the flow bench software used to calibrate them gives either a green or red light, however ''in spec'' can be anywhere from 1500 rpm spool to over 2k, and its been said on many occasion that some JTD's ''just don't pull from down low'' meaning they are on the upper end of a ''pass''

if you rule out all of the usual suspects in the power train it will then come down to VNT calibration and you will have to decide whether to take the turbo off the car and have it looked at.

good luck..

GT blackline,Bilstien B12's and Eibach Anti roll bar kit,Quaife Diff,Autolusso performance pads, de-cat downpipe,hybrid turbo,stage one clutch,autolusso re-map, swirl flap and egr delete, leon cupra front splitter,novitec light covers,simone racing gear knob.
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Thanx for the perfect sum up but Wat is lambda first time hearing that?
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Thanx for the perfect sum up but Wat is lambda first time hearing that?

lambda is your O2 sensor in the down pipe, post combustion..it tells the engine how much O2 is in the exhaust gasses and if its reading off the ECU will compensate by restricting fuel delivery...which will feel the same as a twonky maf.


have a read of this


Diagnosing a MAF problem
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Awosme stuff now I learned something new now the question is were wil it be on a 147jtdm 16v lusso
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should be clearly visible from under the car, its the only ''thing with a wire connected to it'' on the downpipe.


I would rule out the other stuff first though as they are more likely culprits than the lambda.

good luck, these issues can be a pain to track down but are usually the same few things...just methodical approach and you will sort it..
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(Post Link) post #13 of 21 Old 02-08-16 Thread Starter
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One more question how much miles can the car do before serious stuff starts braking dew to age and miles driven.I replaced flywheel and clutch 5000miles ago I replaced all 4 glowplugs new turbo pipes new maf new map sencor.I also replaced one outer cv 1000miles ago I replaced all 4brake pads and did my full service 3000miles ago car is now on 136000miles.
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well the service life of the JTDm engine according to a fiat tech I know was meant to be 300,000 miles.

so quite a while yet. it's likely other things will make the car uneconomical to repair before the engine gives out.. sounds like you have done fair bit so should be fine, be aware suspension ,especially front upper and lower wishbones are a regular item and keep an eye on the oil cooler pipes as if they let go you won't be a happy man. worth a visual inspection and if all good some rubbing down to get rid of surface rust and some rust proofing on them.

136 K is approaching the service life of the turbo with 150 -160 considered about the point at which they need replacing /refurbing..if you have a CF4 engine then inlet manifold swirl flaps are either already gone or hanging on for dear life, not just an alfa thing, BMW's suffer from it far more frequently TBH.

what year is the car ?

if its early 06 or earlier you are fine. CF4 was late 06 onwards.
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Engine will be the last thing to die. Check your floorpan for rust. I'll be finishing with my 156 either because of rust (possible this mot unless i can master the welder) or when the clutch goes. I'm probably not going to invest in another timing belt and any big bills will take it to the breakers.
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The car is 2005 face-lift and bought the car on 70000miles
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All good

No flaps....!
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I see one problem on my map sencor the nut that hold the sensor is striped can that cause any problems I took the nut off scared I am going to loose it?
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All good

No flaps....!
After 136k of EGR it's possible the inlet manifold is caked up and restricted with oily soot.

The 2005 1.9's had swirl flaps in the CF3 all-metal inlet manifold, I think, but the less-disastrous older type with an external top linkage that falls off. If the linkage is detached or the flap pivots are leaking you'll probably get a rough idle and lose a lot of power/boost. Certainly worth a look.
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After 136k of EGR it's possible the inlet manifold is caked up and restricted with oily soot.

The 2005 1.9's had swirl flaps in the CF3 all-metal inlet manifold, I think, but the less-disastrous older type with an external top linkage that falls off. If the linkage is detached or the flap pivots are leaking you'll probably get a rough idle and lose a lot of power/boost. Certainly worth a look.
I stand corrected, i did not think we had flaps until 06, but was aware of the CF3 with metal mani/plastic flap arrangement so not as bad as the awful plastic mani /metal flaps CF4 deal...

as halftone said inlet mani could be sooted up good and proper.
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I stand corrected, i did not think we had flaps until 06, but was aware of the CF3 with metal mani/plastic flap arrangement so not as bad as the awful plastic mani /metal flaps CF4 deal...



as halftone said inlet mani could be sooted up good and proper.

I have this combo. The flap seals on top of the manifold started to leak and power was lost because of it. Obviously that bar fell off years ago.

All deflapped now though.


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