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Discussion Starter #1
Hi to all I am new to this forum.I would like to find out why my alfa romeo 147jtd 16v Has no power under 2500revs I fitted a new maf sensor and the problem still remains pleas any help?
 

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Usually down to a vac leak on the VNT system.

Have a look in the fron tof the engine bay at the small vac lines that go to the actuator on the turbo - a split/crack in one of these will cause the turbo to get stuck in low-boost bost, so the car will feel very lackluster until 2500-3000 rpm... I had it myself when I broke the connectors to the VNT solenoid valve (careful! it's quite fragile!)

Pretty common fault, as the original hoses will get brittle over time. Replace them with some 3mm silicone vac hose, and you're all good.
 

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Discussion Starter #3
Thank for the replay but if I unplug the maf the cars power is back.and the new maf when I put it back the car is completely dead until the revs hit 2500-2800rpm.wil look at the vnt when I get home.
 

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if it were say a vectra diesel i'd say defo EGR valve , is the new MAF a gen one or ebay special ? have you had it plugged into to get codes read ??
 

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Discussion Starter #5
There is no error codes and the maf is genuine bosch part from alfa shop.I cleaned the egr valve and the spring moves freely and cleaned the map sencor no performance increase.and did replace upper and lower turbo hose.
 

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There is no error codes and the maf is genuine bosch part from alfa shop.I cleaned the egr valve and the spring moves freely and cleaned the map sencor no performance increase.and did replace upper and lower turbo hose.
thing is pal , EGR valves dont always bring up a code when they are fubard , anyone close by you could borrow a known good one so you can at least rule it out ??
 

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Discussion Starter #7
Okay thank you for the replay just want to find out the air intake has a flap close to the egr if the car is off the flap keeps open is this normal?
 

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Discussion Starter #8
I found the vnt solinoid at the back of the airbox and the one pipe going up somewhere but I see that the previous owner used pratley steel because the pipe broke off inside the solinoid.
 

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I found the vnt solinoid at the back of the airbox and the one pipe going up somewhere but I see that the previous owner used pratley steel because the pipe broke off inside the solinoid.
Man that feels familiar... My solenoid was gooped up and stuck back together with 2-part epoxy adhesive because it had been ham-fisted before I got the car...

You can get good second hand spares for about £40, so not too severe on the wallet!

Replace the solenoid, get some new silicone lines installed as far back as you can reach (they dive behind the engine to the vac reservoir), and call it job done!
 

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Discussion Starter #10
Thank you now I know where the pipe goes thanx a million.I have another problem my rediator fan is not kicking in I replaced my resistor and fuses and relays still nothing even tested the fan from the battery and it works of the battery any suggestions please?
 

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Thank you now I know where the pipe goes thanx a million.I have another problem my rediator fan is not kicking in I replaced my resistor and fuses and relays still nothing even tested the fan from the battery and it works of the battery any suggestions please?
I believe that fan is switched on by the ECU.. I'd get a laptop/smartphone connected to the ECU and check the coolant temperature it's picking up.
 

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Discussion Starter #12
Will do the ecu checked this weekend.the weird thing is when I put my aircon on the fan kicks in and I did notice the cars temperature pics up slow and when it reaches 90 the temperature goes up and down between 70-90 I did install a new thermostat when I changed my flywheel and clutch plate last year that was a terrible mission to get that gearbox of.
 

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A similar problem on mine was recently resolved with a refurb to the EGR valve.

As I've only had it a couple of weeks I thought the lack of power was due to me being used to 340bhp, but the new EGR valve has made all the difference.

No picks up smoothly/pwerfully from about 1200rpm instead of the 2500rpm.
 

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Hi just had the same problem on my 19 16v and the egr vale had about 1cm of soot blocking it so it was never going to work
totally cleaned it and the sensor which is to the left of it as that was also blocked
she now works as it should with full power from tick over
there is a forum on here that tell you how to take the egr apart
hope that helps Neal
 

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Discussion Starter #15
The problem is my vnt system that is badly damaged but the egr something that's bugging me is the intake manifold has a flap and if the car is off the flap stays open is this normal on a jtdm or is there something wrong.
 

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The problem is my vnt system that is badly damaged but the egr something that's bugging me is the intake manifold has a flap and if the car is off the flap stays open is this normal on a jtdm or is there something wrong.
If its the big butterfly valve on the inlet to the manifold that looks like a throttle, then that's the anti shudder valve.

It's vacuum actuated to close, and only ever operates when stopping the engine... All other times it's held open by a spring I believe.

Many in here have removed the entire assembly to reduce airflow restriction as a performance mod.



As far as the EGR valve goes, best fix is to get it mapped out of the ECU and a blank plate fitted. They're trouble! Without ECU tweaks, you can fit a restrictor plate instead that severely reduces EGR flow and should help the engine breath well.
 

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Discussion Starter #17
Thanx if I blank the egr with the egr still on wil it work and Wat is the chances that the enjin doesn't get damaged.sorry for the stupid questions still new to the alfa world.
 

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Thanx if I blank the egr with the egr still on wil it work and Wat is the chances that the enjin doesn't get damaged.sorry for the stupid questions still new to the alfa world.
It will work just fine, but will generate an "Motor Control System Failure" message on your dash and illuminate the engine management light. Some people have blanked the EGR without mapping, and are quite happy to drive about with this error message present.
 

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Discussion Starter #19
Going to do this tomorrow I need my red pony back in action.what other mods can you do to your car to make it bit better.
 

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Going to do this tomorrow I need my red pony back in action.what other mods can you do to your car to make it bit better.
Loads! The 1.9 JTDm is a great engine to tweak with...

Common mods include but aren't limited to:

  • Remap
  • Bigger/Hybrid Turbo
  • Front mount intercooler
  • Water/Meth injection
  • Bigger injectors
  • Swirl flap removal
  • EGR Delete
  • Exhaust de-cat
  • Braided brake lines
  • Fast road/performance brake pads
  • Coilovers or a decent set of springs/dampers
  • Powerflex suspension bushes
  • Eibach roll bars

There's a load of avid tuners/modders here, check out Damiens build thread if you fancy seeing his journey so far.. He's playing with a GT Cloverleaf, but the GT is pretty much a 147 in a fancy frock so most of the mods will transfer across nicely: http://www.alfaowner.com/Forum/alfa...t-ownership-after-3-year-break-and-build.html
 
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