[Dave wroe]

Hello to all the Alfa wizards and magicians on here. Newbie Alfa owner. First of let me say I LOVE my Alfa but god she's giving me grief! 2004 gt 1.9jtd. Keep getting the dreaded MCSF fault with codes P0236 & P0238. I've trawled through nearly every post on here so here's what I've done so far,
Removed/cleaned egr valve, blanked with Alfa approved parts (ones with holes)
Cleaned MAP sensor. (Looked like lump of coal!)
Checked/listened for leaks on pipe work I can see.
I haven't cleaned the MAG yet as reluctant to disconnect electrics just yet!!!!!!
Here my prob at the moment. Now I don't have any boost till approx 3000 rpm! I'm going to check the turbo for any stuck actuator but I'm struggling with part location so if anyone can post any detailed photos of where things are on the engine I would be forever grateful!
I'm competent with a spanner but my location finding is dreadful! Any help is much appreciated.
Over to you wizards now.
Thanks guys.

 

[Dave wroe]

MAF not mag!!!!!!!!! ???

 

[joeymannero]

ok...


fairly common issue on all modern diesels this, not just Alfa, that its coming in so late strongly implies sticky/stuck VNT or a split or tear in the little vac hose that actuates it.

Maf is a strong candidate also as is Map sensor..cleaning the MAF on these is a bit hit and miss sometimes works sometimes doesn't. if you do replace it must be a genuine bosch item or the car will reject it in short order.

ok now to the location,from under the car you should be able to see the the actuator, its a circular steel arrangement with the vac hose coming from out of the middle... reach around that and there is the actuator rod..you should be able to move it.

here is a youtube link of the turbo off the car, should help you to visualize what you need to do do and what it look like..

https://www.youtube.com/watch?v=wcDZWI1g_jE

hope that helps:thumbup:

 

[Dave wroe]

Thank you joey. Great help. I've cleaned the MAP sensor (not to say that could be buggered) but reading other posts I think your right it does point to stuck vnt so will try to tackle that tonight at work if I get time. Again thanks for the vid and comp location as that's what was holding me up. (Looking for turbo from the top!) will post updates on progress.

 

[Dave wroe]

Sooo. Here's the latest. Today cleaned up the MAF sensor, vnt on the turbo was moving ok. Went for a spin, initially she revved into the red but still no boost! By the time I got back home. (2 mile round trip) wouldn't rev past 3500 again!!!!!
Any other suggestions before I bite the bullet and send it to the local "specialist"? Really can't afford to pay out for work already done!
Thanks chaps.

 

[Dave wroe]

Another quickie, how do I check if the sensors/plugs are duff? Have a multi meter but don't know what readings and what pins to check!!

 

[dgmayhead]

Map sensor should read 101kpa at atmospheric. From memory I think max boost is 1.5bar. Sorry to mix my units.

 

[Dave wroe]

Map sensor should read 101kpa at atmospheric. From memory I think max boost is 1.5bar. Sorry to mix my units.

Thanks for info, unfortunately I don't have a pressure tester or diag! (Used my ex mechanics one) looking for possible volt/resistance values of map and MAF so I can at least eliminate before I spend obscene amounts on new ones! But good info to have cheers.

 

[dgmayhead]

Thanks for info, unfortunately I don't have a pressure tester or diag! (Used my ex mechanics one) looking for possible volt/resistance values of map and MAF so I can at least eliminate before I spend obscene amounts on new ones! But good info to have cheers.

Well worth getting a cheap reader or phone app just to get some data. Shouldn't cost more than £20.

 

[halftone]

Disconnect the MAF temporarily, idle will be awful but if the car revs better that points to the MAF being faulty.

How do you know VGT is working right? eLearn says 1cm movement at the lever, but it's more like 2cm and the lever must go fully forward to the stop. Mine had 1cm but was sticking half-way, due to what turned out to be surface rust on the inside of the turbo casing obstructing vane movement. It's hard to see and hard to move by hand. The best way to check is to use a cheap vacuum pump off eBay. Like this, although you might find similar cheaper. The week after I bought one I saw some for half this price on eBay.
http://www.ebay.co.uk/itm/Hand-Held...cuum-Pump-Car-Motorbike-Bleeding/201025017182

 

[Dave wroe]

Just downloaded fiatecuscan and ordered some leads so should arrive in couple of days
I can move the vnt actuator about 1-2cm and gave it a spray/clean but do think it's probably gunked up a bit! Will disconnect the MAF tomorrow and have a go at that. If I can't pinpoint it I'll have to bite the bullet and book it into my local indi Alfa garage. Thanks for the help chaps will post updates if I ever get to the bottom of it!

 

[Dave wroe]

Right guys. Just disconnected the MAF and went for a spin, yee bloody haa got my boost back!!!! Still a bit sluggish low down revs but putting this down to the bag of bones it is New MAF on order. However is it ok to drive with it disconnected until new one gets here?
Hopefully this sorts it out (until the next issue pops up)! Talking of which, since I had the batt removed for MAF cleaning my drivers window won't auto drop on one button press have to hold button down/up will do a soft reset later. Just happy I've hopefully found the issue with boost.
Many many thanks for your help guys. You really are Alfa wizards!

 

[dgmayhead]

Bosch part only for replacement and no harm is done by driving with maf disconnected.

 

[Dave wroe]

Yep. Got part from autolusso today. Fitted and cleared codes. Took for a spin and still no boost!!!! Starting to get frustrated now! Next thing I suppose is remove the turbo and clean it up?
The one code I did Have was egr valve restricted flow? Is this because I have it blanked with holes in the blank? Can't remember the code number!
Is turbo removal a straight forward job? I'm quite handy with a spanner but do have limited tools!

 

[dgmayhead]

Before the turbo and vanes are investigated. Blank the egr completely and see if this makes a difference.

 

[halftone]

Your disconnection test seems to have localised the issue to the MAF so I'd try disconnecting this new MAF and see if your boost returns again, just in case the new one is faulty. Also have a good look at the MAF wiring and clean the plug with contact cleaner.

Was the code P10401? A restrictor plate at the EGR shouldn't give that fault. It suggests the EGR is defective/blocked or the manifold is choked or MAP sensor defective, or boost hose leaking/split. Or it may just be a symptom of a still-malfunctioning MAF. These things all interact, which is why fault-finding is tricky and must be methodical.

A full blank will cause that code but it doesn't cause limp mode so you can drive around normally with a blanked EGR. But it seems you're getting limp mode so I think you need to note the codes and post here.

I wouldn't touch the turbo yet. It's not a big job but it is awkward (putting it back is, anyway) you do need some odd-shaped spanners and Capuchin monkey hands. There's no point removing it if there's nothing wrong with it, and lack of boost seems to be due to limp mode rather than the turbo itself. If you want to check, spending a tenner on a cheap vacuum pump so you can test actuation may save you wasting time and money.

 

[Dave wroe]

Latest update took off turbo hoses, no splits, bottom one is silicone already! one of the vacuum hoses wasn't seated right and had been cut too much on installation. Sorted that. Checked MAF wiring. Looks ok still no boost and now it's slow to rev!!!!! No codes present. Was an egr code pending but cleared that as I had it off again. Not come back, still slow to rev and some black smoke! Getting really frustrated now as I need the car tomorrow!
Got someone to check the vacuum actuator for me, moves on start up, no movement when revving, no movement on shut down? Can move it al the way to the stop with my fingers, could it possibly be the solenoid causing this??? ANY help appreciated! Pulling what little hair I've got out now!

 

[Dave wroe]

Latest latest!!! Got a call back from a very nice chap at go-Italia. (Local Indy Alfa place in Maidstone) I explained the symptoms and the remedies I've tried already, he told me to clamp the vac pipe from the solenoid to the turbo vacuum and take it for a spin. Nearly ALL my boost was back. Soooo this all points to the pressure converter ( solenoid control) part on its way. Will let you all know if this cures it once and for all!
Also does anyone think it will be ok to use it clamped? Need it for work????

 

[sussexa]

or a leak in the vac hose to solenoid somewhere after where it was clamped.
suggest some new silicone hose for the vac if your changing solenoid anyway, seen plenty of posts where the hose splits cos brittle.
if the actuator was receiving full vac at the time it was clamped and held in full 75% spool position im not supprised youve got boost back just be careful as it would be easy to overboost/overspeed the turbo in higher revs if this is the case, the ecu would be trying to reduce it to say 30-40% but as you have it clamped it will not reduce.
just be careful id say youd be fine as long as you use common sense and realise your right foot will be controlling boost not ecu.

 

[halftone]

Doh. Sussexa has probably nailed it there: a couple of feet of 3mm ID silicone turbo hose is probably all you need, or as a temporary fix a good wrap of electrical tape round where the hose is leaking.