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Discussion Starter #1
Hi all,

Yes its another JTD power loss issue, read on if you dare!!!!

New to the alfa but been around JTD's for a while and have experienced most of there problems first hand but I still cant get enough of them for some strange reason :D

Since owning this one its been low on power to what I was expecting but initially put it down to a mixture of A) the car not been driven more than 3k miles in the last 3 years and B) my expectations being higher than it should have been! But after several weeks and lots of motorway action later, the power still has not returned.

I have now had her along to my local diesel specialist for diagnostics etc but he cant find anything other than the MAF giving off a very low signal. Hes tried replacing the MAF with another bosch unit but the reading stayed the same! Hes checked the whole air intake for any blockages and cant find anything there either. Turbos also been checked (must be an earlier version non-variable) wastegate operation is fine as well.

The next problem is its an 09 2000 model which seems to be the cross over period on MAF's by the looks of things! I'm wondering if the incorrect MAF has been fitted before i got it? My diesel guy is of the opinion its injector related so i've got her on a dose of anti-biotics (redex!)

Any ideas? PS. The EGR has had its opperation checked and is ok, i've even blocked it off to see if that would help but its made no difference. Diagnostics is clean. Turbo spools, dumps, has no aparent leaks but gives no signs that its being used by the engine!!!! Loosing.... will... to live :cry: lol
 

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Discussion Starter #3
Thanks for the reply Shaz, I was originally thinking along those lines but all Bosch MAF's read 0-5amps as far as i'm aware (unless someone can tell me different) so the only difference in part number on these units would be for variations in the housing for pipe bore size and shape and possibly for different plug connections?

Thanks again for the input tho! Fuel system treatment has been working to a degree with improved throttle response and a slightly better "umph" from the turbo but its only minimul so far. I'm going to keep going with more treatments for a few more weeks to see if it keeps getting better.....
 

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Hi.

Did you sort it out? I have the same problem. 2 MAF sensor changed and low readings, also power comes above 2500 rpm.

Raf.
 

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Discussion Starter #6
Not really mate, its still under powered to be honest but some days its better than others..... the power comes in after 2500 all the time but some days it REALLY pulls and others it doesnt. Injector cleaner made only a small difference, new filter made little difference, never checked the MAP sensor yet as i've never really had time.

I was just going to buy one of the ebay tuning boxes to bump up the fuel pressure for £90 and see what happened?!?! I've used them before and they work quite well so if the fuel pressure and delivery is incressed then the ecu should start pulling more air in to compensate which would also increase the amount the turbo is boosting. If it just produces smoke when its fitted and has no power increase then its coming back down the electrics and the maf is not getting enough power into it to produce a high enough signal?

Thats my thoughts on it anyway.... its cheaper than replacing injectors, map sensors and god knows whatever else only to find non of it has worked and the maf still keeps spitting out low readings. I'll have one of the plug in chips within the next few weeks to test it and see what happens
 

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quite interested in this, i have much the same issues and its none of the usual problems that cause power loss (egr, split pipes etc). how exactly did you test the strength of the signal the maf outputs?

does yours smoke at all?
 

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Discussion Starter #8
I took it to my local diesel specialists (Just Diesels in Newcastle) who done a full diagnostics check and found low air flow and low boost readings from there. They thought it was possibly a blocked / fouled injecter and prior to taking them out and testing them all (which was going to cost a few quid!) they suggested diesel injector treatments for a few month to see what happened or see if the problem developed further to help them track the cause. It did improve things and reduced what little smoke was coming off her. I had been getting a small amount of white smoke which would kind of indicate unburnt diesel followed by the usual black soot..... thats now cleared since injector treatment but it still doesnt feel as good as it should.

With common rail diesels they will only take in the correct amount of air to burn whatever diesels going in so if theres not enough diesel hitting the chambers then only a small amount of air will be drawn in.... if theres only a small reading coming from the MAF then the Boost Solinoid will only use a small amount of turbo. Thats why i'm going for tuning chip to jack up the fuel pressure and see what happens
 

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My Alfa is chipped. Still no power before 2500. Where did you get that MAF sensor from? My one is from euro car parts. Poeple from Angel tunning say that I should buy parts from Alfa shop. I'm thinking to buy new EGR valve, maybe this will solve my problem, or get new MAF sensor from Alfa shop.
 

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Discussion Starter #10
If its already chipped and still not pulling below 2500 then I would say your problem is with the egr valve and is a different problem to mine (just sold a brand new spare egr I had unfortunately) but I would recommend getting a diagnostic done at an independant diesel specialist.... it should only cost about £40 compaired to about £80 at an Alfa Dealer. That should pin point your problem before you go spending money on parts.

My maf sensor is still the original one!!! The diesel specialists I took it to were Bosch agents and they tried another maf in her to check if that was the problem but even the brand new bosch unit they used still gave low air flow readings
 

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Hi.

Every time I change MAF sensor these error codes showing up. Original Bosh of course

1. P0101 . Mass/volume airflow sensor range performance problem.
2. P0110 . Intake air temperature sensor - circuit malfunction.

No error codes from EGR valve. This is really strange.
 

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Discussion Starter #12
What year of manufacture is yours? 135 bhp 150bhp?

I didnt get any error codes from mine as far as i'm aware, just low readings
 

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I had these exact symptoms (low power, no boost until 2500rpm and wierd low and over boost errors), changed the MAF, cleaned and checked the EGR and made no difference. In the end I tracked it down to the little vacuum host that runs from a solenoid at the top of the cooling fans down through the centre of the fans and out the bottom into the turbo. Its tiny little hose that you'd probably not give a second glance to. It actually controls the VVT system and changes the turbo vanes so that boost is varied.

Mine is a 1.9 JTD 16v but I assume similar is present on the 10v and 20v. Hope it helps.
 

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I had these exact symptoms (low power, no boost until 2500rpm and wierd low and over boost errors), changed the MAF, cleaned and checked the EGR and made no difference. In the end I tracked it down to the little vacuum host that runs from a solenoid at the top of the cooling fans down through the centre of the fans and out the bottom into the turbo. Its tiny little hose that you'd probably not give a second glance to. It actually controls the VVT system and changes the turbo vanes so that boost is varied.

Mine is a 1.9 JTD 16v but I assume similar is present on the 10v and 20v. Hope it helps.
you mean the geometry controller dont you, not vvt, as diesels dont have that;)

i wouldnt try upping the fuel pressure either incase the injectors are faulty. id make sure there ok 1st.

could be the fuel pump to;)

take it the intercooler pipes have been checked too?
 

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Ooops meant VNT not VVT.
aaaah:lol:

could be the actator on the turbo stuck aswell. the throat section could be stuck on small, which would mean the turbo isnt getting the required air to spool fully:(

coud also be the turbo dying too, that would explain the white smoke:(
 

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Discussion Starter #18
aaaah:lol:

could be the actator on the turbo stuck aswell. the throat section could be stuck on small, which would mean the turbo isnt getting the required air to spool fully:(

coud also be the turbo dying too, that would explain the white smoke:(

Right well mine is a 2000 X reg, not sure what the engine code is to be honest. As far as i'm aware mine does not have VVT errrr VNT lol as it has a wastegate which VNT's dont???

Turbo + wastegate operation has been checked and working correctly. The white smoke was only when I first got the car and has cleared since using injector cleaner. All pipework has been checked and is "split free"!!!

RafiK - Just wondering if if you've tried disconnecting your MAF and driving it to see if there's any difference? Could be a wiring problem and the MAF is getting no power, if it drives the same disconnected then it definetly isnt getting any power to the MAF. Mine turns in to a real dog if i disconnect the MAF wires!

I'm starting to think my problem could be either fuel pump or high/low pressure unit starting to pack up? Anyone got any links or parts lists for the various JTD engines or anything? My log book says its a 150bhp but i'm sure its the earlier 136 engine thats in it... fueling and egr systems seem quite different on them all :confused:
 

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No error codes from EGR valve. This is really strange.
there is no feedback from the EGR valve or other readings for your car so problems with the EGR won't get reported.

Right well mine is a 2000 X reg, not sure what the engine code is to be honest. As far as i'm aware mine does not have VVT errrr VNT lol as it has a wastegate which VNT's dont???

Turbo + wastegate operation has been checked and working correctly. The white smoke was only when I first got the car and has cleared since using injector cleaner. All pipework has been checked and is "split free"!!!

RafiK - Just wondering if if you've tried disconnecting your MAF and driving it to see if there's any difference? Could be a wiring problem and the MAF is getting no power, if it drives the same disconnected then it definetly isnt getting any power to the MAF. Mine turns in to a real dog if i disconnect the MAF wires!

I'm starting to think my problem could be either fuel pump or high/low pressure unit starting to pack up? Anyone got any links or parts lists for the various JTD engines or anything? My log book says its a 150bhp but i'm sure its the earlier 136 engine thats in it... fueling and egr systems seem quite different on them all :confused:

Well a 2000 won't be a 150bhp, the 150bhp only came in in about '02 (IIRC), however your's could be the 140bhp (which is the same as the 150 just with a different map) ...

... you seem quite convinced that the 136bhp has a wastegate, however I'm pretty convinced that the 136 uses VNT as well as the 140/150 versions and as such doesn't have a wastegate ...


... you could get hold of a copy of alfadiag and read out the real-time values yourself, the fuel pressure (IIRC) should be around about 1200-1800 psi, don't know what typical MAF values should be though I'm afraid.
 

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Looking through ePer the 136bhp was discontinued in 06/1999 ... so yours is probably the 140bhp ...
 
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