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View Full Version : VW Bora 1.9 TDI No Power (110 BHP)



moh
23-04-2007, 11:12 AM
Hi
I have a Bora 1.9TDI 110BHP (1999)

This car has no performance at all. I have changed the turbocharger and air mass. But nothing. I have also serviced the car.
The car doesnít make more then 3000 RPM in the 3rd or 4th or 5th gear .

I have noticed when I press the gas up to 3000 rpm the air tube which connects to the top of the engine turns in to vacuum and its not compressed like it should be. Any ideas ??? (But when I take the tube out I can feel some compression but not much)


Thanks
Moh

ini
23-04-2007, 02:03 PM
Can you hear the turbo spooling up? Sounds like you are not getting enough boost.

I would check everything on the intake side, from the front scoop/MAF back for leaks or blockages. especialy to and from intercooler & check the intercooler is not fouled, and the pipes are connected properly.

Check the braided hose from the actuator on your turbo to the N75 boost control valve is connected and leak free + check N75 electrical connector is seated properly. Also try removing and cleaning out the N75 with WD40 etc, if operation is suspect.

Ensure that the EGR valve is not stuck open/fouled, remove and clean.

Not sure where the manifold pressure sensor is on a Bora, but check that too.

Is your CAT ok, they can block internally (unlikely).

If the boost pipe from the intercooler is not under pressure i would definitely suspect turbo operation/boost control or a blockage in the intercooler/pipes first.

moh
23-04-2007, 02:57 PM
Thank you so much
I will have a look at the parts that you have named
some one told me something regarding a Westgate might be faulty do you think that could be the case ???
I have also had the car cheeked by the VW for any error on the ECU but I got no error

PS do you know any sites with good information regarding the VW turbocharger. I think if I had some clear idea I would be able to understand it more.
Once again thanks for the information.
Moh

ini
23-04-2007, 03:07 PM
Only the 90bhp engines have a wastegate, the 110 engines have a variable vane turbo, which deals with excess boot internally.

You have an 'overboost' problem.

This site shows the cleaning and operation of the VNT-15 turbo quite well.

http://www.technologie-entwicklung.de/Gasturbines/VNT15-Turbo/body_vnt15-turbo.html

Make sure that the small hose which connects to the middle of the round actuator valve on the turbo is connected at both ends.

What is the make and part number on your MAF?

ini
23-04-2007, 03:18 PM
Your overboost problem could also be caused by other things, please look at this thread too:

http://www.vwaudiforum.co.uk/forum/showthread.php?t=7044

moh
23-04-2007, 03:41 PM
hi
Thanks for replay and your help:beerchug:
I will play around with it at the weekend .
Just one last thing
I will tray to explain this as much as I can

example
I am driving in the M1 at 75 MPH when I get to a part which the road is 20% + up hill as I press more on the gas the RPM moves from 2500 to 3000 RPM at this point the gas is all the way down and I am gaining speed to 85 + miles up hill this will go for 5 to 10 second and then loss of power and the RPM start to come down and the speed start to go down
And when this happens the car has no power even in the down hill
I can feel something cutting off but donít know what

Oh and when I disconnect the Air mass plug the car is going much faster in 1 and 2 gear even 3rd in flat areas then when its connected ???

So what do you think of this ???

many thanks
Moh

moh
23-04-2007, 03:55 PM
hi
Glad some one knows 100% what the are talking a bout I have taken this car to so many dealers and spend so much cash on it. If this works I will buy you a drink
Many Thanks
moh

ini
23-04-2007, 04:17 PM
If the car runs better without the MAF connected, your MAF is knackered, and that is causing all your problems.

You can try cleaning it by giving the probe a squirt of solvent through the mesh, but you most likely need to replace it.

Examine both parts of the MAF connector thoroughly for bent pins etc.

Is it a Bosch or a Pierburg MAF?

The current Pierburg MAF for your car is:

Complete MAF part no: 7.18221.51.0 (earlier 7.18221.01.0 is identical)

Just the Pierburg probe/sensor part no: 7.22684.08.0


The Bosch type MAF has a slightly smaller diameter body, and is not interchangeable with Pierburg type. The airbox lid would have to be changed: (you can use the Pierburg probe with small mod)

VW Part No: 06A 906 461

New Bosch Part No: 280 217 121 (latest revision is Bosch 0 281 002 757 or VW 038 906 461C)

Remanufactured: 0 986 280 202

moh
23-04-2007, 04:50 PM
I got the MAF new less then 2 month old from VW dealer. Could it be faulty ??? if I change it and it was the same could it be some thing electronics my part number is 038906461c

ini
23-04-2007, 04:59 PM
If you do have to buy a new MAF, buy it for a FORD Galaxy, the exact same part is cheaper when purchased as a Ford part.

ini
23-04-2007, 05:10 PM
The symptoms you have described are MAF failure, even if it is a new part.

Was the whole MAF changed or just the probe?

The 038906461c is the new 'improved' Bosch type.

moh
23-04-2007, 05:21 PM
how many air flow mass meter dose the car have is it two one cold and one hot ???

ini
23-04-2007, 05:23 PM
Just the one, before the airbox, measures air density/temp/flow.

moh
23-04-2007, 05:37 PM
I have changed the whole thing. Any way of testing the MAF. I will take it back and get the part which you have just named

thanks
i let you know

ini
23-04-2007, 06:19 PM
Does your MAF look like this:

http://www.dieselgeek.com/Detail.bok?no=354

ini
23-04-2007, 07:32 PM
This is the only (non VAG-COM) MAF, N75, and EGR test info i can find, it is for a Pierburg MAF, but the pin-out on the Bosch is identical.

http://www.msi-motor-service.com/ximages/PG_SI_0017_EN_WEB.pdf

Col
23-04-2007, 09:11 PM
A few observations on this one if I may...

Reading back, you mention that the upper hose goes into vacuum? Do you mean it crushes in on itself? If so it could indicate a restriction in the inlet tract. Have you checked the EGR valve for cleanliness? It could be well sooted up.

It also sounds like you are going into limp mode which can be caused by MAF sensor signals out of the expected range of the ECU, sticky vanes on the VNT mechanism on the turbo due to being sooted up, or maybe even a pressure difference caused by a sooted up EGR valve (as above).

I've read reports also of new or re-conditioned MAF's being dud as well, so as Ini has said, don't discount the fact that your new one is ok. Can you find someone off here that has vagcom that is willing to log your MAF, actuall vs ecpected airflow ?

I think, and it's a gut feel that your EGR is clogged full of soot and from your description of the upper hose going into vacuum that that is the cause. Second to that I'd say a sticky VNT. How many miles has the car done (probably above but I've forgotten!).

Good luck.

Eshrules
24-04-2007, 09:56 AM
A few observations on this one if I may...

Reading back, you mention that the upper hose goes into vacuum? Do you mean it crushes in on itself? If so it could indicate a restriction in the inlet tract. Have you checked the EGR valve for cleanliness? It could be well sooted up.

It also sounds like you are going into limp mode which can be caused by MAF sensor signals out of the expected range of the ECU, sticky vanes on the VNT mechanism on the turbo due to being sooted up, or maybe even a pressure difference caused by a sooted up EGR valve (as above).

I've read reports also of new or re-conditioned MAF's being dud as well, so as Ini has said, don't discount the fact that your new one is ok. Can you find someone off here that has vagcom that is willing to log your MAF, actuall vs ecpected airflow ?

I think, and it's a gut feel that your EGR is clogged full of soot and from your description of the upper hose going into vacuum that that is the cause. Second to that I'd say a sticky VNT. How many miles has the car done (probably above but I've forgotten!).

Good luck.

id agree with that, dont just go replacing parts blindly, it could be a costly way of finding the fault.... ideally, you need to get it on vagcom and read the codes. if there are no codes present, fingers crossed, it shouldnt be related to your turbo, lack or excess boost will show itself in the form of a over/under boost code (hopefully). you need to check your MAF sensor, for air flow requested against air flow actual... see how that checks out as Col said. once done, then you can decide on your next course of action, but there are so many common faults when these symptoms exhibit themselves it is impossible to accuratley diagnose without a little investigation :(

belive me, i know how annoying it is, i had a similar problem, 2 days after i had picked mine up from the dealer :(

moh
24-04-2007, 10:02 AM
Just want to say thanks guys for your information. its very useful now i know where to look and how to fix the problem.
i will let you know what was the outcome of work

PS the MAF is the same as the the one in the picture
thank you ini and BigCol :beerchug:
Moh

ini
24-04-2007, 02:24 PM
When Moh mentions a vacuum in the top boost pipe, i think that he is referring to a lack of boost pressure after the car has overboosted, so the car is literally having to suck air in like a normal diesel.

His car works better with the MAF disconected.

The MAF which was new 2 months ago needs to be replaced 'no charge' by the VW ******* he bought it from.

If the problem does not go away temporarily when the ignition is cycled, and there is no related smoke it is MAF/MAP related.

Assuming that the turbo has been installed correctly, It is very very unlikely to be anything else, unless it is bad wiring on the MAF harness.

I do agree that it is very hard to accurately solve this kind of problem without having the car hooked up to diagnostic equipment of some kind.

onzarob
24-04-2007, 03:08 PM
Before you buy a new MAF check the pressure regulator it controls the variable vanes in the turbo, if it fails the ecu cannot controll the N75 valve which regulates turbo boost.

If this is the case the engine will do exactly how you describe it, basically the engine gets to 3000 rpm then the turbo overboosts and the ecu limits the revs to counter act it. witha maf failure the ecu limits the rev to 3000 but the rev don't drop as the ecu can still control the turbo.

I experience this my self last week when the tube connector got broke to the pressure converter

Rob:D

moh
25-04-2007, 11:33 AM
hi guys
just want to say last night I opened the air tube which connects to the top of the EGR and it was oily is it always like this or something is very wrong ???

onzarob
25-04-2007, 12:25 PM
Fortunatley not, this is due to the EGR system.

You can clean the intake manifold to remove this accumalated dirt, but don't try cleaningit on the engine!!.

have you checked the vaccum pipe from the pressure converter to the N75 valve on the turbo for leaks. They will be difficult to spot as the pipes are cotton braided so difficult to check condition. May be worth replacing if your not getting anywhere

Rob:D

Eshrules
25-04-2007, 01:01 PM
yup as above..... you need to get it on a diagnostic machine and check those hoses...

i recently had a problem with my golf... i knew it wasnt turbo or MAF related, because both have recently been replaced, process of elimination and i found the braided hose responsible, simply snipped a bit off so it had a clean, tight fit around the valve it was fitted to... problem solved ;)

redtony
25-04-2007, 07:55 PM
Moh did you sort the problem out? I have the same problem with my bora tdi 90bhp i just bought ;/

Problem noticed are

- No power when on motorway
- Up hill the car slows down

Theres no power in the revs what so ever apart from 1st and 2d, what do 90BHP Bora TDI'S usually rev to ?

redtony
27-04-2007, 08:52 PM
Moh did you sort your problem out, did you replace the MAF?

Anyone know how much MAF sensors cost? or where i could order one at lowest price

thanks in advance