Turbo or Maf problem??

[sebringbmw]

Hi

I have a MK3 tdi which began having a problem the otherday whereby it accelerated fine, and cruised fine, but if i came off the throttle (esp noticable in 4th and 5th gears) it would put out loads of black smoke, then blue smoke. If i tried to accelerate, it would not go above 2000rpm and be very hesitant - BUT, if i dropped it to 3rd, it would accelerate fine!

Yesterday, i tried to start it but it now just turns over and thats it!

I noticed a rapid ticking when i have the ignition on - comming from the engine bay near the air filter - but cant remember if that is normal or not.

Please help - what could the problem be? Is it the turbo, the MAF, or something else?

Quaser

 

[Vin]

sebringbmw-
This doesn't sound like a MAF problem. You can test for MAF failure by disconnecting it and drive the car around a bit. If you notice any difference then it's MAF. Maybe a clogged of some sort somewhere.

 

[sebringbmw]

Yes, but it doesn't start now!!!

Anything else?

Quaser

 

[sebringbmw]

I put the ignition on today, and the tickng sound had gone!

Tried starting it, and the engine fired up and then died!

But all the intercooler and maf hoses were disconnected!

Q

 

[rdkern]

I'd guess you slipped a tooth on your timing belt. Where are you? You might find someone who is close and who can help.

The ticking might be the N75 and is normal. The smoke is not - and even with the N75 not working, you should be able to get above 2000 rpm, although slowly.

 

[sebringbmw]

OK - Just an update on this guys!

I had the timing belt done and the timing marks are spot on. The car started up on the button when it was completed, but then the next day failed to start again.

I was advised that it might not be pulling fuel up to the injectors, so i checked this and it was the case.

I was told that there maybe a problem with the solinoid or there may be a hole in a fuel pipe!

How do i check these? I had a probe on the solinoid and when 12v is applied to it, seems to click fine!

Is there anything else i could check? Im getting a bit desperate now cause im having to use a petrol car, and its nibbling away at my pocket at a fast rate!!

Thanks

 

[whitedog]

I'd guess you slipped a tooth on your timing belt. Where are you? You might find someone who is close and who can help.

The ticking might be the N75 and is normal. The smoke is not - and even with the N75 not working, you should be able to get above 2000 rpm, although slowly.

A question from someone that is ignorant of the specifics of a TB change:

Is it possible for something such as the tensioner to have come loose causing improper timing and the above mentioned problems?

 

[rdkern]

I am somewhat confused at this point.

You just had the tb changed - I assume within the last week?

Right after that, it started. Did it run? Was it a "start then stopped" routine, or just tested it, it started, and you turned it off?

Next day, it wouldn't start. Was this cranking, but not firing?

Was there a difference in temperature between the two events (starting one day and not starting the next).

Who did the tb change? Was the timing "spot on" absolutely on the middle of the graph as measured by vag-com? Or was this determined by seeing the mark on the cam and ip lining up?

questions, questions, questions....

 

[sebringbmw]

Now not starting

Hi

I had the timing belt changed (it needed doing anyway!)

It started, ran, and was turned off (did not drive it) - Did this about 3 times throughout the day - once by the mechanic, and twice by me.

The next day it cranks over and thats it. Timing was checked by marks on the crank and locked up the fuel pump and locked the camshaft.

Temprature was roughly the same. The mechanic said that it may be the solinoid now - but i have put 12v on the solinoid and can hear it clicking. Unfortunatly, it has siezed into the pump so i can't remove it to check it!

Any tips on how to do that? I have used a 23mm spanner but it is rounding the nut.

 

[rdkern]

Re: Now not starting

Timing should be adjusted and checked with VagCom to get it really right. By sight will often work, but it can be off a tiny bit with respect to the ip and be off enough to give problems with starting.

Do you have fuel in the fuel filter? If you just started/stopped it three times, it might have used up the available fuel in the lines, and there isn't any more readily available. Can you crack one of the injector lines to see if it's getting fuel? Number 3 is generally recommended, although I'm ignorant as to why one is better than any other. If no fuel, figure out why.

When it did start, was there any smoke? If so, I'd probably try to advance the ip a very small touch and try again. If not, I'm at the end of my semi-educated guesses.

Af for the 23mm issue - can you find a 6-sided boxed in wrench somewhere? Very little rounding with the proper tool (I assume you could fit it on).

 

[sebringbmw]

Re: Now not starting

Ok - i forgot to add in the last post that it was because the injectors had no fuel that i was trying to take off the solinoid.

I can't get the socket wrent on it as it is too close to the end and there is a pipe above it anyway?

was there a special tool to remove this?

I was thinking about getting a usb lead off ebay - but where would i get the software from?

Q

 

[rdkern]

Re: Now not starting

Ross Tech has the software, but I'm not sure that the free version can check timing - and it's $99 to activate. If you do have the funds, some feel that the purchase of the cable from ross-tech at 250 or so is well worth it - since it automatically allows the full version of the software to be used.
http://www.ross-tech.com/vag-com/index.html

Also - is the full filter full? If not, get some fuel into it. You can pour some into it or suck it into the filter with a pela or mityvac.

 

[sebringbmw]

Re: Now not starting

ok - i have put fuel in the fuel filter - still not starting
bled the injectors - the fuel is comming up to the injectors, but still not starting!

Used "easy start" after the air flow meter and it starts, revs for a couple of seconds, and then dies!

Any ideas anyone?

Q

 

[rdkern]

Re: Now not starting

Not starting -
(1) engine not going fast enough - which could be the battery or starter. "Easy Start" - assuming ether? - does get it going, so one would think that this would get it over the 600 rpm necessary to get the fuel injected.
(2) Fuel - you say it gets to the injectors (assuming sprays out of the "cracked" ones.)
(3) timing. which is back to where we started. Seems likely to me that you're off a bit.

 

[mindy1701]

Re: Now not starting

You might try testing the injectors to see if there is enough pressure to get fuel through them.

To do this
1) pull the injector pipes.
2) replace one at a 90 degree rotation.
This will have the ends pointing horozontaly and at the engine. I connected then to the top two ports in IP.
I dont remember which one you need to use, use that fits.
3) Pull the injectors
4) install two injector at a time on pipes.
5) Spin the engine there should be a fuel mist coming out of the two injectors.(someone spin engine and someone watch)
6) Repeat for the other two injectors.

the engine will spin easly without the injector installed.

I realize this may be grasping at straws but it sounds like you are not getting fuel into the engine.

Good Luck
Mindy

 

[sebringbmw]

Re: Now not starting

Ok

Now it seems that the glow plugs are not getting a positive feed!

Which fuse/relay do i need to check?

It seems that every mechanic comes up with something else!

Q

 

[jck66]

Re: Now not starting

Glow plugs should not affect startup in August. They don't even preheat unless the temperature is below 40F. This is not your problem.

Just a bit of advice, you may want to fill out your location information in your profile. There may be a helpful forum member willing to give a hand locally.

 

[sebringbmw]

Re: Now not starting

Hi jck66

Thanks for the tip - so, anyone local to me?

Q

 

[sebringbmw]

Re: Now not starting

Ok - so after applying direct power to the glowplugs, and continuosly bleeding the injectors - the car finally started albeit being very very smokey.

At first, it wouldnt rev at all - but then slowly started to rev-up!

My mechanic friend said that it is probably burning all the fuel in the engine up but i am conserned at how much smoke is comming out of the back.

I think i need to wait until i have recieved the lead that i have ordered for the vag-com software and see what that comes up with!

Quaser

 

[Toronto_Vento]

Re: Now not starting

You'll have to register vag-com in order to check the timing by the nice graph they provide. It sounds to me like your timing might be off. If you aren't getting any power to the glowplugs, you might want to check the system out. If you remove the pannel to access the fuse/relay pannel, at the top of the relay block, you'll probably see a 50A fuse and a relay directly below it. That should be the glowplug system. You can also take a look on the firewall in the engine bay. You'll see a small plastic box. Flip it open, and there should be a thin piece of metal spanning between two screws. That is a fuse for part of the glowplug system. Generally, unless the temperature is close to freezing, the glowplugs don't even fire.

To test if they are working properly, unplug the coolant temperature sensor. Then turn the key to the 'on' position. The glowplugs should stay on for a while.

 

[see1964]

I have similiar conditions, I found that my wastegate pressure unit rusted out. Im in the process of repairing it myself. I posted also.

 

[Kayakkermit]

Re: Now not starting

You'll have to register vag-com in order to check the timing by the nice graph they provide.

Dumb question : I have registered, was trying to figure out how to do this but apparantly I'm not that bright.

Could you please tell me how to do this?

 

[Dave_D]

Re: Now not starting

You can call up the timing graph by going into the measuring blocks, selecting block 0, going into "basic" mode and then hitting the "timing" button. Of course you need the engine running to do this.

 

[sebringbmw]

Hi There see1964

Do you have more info on this? Any pics you could send me?
tdi@raj4.com

Thanks

Q